Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (180)
  • 1955-1959  (7)
  • 1950-1954
  • 1940-1944
  • Agrobacterium
  • Brassica napus
  • 1
    ISSN: 1432-203X
    Keywords: Agrobacterium ; auxin biosynthesis genes ; barley and tobacco protoplasts ; transient expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Agrobacterium tumefaciens and some Agrobacterium rhizogenes strains possess auxin biosynthesis genes (tms and aux genes respectively), responsible for a de novo auxin biosynthetic pathway in transformed plant cells. A comparison is presented of the potential expression of these genes in a monocotyledonous (barley) and a dicotyledonous plant (tobacco). The promoters of the genes were translationally fused to the β-glucuronidase reporter gene and analysed in transient expression experiments. The tms and aux fusions were highly expressed in tobacco, but not in barley. However, the aux enhancer active in tobacco, conferred low β-glucuronidase expression in barley when fused to a truncated cauliflower mosaic virus 35S promoter. The results are discussed in relation to the differential responses to Agrobacterium infection in monocots and dicots.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell reports 14 (1994), S. 59-64 
    ISSN: 1432-203X
    Keywords: Agrobacterium ; transformation ; T-DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three chrysanthemum (Dendranthema grandiflora) cultivars were cocultivated with 2 Agrobacterium tumefaciens strains in combination with 4 pBIN19 derived binary plasmids, all carrying the Nosnptll selection gene and 35Sgus(intron) reporter gene. All binary plasmids transferred DNA to chrysanthemum explants but only pMOG410 gave good stable expression of GUS. This plasmid differs from the other plasmids in 2 aspects: 1) It carries a restored nptll gene and 2) the selection gene is positioned at the left border side of the reporter gene. Cocultivation with AGLO(pMOG410) yielded up to 13 GUS positive shoots per 100 explants. The presence of the gus and nptll gene in recovered shoots was confirmed by PCR and Southern blot analysis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell reports 13 (1994), S. 145-148 
    ISSN: 1432-203X
    Keywords: muskmelon ; gene transfer ; Agrobacterium ; regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cotyledon explants of muskmelon (Cucumis melo L., cv. Amarillo Oro) seedlings were co-cultivated with disarmed Agrobacterium tumefaciens strain LBA4404 that contained the binary vector plasmid pBI121.1. The T-DNA region of this binary vector contains the Nopaline synthase/neomycin phosphotransferase II (NPTII) chimeric gene for kanamycin resistance and the Cauliflower Mosaic Virus 35S/β-glucuronidase (GUS) chimeric gene. After infection, the cotyledon pieces were placed in induction medium containing 100 mg/l kanamycin. Putative transformed shoots were obtained, followed by the development of morphologically normal plantlets. The transgenic nature of regenerants was demonstrated by polymerase chain reaction, Southern blot analysis, plant growth on medium selective for the transgene (NPTII) and expression of the co-transformed GUS gene. Factors affecting the transformation procedure are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-203X
    Keywords: Medicago sativa ; Alfalfa ; Transformation ; Agrobacterium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The trait for somatic embryogenesis is being introduced sexually into alfalfa (Medicago sativa) breeding populations to facilitate genetic transformation of this crop. Cocultivation experiments were conducted with an agronomically-improved embryogenic clone from one such population as well as with two other embryogenic clones, one of which was the source of the embryogenic trait in the breeding populations. Transgenic plants were produced from the agronomically-improved clone whereas none were produced from the other two clones. Among the 16 transgenic plants analyzed there was a range in both copy number and number of integration sites for the NPT-II gene; those plants regenerated after a prolonged selection phase in vitro generally had the highest numbers in both respects. There was no evidence of sectoral chimerism of the transgene in a subsample of transgenic plants analyzed by PCR.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-203X
    Keywords: Ammonia ; Agrobacterium rhizogenes ; Brassica napus ; glutamine ; glutamine synthetase ; phosphinothricin ; rape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Hairy roots of Brassica napus (rape cv. Giant) were produced by cocultivating leaf and cotyledon explants with Agrobacterium rhizogenes strain A4T. The hairy roots grew prolifically on solid and in liquid media. Incorporation of ammonium sulphate or phosphinothricin (PPT) into the media reduced growth. PPT treatment reduced glutamine synthetase (GS) activity and increased the ammonia content of the hairy roots. We have found that PPT treatment also induces a loss of glutamine from the roots and this may influence root growth. To test this we grew hairy roots in a liquid medium containing 10 mM glutamine. This glutamine treatment overcame the PPT induced suppression of growth but also significantly increased GS activity, reduced ammonia accumulation and increased the levels of glutamate and asparagine.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 161 (1994), S. 300-309 
    ISSN: 1432-072X
    Keywords: Agrobacterium ; 16S rDNA ; 16S rDNA-23S rDNA Intergenic spacer ; tmr Gene ; nos Gene ; virA Gene ; virB2 Gene ; Polymerase chain reaction ; Restriction fragment length polymorphism ; Crown gall
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chromosomes and Ti plasmids of 41 Agrobacterium strains, belonging to biovars 1, 2, 3, and Agrobacterium rubi species were characterized by the restriction fragment length polymorphism of PCR-amplified DNAs. Profiles that were obtained by the analysis of the amplified 16S rDNA confirmed the grouping of the strains according to their species. Higher polymorphism was detected in the intergenic spacer between the 16S rDNA and 23S rDNA genes, allowing efficient discrimination of strains. Identification of most strains was possible, and the genetic relatednesses of Agrobacterium strains could be estimated. The analysis of the plasmid Ti encoded regions between the tmr and nos genes, and the virA and virB2 genes, allowed fingerprinting of Ti plasmids. Genomic typing by the rapid PCR-RFLP method is thus shown to be useful for an independant identification of strains and of the conjugative Ti plasmids.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-072X
    Keywords: Agrobacterium ; β-1,2-Glucan ; chvB Mutants—Ca2+
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The chvB gene of Agrobacterium tumefaciens encodes a 235 kDa proteinaceous intermediate involved in the synthesis of β-1,2-glucan. chvB mutants show a pleiotropic phenotype. Besides not to produce cyclic β-1,2-glucan, chvB mutants have been reported to be avirulent, attachment-deficient, and nonmotile. In this study we report additional differences from the parent strain, probably all linked to changes in the cell envelope. This pleiotropic phenotype — except for attachment and virulence — could largely be prevented by growing chvB cells with low levels of calcium. Although a role for β-1,2-glucan in osmoadaptation has been proposed, the mode of action of β-1,2-glucan is not known. We speculate that in A. tumefaciens β-1,2-glucan stabilizes membranes, which would be important especially in hypotonic media containing calcium.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-5028
    Keywords: Agrobacterium ; gene regulation ; sensor protein ; signal transduction ; VirA protein ; acetosyringone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The VirA protein ofAgrobacterium tumefaciens is thought to be a receptor for plant phenolic compounds such as acetosyringone. Although it is not known whether the interaction between VirA and the phenolics is direct or requires other phenolic-binding proteins, it is shown in this study that the first 280 amino acids of the VirA protein are not essential for the acetosyringone mediatedvir gene induction response. Considering the fact that the cytoplasmic region between the amino acids 283 and 304 is highly conserved between the different VirA proteins, and that deletion of this region abolishes VirA activity, we suggest that the acetosyringone receptor domain is located in this cytoplasmic domain of the VirA protein.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 25 (1994), S. 989-994 
    ISSN: 1573-5028
    Keywords: Agrobacterium ; binary vectors ; gentamycin resistance ; kanamycin resistance ; tobacco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The newpPZP Agrobacterium binary vectors are versatile, relatively small, stable and are fully sequenced. The vectors utilize the pTiT37 T-DNA border regions, the pBR322bom site for mobilization fromEscherichia coli toAgrobacterium, and the ColE1 and pVS1 plasmid origins for replication inE. coli and inAgrobacterium, respectively. Bacterial marker genes in the vectors confer resistance to chloramphenicol (pPZP100 series) or spectinomycin (pPZP200 series), allowing their use inAgrobacterium strains with different drug resistance markers. Plant marker genes in the binary vectors confer resistance to kanamycin or to gentamycin, and are adjacent to the left border (LB) of the transferred region. A lacZ α-peptide, with the pUC18 multiple cloning site (MCS), lies between the plant marker gene and the right border (RB). Since the RB is transferred first, drug resistance is obtained only if the passenger gene is present in the transgenic plants.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-5028
    Keywords: anther ; antisense RNA ; Brassica napus ; male fertility ; tapetum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An antisense approach was used to attempt to determine the function of the highly abundant, tapetum-specific A9 transcript in microsporogenesis. A Brassica napus A9 cDNA clone was linked in sense and antisense orientations to the Arabidopsis thaliana A9 promoter and the resulting chimaeric genes introduced into B. napus. A high proportion of the offspring of B. napus antisense A9 plants had very low or undetectable levels of A9 mRNA. However, these plants set seed and had pollen of normal or near normal viability. Therefore, under the conditions studied, the A9 protein appears not to be essential for male fertility in B. napus.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 1573-5028
    Keywords: Agrobacterium ; attachment ; plant receptor ; rhicadhesin ; Rhizobium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Attachment of Rhizobium and Agrobacterium bacteria to cells of their host plants is a two-step process. The first step, direct attachment of bacteria to the plant cell wall, is mediated by the bacterial protein rhicadhesin. A putative plant receptor molecule for rhicadhesin was purified from cell walls of pea roots using a bioassay based on suppression of rhicadhesin activity. This molecule appeared to be sensitive to treatments with pronase or glycosidase. Its isoelectric point is 6.4, and its apparent molecular mass was estimated to be 32 kDa before and 29 kDa after glycosidase treatment, as determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and ultrafiltration. The sequence of the first 29 N-terminal amino acids was determined: A-D-A-D-A-L-Q-D-L-C(?)-V-A-D-Y-A-S-V-I-L-V-N-G-F-A-S-K(Q)-(P/Q)-(L)-(I). No homology with known proteins was found. In the course of this research project the extracellular matrix protein vitronectin was reported to inhibit attachment of A. tumefaciens to carrot cells [29]. A variety of adhesive proteins, including vitronectin, contain a common cell attachment determinant with the sequence R-G-D. Since we could not detect other cell wall components able to suppress rhicadhesin activity, and since an R-G-D containing hexapeptide was also active as a receptor, we speculate that the plant receptor for rhicadhesin is a glycoprotein containing an R-G-D attachment site.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 24 (1994), S. 223-227 
    ISSN: 1573-5028
    Keywords: Brassica napus ; dehiscence ; dehydrogenase ; pod ; protochlorophyllide reductase ; shatter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Dehiscence of oilseed rape pods, commonly known as pod shatter, is a process of agronomic importance that results in seed loss causing yield reductions and carry-over of the crop into the following growing season. In an effort to understand the mechanisms underlying this developmental event, the changes in gene expression that accompany pod shatter have been examined with a view to understanding how the process is regulated. In order to achieve this, a cDNA library was constructed using mRNA extracted from the dehiscence zone of developing pods. Differential screening with non-dehiscence zone cDNA led to the isolation of a pod-specific clone, SAC25, with a transcript size of 1100 nucleotide encoding a predicted polypeptide of 34 kDa. The level of SAC25 mRNA accumulation increased during pod development. The sequence shows no significant homology to others within the databases but has two identifiable amino acid motifs, one is an adenine nucleotide binding site for NAD/FAD dehydrogenases and the other is a conserved feature of the ribitol dehydrogenase family. The amino acid sequence has four putative glycosylation sites and contains four cysteine residues. Genomic Southern analysis indicates that SAC25 may be encoded by a single gene or a small gene family. The function of this mRNA is unknown but possible roles in dehiscence and pod development are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1573-5028
    Keywords: abscisic acid ; ABA-response element ; bi-directional promoter ; Brassica napus ; oleosin ; seed development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In Brassica napus, oleosins are expressed at high levels in the seed during the latter stages of embryo development. The cis-acting regulatory properties of an 872 bp promoter fragment of a B. napus oleosin gene were examined by analysis of β-glucuronidase (GUS) expression in transgenic tobacco plants containing an oleosin promoter-GUS transcriptional fusion. The reporter gene was expressed at high levels only in seeds, specifically in embryo and endosperm tissue and regulated throughout seed development. These data demonstrate that oleosin gene transcription is regulated in a tissue-specific and temporally regulated manner and clearly indicate that oleosin protein expression is co-ordinated primarily at the transcriptional level. Oleosin mRNA was shown to be abscisic acid (ABA) inducible and an ABA-response element in the oleosin promoter was shown to be bound by a protein factor in a sequence-specific manner. Sequence analysis of the oleosin promoter has identified several other putative cis-acting sequences which may direct oleosin gene expression. The presence of a large open reading frame in the bottom strand of the oleosin promoter (ORF2) which encodes a polypeptide similar to the ethylene-induced E4 gene of tomato is reported. A PCR-generated DNA probe containing the ORF2 sequence hybridised with a 1.4 kb transcript in total RNA extracts of a variety of tissues, including leaves and germinated seed cotyledons. This finding suggests that the oleosin gene promoter directs transcription in both directions. It is the first report of a bi-directional nuclear gene promoter in plants.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1573-5028
    Keywords: Brassica napus ; Enoyl-ACP reductase ; isoforms ; stearoyl-ACP desaturase ; developmental expression ; seed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The expression of mRNA and the steady-state levels of two-component enzymes of plant fatty acid synthetase (FAS) were studied. Northern analysis of enoyl-ACP reductase (ER) and stearoyl-ACP desaturase (SD) gene expression showed that steady-state levels of both transcripts increase during lipid deposition in the seed reaching a maximum at 29 days after flowering (DAF). The steady-state level of ER message falls very quickly after reaching its maximum, whereas the SD message is longer-lived. The levels of these specific mRNAs in seed are 15–30 times greater than in leaf. Optimum mRNA expression precedes the maximum levels of synthesis of the two proteins, which in turn precede the maximum level of oil. The expression of isoenzymes of ER were examined by two-dimensional western blotting in both leaf and seed tissue. Four enzymes are expressed in both of these tissues; the two most abundant isoforms in seed material are also the most abundant in leaf tissue.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1573-5028
    Keywords: Brassica napus ; napin ; antisense ; seed storage protein ; seed storage lipid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To manipulate the quantity and quality of storage components in Brassica napus seeds, we have constructed an antisense gene for the storage protein napin. The antisense gene was driven by the 5′-flanking region of the B. napus napin gene to express antisense RNA in a seed-specific manner. Seeds of transgenic plants with antisense genes often contained reduced amounts of napin. In some transgenic plants, no accumulation of napin was observed. However, the total protein content of transgenic and wild-type seeds did not differ significantly. Seeds lacking napin accumulated 1.4 to 1.5 times more cruciferin than untransformed seeds, although the oleosin content was not affected. Fatty acid content and composition in the seeds of transgenic plants were also analyzed by gas chromatography. Though the total fatty acid content of the transformants was the same as that of non-transformants, there was a reduction in 18:1 contents and a concomitant increase of 18:2 in seeds with reduced napin levels. This observed change in fatty acid composition was inherited in the next generation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1573-5028
    Keywords: Brassica napus ; heterologous expression ; Rab/Ypt family ; small GTP-binding protein ; vesicular transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA clone (bra) encoding a small GTP-binding protein was isolated from Brassica napus by screening a root cDNA library with a degenerate oligonucleotide probe that corresponds to a highly conserved GTP-binding domain of the Ras superfamily. Sequence analysis shows that the clone contains an open reading frame of 219 amino acid residues with the estimated molecular mass of 24379 Da and this coding region contains all the conserved motifs of the Ras superfamily. The deduced amino acid sequence of the bra gene is most closely related to the Ypt/Rab family that functions in the vesicular transport (46% and 47% amino acid identity to the yeast Ypt1 and to the human Rab1, respectively) and is more distantly related to the other Ras-related families. The protein encoded by the bra gene, when expressed in Escherichia coli, shows the ability to bind GTP. Furthermore, when the bra gene is introduced into Saccharomyces cerevisiae under the regulation of the yeast GAL1 promoter, the gene can complement the temperature-sensitive yeast mutation ypt1-1 that has defects in vesicular transport function. The amino acid sequence similarity and the functional complementation of the yeast mutation suggest that this gene is likely to be involved in the vesicular transport in plants. Genomic Southern analysis shows that this gene is a member of a small gene family in Brassica napus.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; Brassica napus ; gene expression ; Nicotiana tabacum ; retrotransposon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The expression of the tobacco (Nicotiana tabacum) retrotransposon Tntl has previously been shown to be strongly regulated and driven from the 5′ long terminal repeat (LTR). We report here that the Tntl LTR can promote activity of the β-glucuronidase (GUS) reporter gene in two heterologous species of the Brassicaceae family, namely rapessed (Brassica napus) and Arabidopsis thaliana. The translational LTR-GUS fusion was active in transient expression studies performed with tobacco and rapeseed protoplasts, indicating that the LTR sequences are recognized in heterologous species. Our results also showed that Tntl LTR-promoted GUS expression in transgenic Arabidopsis is strongly regulated, and that, in contrast to tobacco, hormonal activation plays a significant role in the expression of the Tntl LTR in Arabidopsis. LTR sequences were shown to be more effective than the CaMV 35S enhancer region in transient expression studies performed with tobacco or rapessed protoplasts; and substitution of the LTR sequences upstream from the major transcriptional start with the CaMV 35S enhancer region gave high levels of expression in transgenic tobacco and Arabidopsis leaves, suggesting that a Tntl element with similar substitutions in its 5′ LTR might be suited for gene-tagging experiments in heterologous species.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 26 (1994), S. 1217-1222 
    ISSN: 1573-5028
    Keywords: Brassica napus ; pistil ; stigma ; cDNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A partial cDNA clone, Pis 63, corresponding to a mRNA highly expressed in Brassica napus pistils, was isolated by differential screening. PCR was used to complete the Pis 63 sequence (Pis 63-1) and to obtain the sequence of another related cDNA (Pis 63-2). Northern blot and in situ analyses demonstrated that these transcripts are expressed in the stigma throughout flower development. Pis 63-1 and Pis 63-2 display similarity to a cotton fibre cDNA clone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1573-5028
    Keywords: Brassica napus ; microspore embryogenesis ; napin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Brassica napus cv. Topas microspores can be diverted from pollen development toward haploid embryo formation in culture by subjecting them to a heat stress treatment. We show that this switch in developmental pathways is accompanied by the induction of high levels of napin seed storage protein gene expression. Changes in the plant growth or microspore culture conditions were not by themselves sufficient to induce napin gene expression. Specific members of the napin multigene family were cloned from a cDNA library prepared from microspores that had been induced to undergo embryogenesis. The majority of napin clones represented three members (BnmNAP2, BnmNAP3 and BnmNAP4) that, along with a previously isolated napin genomic clone (BngNAP1), constitute the highly conserved BnmNAP subfamily of napin genes. Both RNA gel blot analysis, using a subfamily-specific probe, and histochemical analysis of transgenic plants expressing a BngNAP1 promoter-β-glucuronidase gene fusion demonstrated that the BnmNAP subfamily is expressed in embryogenic microspores as well as during subsequent stages of microsporic embryo development.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1573-5028
    Keywords: acyl-CoA-binding protein ; Brassica napus ; diazepam-binding inhibitor protein ; linkage map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA encoding an acyl-CoA-binding protein (ACBP) homologue has been cloned from a λgt11 library made from mRNA isolated from developing seeds of oilseed rape (Brassica napus L.). The derived amino acid sequence reveals a protein 92 amino acids in length which is highly conserved when compared with ACBP sequences from yeast, cow, man and fruit fly. Southern blot analysis ofBrassica napus genomic DNA revealed the presence of 6 genes, 3 derived from theBrassica rapa parent and 3 fromBrassica oleracea. Northern blot analysis showed that ACBP genes are expressed strongly in developing embryo, flowers and cotyledons of seedlings and to a lesser extent in leaves and roots.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1432-203X
    Keywords: Trifoliate orange ; Epicotyl segment ; Agrobacterium ; Transformation ; rolC promoter ; β-glucuronidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A simple and efficient gene transfer system of trifoliate orange (Poncirus trifoliata Raf.) was developed using epicotyl segments. The segments were infected with Agrobacterium harboring the binary vector pBI121 or pBI101-O12-p1. Both vectors contained the neomycin phosphotransferase II (NPTII) and the β-glucuronidase (GUS) genes. In the plasmid pBI101-O12-p1, the GUS gene was directed to the promoter region of ORF12 (rolC) of the Ri plasmid. On a selection medium containing 100 or 200 μg/ml kanamycin, adventitious shoots were formed from 21.7–44.6% of the segments. Histochemical GUS assay showed that 55.4–87.7% of the shoots expressed the GUS gene. The stable integration of this gene was also confirmed by polymerase chain reaction (PCR) analysis and by Southern blot analysis. When the pBI101-O12-p1 plasmid was used, the GUS activity was found to be located in phloem cells of leaf, stem and root. More than 100 transformed plants were obtained using this method within 2–3 months.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    ISSN: 1432-203X
    Keywords: Agrobacterium rhizogenes ; Brassica napus ; glutamine synthetase ; phosphinothricin ; rape ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Hairy roots of Brassica napus (rape cv. Giant) have been produced that contain the cytosolic glutamine synthetase (GS) gene from Glycine max (soybean). Leaf explants were cocultivated with Agrobacterium rhizogenes strain A4T harbouring the binary vector pLN16. This vector was constructed by inserting a soybean cytosolic GS cDNA into the multiple cloning site of pGA643, placing it under the control of the CaMV promoter. In addition, the T-DNA region of pLN16 contained a NPTII gene for selection of transformed cells. Transgenic hairy roots grew prolifically on hormone-free media containing a selective level of kanamycin. Southern and northern analyses confirmed the presence of soybean GS DNA and transcripts, respectively. These transformed hairy roots also have a greater abundance of the GS polypeptide, approximately 3–6 fold greater GS activity and lower levels of endogenous ammonia. Hairy roots provide a useful system for studying responses to phosphinothricin (PPT). Hairy roots grown in media containing PPT had lower GS activity, greater ammonia accumulation and slower growth than controls. The presence of the soybean GS gene in the hairy roots reduced these PPT-induced effects and resulted in higher GS activity, lower ammonia levels and faster growth than in PPT-treated controls. Greater tolerance of PPT was also seen in shoots regenerated from the hairy roots displaying elevated levels of GS activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 87 (1994), S. 697-704 
    ISSN: 1432-2242
    Keywords: Brassica napus ; Cultivar identification ; RAPDs ; Rapeseed ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract RAPDs (Randomly Amplified Polymorphic DNAs) were used to discriminate among 23 cultivars of oilseed rape (Brassica napus) selected from several breeding programs. A set of 100 random sequence 10-mer primers were tested, of which 70 produced bands and 22 showed evidence of polymorphism. A selection of six primers produced 23 polymorphic bands of between 300 to 2200 base pairs in size, sufficient to distinguish between the cultivars. An analysis of seed of five cultivars obtained from four different sites showed stability of banding pattern over source of seed. The analysis was repeated using four different thermocyclers, each of which produced the same band pattern. UPGMA cluster analysis indicates that the relationships among some of the cultivars is closer for those from the same breeding program than for those from different programs. The results of this study show that RAPDs can be used as a method of identification for oilseed rape cultivars.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 88 (1994), S. 123-128 
    ISSN: 1432-2242
    Keywords: Brassica napus ; RFLP markers ; RAPD markers ; Genetic distance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract RFLP and RAPD markers were evaluated and compared for their ability to determine genetic relationships in a set of three B. napus breeding lines. Using a total of 50 RFLP and 92 RAPD markers, the relatedness between the lines was determined. In total, the RFLP and the RAPD analysis revealed more than 500 and 400 bands, respectively. The relative frequencies of loci with allele differences were estimated from the band data. The RFLP and RAPD marker sets detected very similar relationships among the three lines, consistent with known pedigree data. Bootstrap analyses showed that the use of approximately 30 probes or primers would have been sufficient to achieve these relationships. This indicates that RAPD markers have the same resolving power as RFLP markers when used on exactly the same set of B. napus genotypes. Since RAPD markers are easier and quicker to use, these markers may be preferred in applications where the relationships between closely-related breeding lines are of interest. The use of RAPD markers in fingerprinting applications may, however, not be warranted, and this is discussed in relation to the reliability of RAPD markers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 88 (1994), S. 433-440 
    ISSN: 1432-2242
    Keywords: Agrobacterium ; Transformation ; Gene expression ; Petunia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transgenic petunia (Petunia hybrida Vilm.) plants were obtained from Agrobacterium-mediated shoot apex transformation. Studies at the phenotypic as well as molecular level established both the presence of the NPT II (neomycin phosphotransferase II) and GUS (β-glucuronidase) genes and their level of activity. Twenty-nine primary transformed plants showed varying patterns of phenotype expression of both genes. NPT II and GUS expression in 7 primary plants over a 4-month interval showed varying levels of gene expression within and among individual plants. All primary transgenic plants were self-pollinated and backcrossed to establish the inheritance patterns of both genes. Mendelian and non-Mendelian inheritance patterns for both genes were observed. Analysis of the progeny showed poor transmission of the foreign genes through the pollen especially when two or more bands were present in the Southern hybridization. Most plants whose progeny segregated in Mendelian ratios for either the NPT II or GUS gene had just one copy of the gene. In this study where both foreign genes were examined in both self and test crosses, no transgenic plant showed Mendelian patterns of inheritance for both foreign traits.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 88 (1994), S. 662-668 
    ISSN: 1432-2242
    Keywords: Oilseed rape ; Brassica napus ; Restriction fragment length polymorphism ; Genetic diversity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Oilseed rape (Brassica napus) is an important oilseed crop worldwide. Cultivars have been developed for many growing regions, however little is known about genetic diversity inB. napus germ plasm. The purpose of the research presented here was to study the genetic diversity and relationships ofB. napus accessions using restriction fragment length polymorphisms (RFLPs). Eighty threeB. napus accessions were screened using 43 genomic DNA clones which revealed 161 polymorphic fragments. Each accession was uniquely identified by the markers with the exception of the near-isogenic cvs ‘Triton’ and ‘Tower’. The RFLP data were analyzed by cluster analysis of similarity coefficients and by principal component analysis. Overall, there were three major groups of cultivars. The first group included only spring accessions, the second mostly winter accessions and the third, rutabagas and oilseed rape accessions from China and Japan. These results indicate that withinB. napus, winter and spring cultivars represent genetically distinct groups. The grouping of accessions by cluster analysis was generally consistent with known pedigrees. This consistency included the grouping of lines derived both by backcrossing or self-pollination with their parents.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    ISSN: 1432-2242
    Keywords: Agrobacterium ; Iodoacetamide Nicotiana protoplast fusion ; Nitrosomethyl urea Rhodamine 6G ; X-irradiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An effective selection system preceded by double inactivation of parental protoplasts was used to transfer Nicotiana suaveolens Leh. cytoplasmic male sterility into a commercial tobacco (N. tabacum L.) breeding line. Mesophyll protoplasts from transformed plants of N. tabacum cultivar WZ2-3-1-1 possessing a neomycin phosphotransferase II gene were used as the nuclear donors, while those isolated from N. suaveolens plants carrying a chloroplast mutation for resistance to spectinomycin, induced using nitrosomethyl urea, were the cytoplasm donors in somatic cybridizations. Prior to fusion, nuclear donor protoplasts were inactivated with iodoacetamide or rhodamine 6G, while those of the cytoplasm donor were inactivated by X-irradiation. The resultant microcalli were cultured on a shoot regeneration medium containing both kanamycin and spectinomycin to select cybrids. Only regenerants that had typical characteristics of the N. tabacum cultivar were selected for transfer to the glasshouse. Four putative cytoplasmic male-sterile (CMS) plants, out of a total of 44 regenerated plants transferred to the glasshouse, were obtained. Intraspecific somatic transfers of the CMS trait between N. tabacum cultivars with distinctlydifferent morphologies using single inactivation and nonselective shoot regeneration medium were demonstrated. The implications of the results for practical tobacco breeding as a means of circumventing lengthy backcrossing procedures are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1432-2242
    Keywords: Brassica napus ; Raphanus sativus ; Ogura cytoplasmic male-sterility restorer gene ; Bulked segregant analysis ; RAPD markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bulked segregant analysis was employed to identify random amplified polymorphic DNA (RAPD) markers linked to the restorer gene (Rfo) used in theOgura radish cytoplasmic male sterility of rapeseed. A total of 138 arbitrary 10-mer oligonucleotide primers were screened on the DNA of three pairs of bulks, each bulk corresponding to homozygous restored and male sterile plants of three segregating populations. Six primers produced repeatable polymorphisms between paired bulks. DNA from individual plants of each bulk was then used as a template for amplification with these six primers. DNA polymorphisms generated by four of these primers were found to be completely linked to the restorer gene with the polymorphic DNA fragments being associated either with the fertility restorer allele or with the sterility maintainer allele. Pairwise cross-hybridization demonstrated that the four polymorphic DNA fragments did not share any homology. Southern hybridization of labelled RAPD fragments on digested genomic DNA from the same three pairs of bulks revealed fragments specific to either the male sterile bulks or to the restored bulks and a few fragments common to all bulks, indicating that the amplified sequences are low copy. The four RAPD fragments that were completely linked to the restorer locus have been cloned and sequenced to develop sequence characterized amplified regions (SCARs). This will facilitate the construction of restorer lines used in breeding programs and is the first step towards map-based cloning of the fertility restorer allele.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1432-2242
    Keywords: Polymerase chain reaction ; Random amplified polymorphic DNA ; Self-incompatibility ; Brassica campestris ; Brassica napus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have developed an efficient PCR-based system that uses RAPD markers for the certification of F1 hybrids of canola. These markers were selected by screening five parental lines used in three crosses X, Y and Z with 131, 131 and 322 primers respectively. Stable DNA fragments that were homozygous and specific to the male inbreds were used to certify F1 hybrid populations. The hybrid production system was based on self-incompatibility (SI) alleles that prevent self-pollination of the female parent. The efficiency of two S-alleles was compared under both field and greenhouse conditions. The percentage of hybridity was estimated in different F1 populations. We found a significant difference between the two alleles for their efficiency in controlling selfing; both alleles were stable under greenhouse conditions, one allele appeared less reliable under field conditions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 89 (1994), S. 577-582 
    ISSN: 1432-2242
    Keywords: Wheat ; Transformation ; Agrobacterium ; Electroporation ; Polyethylene glycol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A procedure for culturing protoplasts from slowly growing embryogenic calli of wheat was developed. The procedure was dependent on the ability to isolate large numbers of culturable protoplasts from slowly growing embryogenic callus. Approximately 68% of the isolated protoplasts divided, and 22% formed colonies; of the latter, 67% continued to proliferate. Plating efficiency was reduced when protoplasts were transformed by polythylene glycol, electroporation, and/or Agrobacterium. Intact cells were also directly transformed by electroporation. Direct electroporation of the Agrobacterium binary vector into intact cells resulted in a significant increase of GUS activity over the control.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 89 (1994), S. 615-621 
    ISSN: 1432-2242
    Keywords: Brassica napus ; Doubled haploid ; Linkage map ; Restriction fragment length polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The combined use of doubled haploid lines and molecular markers can provide new genetic information for use in breeding programs. An F1-derived doubled haploid (DH) population of Brassica napus obtained from a cross between an annual canola cultivar (‘Stellar’) and a biennial rapeseed (‘Major’) was used to construct a linkage map of 132 restriction fragment length polymorphism loci. The marker loci were arranged into 22 linkage groups and six pairs of linked loci covering 1016 cM. The DH map was compared to a partial map constructed with a common set of markers for an F2 population derived from the same F1 plant, and the overall maps were not significantly different. Comparisons of maps in Brassica species suggest that less recombination occurs in B. napus (n = 19) than expected from the combined map distances of the two hypothesized diploid progenitors, B. oleracea (n = 9) and B. rapa (n=10). A high percentage (32%) of segregating marker loci were duplicated in the DH map, and conserved linkage arrangements of some duplicated loci indicated possible intergenome homoeology in the amphidiploid or intragenome duplications from the diploid progenitors. Deviation from Mendelian segregation ratios (P 〈 0.05) was observed for 30% of the marker loci in the DH population and for 24% in the F2 population. Deviation towards each parent occurred at equal frequencies in both populations and marker loci that showed deviation clustered in specific linkage groups. The DH lines and molecular marker map generated for this study can be used to map loci for agronomic traits segregating in this population.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 88 (1994), S. 321-323 
    ISSN: 1432-2242
    Keywords: Brassica napus ; Inbreeding ; Inbreeding depression ; Line variation ; Competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rapeseed plants, of the summer annual variety Topas, that had been selfed twice consecutively were compared to outcrossed half-sibs for inbreeding depression in a rapeseed population at mating equilibrium. The effect of dominance-suppression competition was included in the effect of inbreeding. Both female-and male-fitness characters showed significant inbreeding depression. Biomass decreased 17% with inbreeding and was highly correlated with seed weight. The total number of flowers decreased 15% with inbreeding. There was a significant effect of lines. The possible importance of experimental design in studies that estimate inbreeding depression is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 89 (1994), S. 540-544 
    ISSN: 1432-2242
    Keywords: Brassica napus ; Crossability ; Cytogenetics ; Intergeneric hybridization ; Sinapis pubescens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cytological possibility of gene transfer from Sinapis pubescens to Brassica napus was investigated. Intergeneric hybrids between Brassica napus (2n = 38) and Sinapis pubescens (2n = 18) were produced through ovary culture. The F1 hybrids were dihaploid and the chromosome configurations were (0–1) III + (2–11) II + (5–24) I . One F2 plant with 38 chromosomes was obtained from open pollination of the F1 hybrid. Thirty-one seeds were obtained from the backcross of the F2 plant with B. napus. Five out of seven plants had 38 chromosomes, and the pollen stainability ranged from 0% to 81.4%. In the B2 plants obtained from the backcross of B1 plants with B. napus, 66.7% of the plants examined had 38 chromosomes. S. pubescens may become a gene source for the improvement of B. napus.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 1573-9368
    Keywords: Agrobacterium ; mutagenesis ; Nicotiana plumbaginifolia ; nitrate reductase ; ploidy ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transformation frequencies were determined for 1n, 2n, and 4n Nicotiana plumbaginifolia protoplast cultures inAgrobacterium-mediated gene transfer experiments. An unexpected large drop (50%) in plating efficiencies was observed in the non-selected (control) 1n populations after transformation treatment with virulent strains. This effect was not observed in the 2n or 4n cultures or in the 1n cultures when treated with avirulent bacteria. The mortality was disproportionally high and could not be explained by the low (0.1–0.5%) transformation efficiency in the 1n population, indicating mutagenesis of the cell populations independently from the T-DNA insertions. Mutagenesis was also indicated in gene tagging experiments where nitrate reductase-deficient (NR−) mutants were selected from haploidNicotiana plumbaginifolia protoplasts, as well as from leaf disc cultures or protoplasts of diploid plants that were heterozygotic for a mutation either in the NR apoenzyme gene (nia/wt) or one of the molybdenum-containing cofactor genes (cnxA/wt), afterAgrobacterium co-cultivation. The chlorate-resistant isolates were tested for the T-DNA-specific kanamycin resistance trait only after NR-deficiency had been established. Thirty-nine independent NR-deficient mutants were analysed further by Southern blot hybridization. There was no indication of integrated T-DNA sequences in the mutated NR genes, despite the fact that NR-deficient cells were found more frequently in cell populations which became transformed during the treatment than in the populations which did not. These observations suggest that transformation-competent cells undergo mutagenesis during theAgrobacterium gene transfer process not only as a result of stable integration events, but also through accompanying events that do not result in major changes in the mutated loci. The nature of these changes at the molecular level remains to be elucidated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Transgenic research 3 (1994), S. 263-278 
    ISSN: 1573-9368
    Keywords: Brassica napus ; oilseed rape ; transgenic plants ; interspecific hybridization ; gene transfer ; risk assessment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Before novel transgenic plant genotypes are grown outside containment facilities and evaluated under field conditions, it is necessary to complete a risk assessment to consider the possible consequences of that release. An important aspect of risk assessment is to consider the likelihood and consequences of the transgene being transferred by cross-pollination to related species, including other crops, weeds and ruderal populations. The purpose of this report is to review the literature to assess the ease with whichBrassica napus can hybridize with related species. The evidence for hybridization is considered at three levels: a) by open pollination, b) by hand pollination and c) by the use ofin vitro ovule and embryo rescue techniques; and also examines the fertility and vigour of the F1, F2 and backcross generations. Four species are reported to hybridize withB. napus by open pollination:B. rapa andB. juncea using fully fertile parents; andB. adpressa andR. raphanistrum using a male-sterileB. napus parent. Seventeen species are reported to form hybrids (including the four species above) withB. napus when pollination is carried out manually. At least 12 of these species were unable to form F2 progeny, and eight were unable to produce progeny when the F1 was backcrossed to one of the parental species. Many factors will influence the success of hybridization under field conditions, including: distance between the parents, synchrony of flowering, method of pollen spread, specific parental genotypes used, direction of the cross and the environmental conditions. Even where there is a possibility of hybridization betweenB. napus and a related species growing in the vicinity of a release, poor vigour and high sterility in the hybrids will generally mean that hybrids and their progeny will not survive in either an agricultural or natural habitat.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 1573-9368
    Keywords: Agrobacterium ; β-glucuronidase ; cytoenzymology ; reporter gene ; transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract For several models expressing theuidA orgus reporter gene with or without a presequence for mitochondrial targeting, we have demonstrated that the compartmentation of β-glucuronidase (E.C. 3.2.1.31) activity was not in agreement within situ localization of the diX-indigo microcrystals generated by the cytoenzymological GUS assay. These crystals were generally associated with the various cytomembranes and lipid inclusions. Experiments with purified β-glucuronidase or withgus-expressing bacteria incubated with 5-bromo-4-chloro-3-indolyl-β-d-glucuronide and maize oil-phosphate buffer emulsion indicated that the intermediate products resulting from the GUS assay actively diffused and crystallized preferentially in association with lipids, sometimes far from the site of enzyme activity. This phenomenon could not be suppressed by the addition of potassium ferricyanide in the incubation medium. These findings are discussed with regard to previously reported biochemical and histochemical data on animal tissues, and focus on the necessity for caution in studies of tissue-specific gene expression using the GUS assay, particularly for lipid-rich plant models.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 183 (1994), S. 67-76 
    ISSN: 1615-6102
    Keywords: Actin microfilaments ; Brassica napus ; Cytochalasin D ; Pollen development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The organization of actin microfilaments (MFs) was studied during pollen development ofBrassica napus cv. Topas. Cells were prepared using three techniques and double labelled for fluorescence microscopy with rhodamine-labelled phalloidin for MFs and Hoechst 33258 for DNA. Microfilaments are present at all stages of pollen development with the exception of tricellular pollen just prior to anthesis. Unicellular microspores contain MFs which radiate from the surface of the nuclear envelope into the cytoplasm. During mitosis MFs form a network partially surrounding the mitotic apparatus and extend into the cytoplasm. Both cytoplasmic and phragmoplast-associated MFs are present during cytokinesis. Nuclear associated-, cytoplasmic, and randomly oriented cortical MFs appear in the vegetative cell of the bicellular microspore. Cortical MFs in the vegetative cell organize into parallel MF bundles (MFBs) aligned transverse to the furrows. The MFBs disappear prior to microspore elongation. At anthesis MFs are restricted to the cortical areas subjacent to the furrows of the vegetative cell. The use of cytochalasin D to disrupt MF function resulted in: (1) displacement of the acentric nucleus in the unicellular microspore; (2) displacement of the spindle apparatus in the mitotic cell; (3) symmetrical growth of the bicellular microspore rather than elongation and (4) inhibition of pollen tube germination in the mature pollen grain. This suggests that MFs play an important role in anchoring the nucleus in the unicellular microspore as well as the spindle apparatus during microspore mitosis, in microspore shape determination and in pollen tube germination.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 244 (1994), S. 367-373 
    ISSN: 1617-4623
    Keywords: Agrobacterium ; Nopaline ; Repressor Activator ; LysR family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The NocR protein of Agrobacterium tumefaciens was found to regulate expression of the divergently transcribed nocB and nocR genes of the pTiT37 nopaline catabolism (noc) region. Experiments using the firefly luciferase (luc) gene as reporter demonstrated that NocR represses and activates transcription from the nocB promoter in the absence and presence of nopaline, respectively. NocR also negatively autoregulates its own synthesis irrespective of the presence of nopaline. Regulation of expression of both nocB and nocR is mediated by binding of the NocR protein to the nocR promoter. A 12 by symmetrical sequence, which lies 3 by downstream of the −10 hexamer of the nocR promoter, was confirmed to be essential for binding of the NocR protein. Functional localization of the nocB and nocR promoters verified that they do not overlap at all, and that the interrupted dyad, at which NocR binds, is 137 by upstream of the regulated nocB promoter. The in vivo and in vitro results described here and those published previously suggest that a novel type of regulatory mechanism, which may involve changes in DNA topology, controls gene expression in the noc operon of pTiT37.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 245 (1994), S. 493-505 
    ISSN: 1617-4623
    Keywords: Agrobacterium ; Bacterial evolution ; Nopaline strains ; Ti plasmids ; Grapevine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Ti plasmid of the Agrobacterium vitis nopaline-type strain AB4 was subcloned and mapped. Several regions of the 157 kb Ti plasmid are similar or identical to parts of the A. vitis octopine/cucumopine (o/c)-type Ti plasmids, and other regions are homologous to the nopaline-type Ti plasmid pTiC58. The T-DNA of pTiAB4 is a chimaeric structure of recent origin: the left part is 99.2% homologous to the left part of the TA-DNA of the o/c-type Ti plasmids, while the right part is 97.1 % homologous to the right part of an unusual nopaline T-DNA recently identified in strain 82.139, a biotype Il strain from wild cherry. The 3′ non-coding regions of the ipt genes from pTiAB4 and pTi82.139 are different from those of other ipt genes and contain a 62 by fragment derived from the coding sequence of an ipt gene of unknown origin. A comparison of different ipt gene sequences indicates that the corresponding 62 by sequence within the coding region of the AB4 ipt gene has been modified during the course of its evolution, apparently by sequence transfer from the 62 by sequence in the 3′ non-coding region. In pTi82.139 the original coding region of the ipt gene has remained largely unmodified. The pTiAB4 6b gene differs from its pTi82.139 counterpart by the lack of a 12 by repeat in the 3′ part of the coding sequence. This leads to the loss of four glutamic acid residues from a series of ten. In spite of these differences, the ipt and 6b genes of pTiAB4 are functional. Our results provide new insight into the evolution of Agrobacterium Ti plasmids and confirm the remarkable plasticity of these genetic elements. Possible implications for the study of bacterial phylogeny are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 159 (1994), S. 171-178 
    ISSN: 1573-5036
    Keywords: Agrobacterium ; Gigaspora margarita ; Glomus intraradix ; PCR ; mycorrhizae ; rDNA gene ; root organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The symbiosis between vesicular-arbuscular mycorrhizal (VAM) fungi and host plants develops after successful interactions between both partners. These interactions probably involve signal molecules produced by the host plant, by the fungi, or by both. So far the biotrophic status of VAM fungi has hampered the understanding of the processes regulating their physiology. However, among different methods for co-cultivating VAM fungi, root organ cultures (ROC) appear to be a useful technique for studying VAM development. This system has been useful in defining the nutritional requirements of VAM fungi in the precolonization stage and in obtaining axenic fungal material in various developmental stages. The work discussed here focuses on the application of Polymerase Chain Reaction (PCR) technology and the potential of promoting hyphal growth in the absence of the plant. These techniques are being used to study VAM fungi in two main areas. The first concerns the determination of the DNA sequences coding for the SSU ribosomal RNA of two VAM fungi. This approach has allowed the design of specific primers for the rapid identification and quantification of VAM fungi. The second area of research concerns the potential use of PCR technology to study selective expression of specific genes during fungal spore development in defined in vitro conditions. The achievement of this future prospect depends on the ability to prepare PCR-based cDNA libraries from small amounts of fungal material after stimulation of hyphal growth with CO2 and plant flavonols.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 1573-5044
    Keywords: Agrobacterium ; Atropa belladonna ; double transformation ; phytohormone content ; tropane alkaloids ; viviparous leaves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Hairy root cultures of Atropa belladonna L. were established by infection either with Agrobacterium rhizogenes ATCC 15834 or MAFF 03-01724, and transgenic plants were obtained from both hairy root cultures. Doubly transformed roots were induced by re-infection of the leaf segments of transgenic Atropa belladonna plants (A. rhizogenes 15834) with MAFF 03-01724. Shoots and viviparous leaves were regenerated from the doubly transformed roots. The genetic transformation was determined by the opine assay (agropine, mannopine and/or mikimopine) and polymerase chain reaction. Physiological changes and tropane alkaloid biosynthesis in the hairy roots (singly and doubly transformed) were investigated. The alkaloid content in the doubly transformed root strain was intermediate as compared to the root strains which were singly transformed. On the other hand endogenous IAA levels in doubly transformed roots were significantly decreased compared to both singly transformed roots.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 42
    ISSN: 1573-5060
    Keywords: Brassica napus ; light reflectance ; seed colour ; NIR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Improved oil, protein and fibre contents are associated with light seed colour in rapeseed but the lack of reliable and efficient methods to measure seed colour has hindered breeding efforts for this trait. The feasibility of using light reflectance to assess seed colour in Brassica napus was examined using scanning light reflectance spectrophotometry and near infrared reflectance (NIR). Light reflectance by seed samples from 30 doubled haploid (DH) lines segregating for seed colour increased as the wavelength of the illuminating light in the scanning spectrophotometer increased between 550 and 650 nm. The largest reflectance values were measured for the yellow seed samples; the brown seed samples were intermediate and the black seed samples had the lowest reflectance values. The areas under the reflectance curves were used to transform the spectra to single values. Average light reflectance area values for the seed colour classes were significantly different from each other. The DHs and their corresponding light reflectance area values were also used to calibrate a NIR analyzer modified with 670 and 710 nm filters. The best calibration curve used three wavelengths (670, 2190 and 2208 nm) and had a multiple correlation coefficient of 0.987. Light reflectance area values determined with the calibrated NIR analyzer for 30 randomly selected breeding lines could be used to categorize the colour of the seed samples with no discrepancies between the visual and instrument classifications. The results indicate that NIR can be used to assess seed colour in rapeseed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 43
    ISSN: 1573-5087
    Keywords: abscisic acid ; 1-aminocyclopropane-1-carboxylic acid ; BAS 111..W ; Brassica napus ; cytokinins ; oilseed rape ; pod ; senescence ; triazole growth retardant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Foliar treatment of oilseed rape plants (Brassica napus L.ssp. napus cv. Linetta) with the growth retardant BAS 111..W at the 5th leaf stage delayed pod senescence during early maturation. Changes of immunoreactive cytokinin- and abscisic acid (ABA)- like substances and of the ethylene precursor 1-aminocyclo-propane-1-carboxylic acid (ACC) and its malonyl-conjugate (MACC) were determined in intact whole pods. When compared with control plants, higher levels of total chlorophyll correlated with four-fold and three-fold increases of trans-zeatin riboside- and dihydrozeatin riboside-type cytokinins, respectively, in the pods of plants treated with 0.25 mg BAS 111..W per plant. Isopentenyladenosine-type cytokinins and ACC and MACC contents remained virtually unchanged, whereas ABA levels dropped considerably below those of controls (60% reduction). However, when analysed at late pod maturity, BAS 111..W treatment no longer affected the total chlorophyll content, or the levels of cytokinins, ABA, ACC and MACC. We hypothesize that the retardant-induced changes in the hormonal status of the pods, favouring the senescence-delaying cytokinins as opposed to abscisic acid, could contribute to the developmental delay.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 1573-5060
    Keywords: Brassica napus ; heterosis ; hybrid breeding ; oilseed rape ; self-incompatibility ; pollination control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Self-incompatibility was shown to be an effective method of pollination control in spring rapeseed (B. napus L. ssp. oleifera (Metzg.)) by comparing the yield of a Westar-Topas syn-1 produced by crossing two SI lines with the yield of the corresponding syn-1 produced by hand pollination. Although the trial showed high-parent heterosis in the syn-1s, there was insufficient replication to determine the level of heterosis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1573-5060
    Keywords: Brassica napus ; microspore culture ; colchicine treatment ; chromosome doubling ; DH-breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The effect of colchicine on isolated microspore cultures of Brassica napus was evaluated in order to combine a positive effect of colchicine on the induction of embryogenesis with the possibility to induce chromosome doubling at an early developmental stage, thus avoiding the production of haploid or chimeric plants. Colchicine was added to the culture medium immediately after isolation of B. napus microspores. The cultures were incubated from 6 to 72 h with various concentrations of colchicine. Samples were taken from the regenerating embryoids after 6 weeks for ploidy determination by flow-cytometry. The highest diploidization rate was obtained after a 24 h treatment of microspores with 50 mg/l colchicine, leading to 80–90% diploid embroids. A concentration of 100 mg/l colchicine applied for the same duration resulted in a lower diploidization rate (76–80%). Treatment durations of 6 h were not long enough to induce a high rate of diploidization, whereas the application of 10 mg/l for 72 h was also very effective. A sample of the plants regenerated from the colchicine treated microspores was transferred to the greenhouse. The plants looked similar to normal diploid rapeseed plants and showed reasonable pod and seed set. Thus, an additional generation for seed increase in the greenhouse is rendered unnecessary. The advantage of applying a minimum volume of colchicine under controlled in vitro conditions means a considerable saving of time and labour in DH-breeding programs.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 1573-9368
    Keywords: gene flow ; pollination ; bumblebees ; oilseed rape ; Brassica napus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Genetically modified plants containing selectable markers offer a unique opportunity for pollination biologists to investigate some of the major, but intractable questions about paternity distributions and their causes. Here, a method is reported that uses transgenic plants to enable the quantification of the outcrossed fertilizations that result from a single pollinator visit. Gene flow mediated by worker bumblebees (Bombus terrestris) was studied among plants of oilseed rape (Brassica napus L. cv. Westar) where transgenic paternity in seeds of a non-transgenic plant was manifested as herbicide resistance. Overall, 91% of the resistant seeds resulted from the first four flowers that were visited after the bumblebee left the transgenic plant, and none was found beyond the 14th successively visited flower. The possibilities for developing the method to address various questions in pollination biology are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Sexual plant reproduction 6 (1993), S. 52-56 
    ISSN: 1432-2145
    Keywords: In vitro culture ; Brassica napus ; Pollination ; Pod ; Seed
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A technique for cultivating isolated flowers of Brassica napus has been developed. Flowers were harvested at anthesis, the surface of their peduncles was then sterilized and they were cultivated in a hormonefree medium. We used an MS medium supplemented with 3% sucrose as a source of organic carbon. From our experiments, it was concluded that no exogenous growth regulator is required to ensure normal growth and development in vitro. The flowers, and thereafter the pods, can be kept in culture until seed maturity. After 30 days, seed development resulted in three types of seeds: (1) normal, (2) milky and (3) aborted. The results show that the number of seeds per pod was not dependent on the order of flowers on the raceme (except the first 10 flowers and flowers above row 50). Our study supports the validity of this model as an easy tool for studying pollination and early seed development.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell reports 12 (1993), S. 180-183 
    ISSN: 1432-203X
    Keywords: Peas ; Seed ; Transformation ; Agrobacterium ; Meristems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The lateral cotyledonary meristems present in germinating seed were inoculated with a non-oncogenic strain of A. tumefaciens carrying a gene conferring kanamycin resistance as a selectable marker and a β-glucuronidase sequence as a reporter gene. Kanamycin resistant plants were derived from the meristems and shown to be transformed on the basis of Southern blots, polymerase chain reaction analysis and tests for β-glucuronidase activity. The plants were fertile and tests of their progeny confirmed the transmission of integrated sequences through a sexual generation. This transformation method has the merit of an unlimited supply of material for inoculation and a relatively short time scale from inoculation to the production of rooted plants.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 1573-5028
    Keywords: Agrobacterium ; growth retardants ; plant hormones ; Ri plasmid ; transgenic tobacco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The rolA gene of the TL-DNA of Agrobacterium rhizogenes Ri-plasmid plays a major role in establishing the hairy root syndrome in transgenic plants. Transgenic tobacco plants (Nicotiana tabacum L.) expressing constitutively the rolA gene under the transcriptional control of the 35S RNA promoter show pronounced phenotypical alterations. P35S-rolA transgenic tobacco plants are characterized by stunted growth, dark green wrinkled leaves with an altered length-to-width ratio, condensed inflorescences, retarded onset of flowering, a reduced number of flowers and shortened styles. To investigate whether the pleiotropic alterations of growth and development are linked to an altered hormonal status we have compared the immunoreactive content of indole-3-acetic acid, cytokinins, abscisic acid, gibberellin and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) of seedlings and different tissues of P35S-rolA transgenic plants, transgenic plants expressing the rolA gene under control of its own phloem-specific promoter and wild-type plants. Multiple tissue-specific alterations of phytohormone concentrations are the consequence of rolA gene activity. Changes of phytohormonal content can explain part of the rolA-induced phenotypic alterations. Most strikingly, in young and fully developed leaves of rolA and P35S-rolA transgenic clones a 40–60% reduction of immunoreactive gibberellin A1 was found, as compared to wild-type leaves. Treatment of wild-type tobacco plants with inhibitors of gibberellin biosynthesis phenotypic alterations similar to those of rolA transgenic plants. This suggests that the reduction of gibberellic acid content is indirectly but causally involved in rolA-induced alterations of stem elongation and planar leaf blade growth.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 1573-5028
    Keywords: active site ; β-glycosidases ; Brassica napus ; glucosinolates ; myrosinase ; thioglucoside ; glucohydrolase (EC 3.2.3.1)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Myrosinase isoenzymes are known to be encoded by two different families of genes denoted MA and MB. Nucleotide sequence analysis of a Brassica napus genomic clone containing a gene for myrosinase revealed it to be a pseudogene of the MA family. The gene spans more than 5 kb and contains at least 12 exons. The exon sequence of the gene is highly similar to myrosinase cDNA sequences. However, the gene displays three potential or actual pseudogene characters. Southern blot analysis using probes from the 3′ portions of the genomic and B. napus MA and MB cDNA clones showed that MA type myrosinases are encoded by approximately 4 genes, while MB type myrosinases are encoded by more than 10 genes in B. napus. Northern blots with mRNA from seeds and young leaves probed with the MA-and MB-specific probes showed that the MA and MB myrosinase gene families are differentially expressed. Myrosinases are highly similar to proteins of a β-glycosidase enzyme family comprising both β-glycosidases and phospho-β-glycosidases of as diverged species as archaebacteria, bacteria, mammals and plants. By homology to these β-glycosidases, putative active site residues in myrosinase are discussed on the basis of the similarity between β-glycosidases and cellulases.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1573-5028
    Keywords: Agrobacterium ; α-amylase promoter ; α-glucuronidase ; Oryza sativa ; potato suspension culture ; transgenic rice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have successfully transferred and expressed a reporter gene driven by an α-amylase promoter in a japonica type of rice (Oryza sativa L. cv. Tainung 62) using the Agrobacterium-mediated gene transfer system. Immature rice embryos (10–12 days after anthesis) were infected with an Agrobacterium strain carrying a plasmid containing chimeric genes of β-glucuronidase (uidA) and neomycin phosphotransferase (nptII). Co-incubation of potato suspension culture (PSC) with the Agrobacterium inoculum significantly improved the transformation efficiency of rice. The uidA and nptII genes, which are under the control of promoters of a rice α-amylase gene (αAmy8) and Agrobacterium nopaline synthase gene (nos), respectively, were both expressed in G418-resistant calli and transgenic plants. Integration of foreign genes into the genomes of transgenic plants was confirmed by Southern blot analysis. Histochemical localization of GUS activity in one transgenic plant (R0) revealed that the rice α-amylase promoter functions in all cell types of the mature leaves, stems, sheaths and roots, but not in the very young leaves. This transgenic plant grew more slowly and produced less seeds than the wild-type plant, but its R1 and R2 progenies grew normally and produced as much seeds as the wild-type plant. Inheritance of foreign genes to the progenies was also confirmed by Southern blot analysis. These data demonstrate successful gene transfer and sexual inheritance of the chimeric genes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1573-5028
    Keywords: Brassica napus ; deletion analysis ; napin ; promoter ; seed ; storage protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The promoter and upstream region of the Brassica napus 2S storage protein napA gene were studied to identify cis-acting sequences involved in developmental seed-specific expression. Fragments generated by successive deletions of the 5′ control region of the napA gene were fused to the reporter gene β-glucuronidase (GUS). These constructs were used to transform tobacco leaf discs. Analyses of GUS activities in mature seeds from the transformed plants indicated that there were both negatively and positively acting sequences in the napin gene promoter. Deletion of sequences between −1101 and −309 resulted in increased GUS activity. In contrast, deletion of sequences between −309 and −211 decreased the expression. The minimum sequence required for seed-specific expression was a 196 bp fragment between −152 and +44. Further 5′ deletion of the fragment to −126 abolished this activity. Sequence comparison showed that a G box-like sequence and two sequence motifs conserved between 2S storage protein genes are located between −148 to −120. Histochemical and fluorometric analysis of tobacco seeds showed that the spatial and developmental expression pattern was retained in the deletion fragments down to −152. However, the expression in tobacco seeds differed from the spatial and temporal expression in B. napus. In tobacco, the napA promoter directed GUS activity early in the endosperm before any visible activity could be seen in the heart-shaped embryo. Later, during the transition from heart to torpedo stages, the main expression of GUS was localized to the embryo. No significant GUS activity was found in either root or leaf.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 53
    ISSN: 1573-5028
    Keywords: Brassica napus ; pollen ; polygalacturonase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA clone, Sta 44-4, corresponding to a mRNA highly expressed in Brassica napus cv. Westar stamens, was isolated by differential screening and characterized. Northern blot and in situ analyses demonstrated that Sta 44-4 is synthesized in pollen beginning at the late uninucleate stage and reaches a maximum in trinucleate microspores. Sta 44-4 displayed significant sequence similarity to known pollen polygalacturonase genes. The B. napus pollen polygalacturonase gene was shown to be part of a small gene family and to display some polymorphism among different cultivars.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 1573-5028
    Keywords: cruciferin ; 12S globulin ; Brassica napus ; gene families ; transcription ; in situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The major storage protein in seeds of Brassica napus, the 12S globulin cruciferin, is composed of three different groups of subunits; cru1, cru2/3 and cru4. By using gene family-specific probes, we have investigated the accumulation, rate of synthesis and spatial distribution of transcripts corresponding to the different groups of cruciferin subunits in developing seeds. Cruciferin transcripts derived from different gene families accumulate coordinately to comparable amounts during seed development. The corresponding gene families are, however, transcribed at different rates. Investigation of the spatial distribution of transcripts corresponding to each group of cruciferin subunits in the developing seed by in situ hybridization, revealed that mRNAs of all three types accumulate in both axis and cotyledons. Transcripts derived from cru1 and cru4 gene families show a similar cell specificity and accumulate in a similar spatial manner during seed development. In contrast, mRNAs corresponding to the cru2/3 gene family are expressed with a partly different cell specificity and show a slightly different pattern of accumulation in the axis and cotyledons, with a delayed accumulation in epidermal cells. In the cotyledons, the initial accumulation of this type of cruciferin mRNAs is also distinguished from the two other types. The differences in cell specificity are seen in the root cap and in provascular cells, where mRNAs belonging to the cru2/3 family are absent.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 1573-5028
    Keywords: Brassica napus ; cold acclimation ; gene isolation ; human tumour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to identify genes involved in cold acclimation, we have constructed a cDNA library from Brassica napus (cv. Samouraï) cold-acclimated etiolated seedlings. By differential screening, a cDNA clone named pBnC24 (Brassica napus Cold), corresponding to a new cold-inducible plant gene, was isolated. Northern blot hybridizations using total RNA from acclimated and unacclimated seedlings confirmed that BnC24 represents a cold-regulated gene. In contrast with a number of cold-inducible plant genes, BnC24 does not seem to be responsive to abscisic acid (ABA). In addition, further screening of the ‘cold-acclimated’ cDNA library using pBnC24 cDNA as a probe, allowed the isolation of a second type of homologous cDNA. Sequence analysis showed that the two BnC24 genes encode basic 24 kDa proteins, which are highly hydrophilic and rich in alanine, lysine and arginine. The nucleotide and deduced amino acid sequences of these clones do not show any homology with other previously described cold-induced plants genes. However they have strong homology with a recently discovered human tumour gene, bbc1 (breast basic conserved), which seems to be highly conserved in eukaryotes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 23 (1993), S. 511-524 
    ISSN: 1573-5028
    Keywords: Brassicaceae ; Brassica napus ; glucosinolate ; myrosinase ; multigene family ; thioglucoside glucohydrolase (EC 3.2.3.1)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The glucosinolate hydrolyzing enzymes myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1) are encoded by a multigene family consisting of two subgroups. The first two nuclear genes representing each of these two subgroups of the new gene family, Myr1.Bn1 and Myr2.Bn1, from Brassica napus have been cloned and sequenced. Based on conserved regions in cDNA of three species, PCR (polymerase chain reaction) primers were made, and used to amplify and characterize the structure of the myrosinase genes in seven species of Brassiceae. Southern hybridization analysis of PCR products and genomic DNA indicates that myrosinase is encoded by at least 14 genes in B. napus, with similar numbers in the other species of Brassicaceae investigated. The Myr1 gene cloned from B. napus has a 19 amino acid signal peptide and consists of 11 exons of sizes ranging from 54 to 256 bp and 10 introns of sizes from 75 to 229 bp. The Myr2 gene has a 20 amino acid signal peptide and consists of 12 exons ranging in size from 35 to 262 bp and 11 introns of sizes from 81 to 131 bp. The exons from the two genes have 83% homology at the amino acid level. The intron-exon splice sites are of GT..AG consensus type. The signal peptides and presence of sites for N-linked glycosylation, suggest transport and glycosylation through the ER-Golgi complex. The differences between the two genes are discussed on the basis of their predicted expression at different developmental stages in the plant. Both genes show homology to a conserved motif representing the glycosyl hydrolase family of enzymes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 57
    ISSN: 1573-5028
    Keywords: acyl ; Brassica napus ; fatty acid synthesis ; plastidial location ; seed ; thioesterase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acyl-ACP thioesterases are involved in regulating chain termination of fatty acid biosynthesis in plant systems. Previously, acyl-ACP thioesterase purified from Brassica napus seed tissue has been shown to have a high preference for hydrolysing oleoyl-ACP. Here, oligonucleotides derived from B. napus oleoyl-ACP thioesterase protein sequence data have been used to isolate two acyl-ACP thioesterase clones from a B. napus embryo cDNA library. The two clones, pNL2 and pNL3, contain 1642 bp and 1523 bp respectively and differ in the length of their 3′ non-coding regions. Both cDNAs contain open reading frames of 366 amino acids which encode for 42 kDa polypeptides. Mature rape thioesterase has an apparent molecular weight of 38 kDa on SDS-PAGE and these cDNAs therefore encode for precursor forms of the enzyme. This latter finding is consistent with the expected plastidial location of fatty acid synthase enzymes. Northern blot analysis shows thioesterase mRNA size to be ca. 1.6 kb and for the thioesterase genes to be highly expressed in seed tissue coincident with the most active phase of storage lipid synthesis. There is some sequence heterogeneity between the two cDNA clones, but overall they are highly homologous sharing 95.7% identity at the DNA level and 98.4% identity at the amino acid level. Some sequence heterogeneity was also observed between the deduced and directly determined thioesterase protein sequences. Consistent with the observed sequence heterogeneity was Southern blot data showing B. napus thioesterase to be encoded by a small multi-gene family.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 58
    ISSN: 1432-2048
    Keywords: Agrobacterium ; Auxin ; Pisum (hairy roots) ; Root (auxin levels) ; Transformation (root)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Root segments of Pisum sativum L. were transformed by several strains of Agrobacterium rhizogenes. The resulting hairy roots, as well as apical segments from untransformed pea roots, were used to initiate root lines cultured in vitro. Levels of free IAA were quantified in the sub-cultured lines by gas-chromatography coupled to mass spectrometry, using selected ion monitoring. For most of the cultured untransformed and transformed root lines the IAA content was very small, compared with levels in untransformed intact primary roots. However, an agropine-type hairy root line (incited by strain 15834) contained significantly higher amounts of IAA. The peculiar phenotype of this root line (abundant production of calli) appears to be associated with an increased IAA level, as opposed to most of the hairy root lines, where the extensive secondary root proliferation associated with the hairy-root disease cannot be merely attributed to a markedly enhanced IAA content.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 1432-203X
    Keywords: Brassica juncea ; hypocotyl ; plant regeneration ; Agrobacterium ; genetic transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Twelve cultivars of Brassica juncea grown in different agroclimatic regions of the world were tested for their ability to regenerate in vitro from hypocotyl explants and, accordingly, were divided into three groups. One group of cultivars regenerated on MS medium supplemented with 2,4-D, BAP and with NAA, BAP combinations; another group regenerated only on MS with 2,4-D, BAP; and the third group showed very low regeneration on both of these combinations. Inclusion of silver nitrate in the medium was essential for high frequency of regeneration. In general, Indian cultivars were more responsive than the cultivars of CIS and Australian origin. Using the media optimal for regeneration and an Agrobacterium-based binary vector carrying hpt and gus-intron genes, conditions for genetic transformation of B. juncea hypocotyl explants were optimized. Transformation frequencies, identified by GUS staining at the initial stages of growth, were lower on MS medium with 2,4-D, BAP than on MS with NAA, BAP. Plants resistant to 20 μg/ml hygromycin were regenerated at a frequency of 11–36% from hypocotyl explants and were shown to be transformed by Southern blotting, GUS staining and progeny analysis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 60
    ISSN: 1432-203X
    Keywords: Brassica nigra ; Transformation ; Agrobacterium ; Direct gene transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genetic transformation systems have been established for Brassica nigra (cv. IC 257) by using an Agrobacterium binary vector as well as by direct DNA uptake of a plasmid vector. Both the type of vectors carried nptII gene and gus gene. For Agrobacterium mediated transformation, hypocotyl tissue explants were used, and up to 33% of the explants produced calli on selection medium. All of these expressed B-glucuronidase gene on histochemical staining. Protoplasts isolated from hypocotyl tissues of seedlings could be transformed with a plasmid vector by FEG mediated uptake of vector DNA. A number of fertile kanamycin resistant plants were obtained using both the methods, and their transformed nature was confirmed by Southern blot analysis and histochemical staining for GUS. Backcrossed and selfed progenies of these transformed plants showed the presence of npt and gus genes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 61
    ISSN: 1432-2242
    Keywords: Intergeneric crosses ; Somatic hybridization ; Sinapis alba ; Brassica napus ; Heterodera schachtii ; Nematode resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Sexual and somatic hybrid plants have been produced between Sinapis alba L. (white mustard) and Brassica napus L. (oil-seed rape), with the aim to transfer resistance to the beet cyst nematode Heterodera schachtii Schm. (BCN) from white mustard into the oil-seed rape gene pool. Only crosses between diploid accessions of S. alba (2n = 24, Sa1Sa1) as the pistillate parent and several B. napus accessions (2n = 38, AACC) yielded hybrid plants with 31 chromosomes. Crosses between tetraploid accessions of S. alba (2n = 48, Sa1Sa1Sa1Sa1) and B. napus were unsuccessful. Somatic hybrid plants were also obtained between a diploid accession of S. alba and B. napus. These hybrids were mitotically unstable, the number of chromosomes ranging from 56 to more than 90. Analysis of total DNA using a pea rDNA probe confirmed the hybrid nature of the sexual hybrids, whereas for the somatic hybrids a pattern identical to that of B. napus was obtained. Using chloroplast (cp) and mitochondrial (mt) DNA sequences, we found that all of the sexual F1 hybrids and somatic hybrids contained cpDNA and mtDNA of the S. alba parent. No recombinant mtDNA or cpDNA pattern was observed. Three BC1 plants were obtained when sexual hybrids were back-crossed with B. napus. Backcrossing of somatic hybrids with B. napus was not successful. Three sexual hybrids and one BC1 plant, the latter obtained from a cross between a sexual hybrid and B. napus, were found to show a high level of BCN resistance. The level of BCN resistance of the somatic hybrids was in general high, but varied between cuttings from the same plant. Results from cytological studies of chromosome association at meiotic metaphase I in the sexual hybrids suggest partial homology between chromosomes of the AC and Sa1 genomes and thus their potential for gene exchange.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 85 (1993), S. 994-1000 
    ISSN: 1432-2242
    Keywords: Brassica napus ; DNA fingerprinting ; Simple repetitive sequences ; Cultivar identification ; DNA methylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The Brassica napus genome has been investigated by DNA fingerprinting with six synthetic oligonucleotide probes complementary to simple repetitive sequences, namely (GATA)4, (GACA)4, (GGAT)4, (CA)8, (CT)8 and (GTG)5. While all sequence motifs were found to be present in the B. napus genome, their organization and abundance varied considerably. Among the investigated probes, (GATA)4 revealed the highest level of intraspecific polymorphism and distinguishes not only between cultivars but even between different individuals belonging to the same cultivar. In contrast, (GTG)5, (GACA)4 and (GGAT)4 produced relatively homogeneous fingerprint patterns throughout different cultivars, while hybridization to (CT)8 and (CA)8 resulted in only a few weak bands superimposed on a smear. The isoschizomeric pair Hpa II and Msp I revealed the presence of methylated cytosines in the vicinity of (GATA)m repeats. The applicability of simple repetitive sequence polymorphisms as molecular markers for Brassica species is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 63
    ISSN: 1432-2242
    Keywords: Brassica napus ; BrdU ; Embryogenesis ; Microspore and pollen culture ; DNA synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The dynamics of nuclear DNA synthesis were analysed in isolated microspores and pollen of Brassica napus that were induced to form embryos. DNA synthesis was visualized by the immunocytochemical labelling of incorporated Bromodeoxyuridine (BrdU), applied continuously or as a pulse during the first 24 h of culture under embryogenic (32 °C) and non-embryogenic (18 °C) conditions. Total DNA content of the nuclei was determined by microspectrophotometry. At the moment of isolation, microspore nuclei and nuclei of generative cells were at the G1, S or G2 phase. Vegetative nuclei of pollen were always in G1 at the onset of culture. When microspores were cultured at 18 °C, they followed the normal gametophytic development; when cultured at 32 °C, they divided symmetrically and became embryogenic or continued gametophytic development. Because the two nuclei of the symmetrically divided microspores were either both labelled with BrdU or not labelled at all, we concluded that microspores are inducible to form embryos from the G1 until the G2 phase. When bicellular pollen were cultured at 18 °C, they exhibited labelling exclusively in generative nuclei. This is comparable to the gametophytic development that occurs in vivo. Early bicellular pollen cultured at 32 °C, however, also exhibited replication in vegetative nuclei. The majority of vegetative nuclei re-entered the cell cycle after 12 h of culture. Replication in the vegetative cells preceded division of the vegetative cell, a prerequisite for pollen-derived embryogenesis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    Transgenic research 2 (1993), S. 208-218 
    ISSN: 1573-9368
    Keywords: Agrobacterium ; plant transformation ; helper plasmids ; host range ; Ti plasmid ; T-DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We describe the construction of new helper Ti plasmids forAgrobacterium-mediated plant transformation. These plasmids are derived from three differentAgrobacterium tumefaciens Ti plasmids, the octopine plasmid pTiB6, the nopaline plasmid pTiC58, and the L,L-succinamopine plasmid pTiBo542. The T-DNA regions of these plasmids were deleted using site-directed mutagenesis to yield replicons carrying thevir genes that will complement binary vectorsin trans. Data are included that demonstrate strain utility. The advantages ofAgrobacterium strains harbouring these ‘disamed’ Ti plasmids for plant transformation viaAgrobacterium are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Springer
    Transgenic research 2 (1993), S. 356-364 
    ISSN: 1573-9368
    Keywords: Brassica napus ; oilseed rape ; transgenic crops ; pollen dispersal ; insect pollination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The objective of this study was to evaluate pollen dispersal inBrassica napus (oilseed rape). The selectable marker, used to follow pollen movement, was a dominant transgene (bar) conferring resistance to the herbicide glufosinate-ammonium. Transgenic and non-transgenic plants of the cultivar Westar were planted in a 1.1 ha field trial, with the transgenic plants in a 9 m diameter circle at the centre, surrounded by non-transgenic plants to a distance of at least 47 m in all directions. A 1 m circle of non-transgenic plants was sown in the centre of the transgenic area to allow estimation of the level of pollen dispersal when plants were in close contact. Honeybee hives were placed at the trial site to optimize the opportunity for cross-pollination. During the flowering period, regular observations were made of the number of plants flowering and the number and type of insects present in 60 1 m2 areas. These areas were located uniformly around the plot at distances of 1, 3, 6, 12, 24, 36 and 47 m from the edge of the 9 m circle of transgenic plants. Seed samples were harvested from each of the 7 distances so that approximately 20% of the circumference of the plot was sampled at each distance. The centre non-transgenic circle was also sampled. Plants were grown from the seed samples and sprayed with glufosinate to estimate the frequency of pollen dispersal at each distance. In order to screen enough samples to detect low frequency cross-pollination events, seed samples were tested in the greenhouse and on a larger scale in the field. Results were confirmed by testing progeny for glufosinate resistance and by Southern blot analysis. The estimated percentage of pollen dispersal in the non-transgenic centre circle was 4.8%. The frequency was estimated to be 1.5% at a distance of 1 m and 0.4% at 3 m. The frequency decreased sharply to 0.02% at 12 m and was only 0.00033% at 47 m. No obvious directional effects were detected that could be ascribed to wind or insect activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 1615-6102
    Keywords: Acetosyringone ; Agrobacterium ; Carrot ; Cell cycle ; GUS assay ; Indole acetic acid levels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Localization of target cells forAgrobacterium-mediated transformation in the carrot root disc model has been achieved after inoculation with a disarmedA. tumefaciens strain harbouring a GUS-intron construct. The first GUS positive cells could be detected on both sides of the discs 48 h after inoculation. The transformed cells were always more numerous on the apical side, mainly localized in the intrafascicular cambium and in the immature phloem strands. The kinetics of free endogenous IAA levels on both sides after wounding have been determined, indicating that rapid IAA accumulation on the apical side was not simply due to polar migration from the basal side. Attempts to optimize transformation efficiency were made by pretreating the discs with various concentrations of acetosyringone (AS) and/or naphthalene acetic acid (NAA). Surprisingly, while 25 μM AS applied to bacteria prior to the inoculations was ineffective, the same AS concentration applied as a pretreatment to the discs strongly increased the number of transformed cells in the target tissues and decreased the lag time for the appearance of the first GUS positive cells. NAA pretreatment on the basal side enhanced the AS effect. AS pretreatment was found both to advance the reentry of competent cells with a potential for cell division into the S phase of the cell cycle and to stimulate bacterial attachment to the cell walls. The relationship between transformation efficiency and DNA synthesis in the host cells is discussed. AS treatment of plant tissues prior to inoculation is proposed as a means of increasing the transformation rates.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 67
    ISSN: 1615-6102
    Keywords: Brassica napus ; Cell division ; High temperature ; Microspore ; Embryogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Brassica napus cv. Topas microspores isolated and cultured near the first pollen mitosis and subjected to a heat treatment develop into haploid embryos at a frequency of about 20%. In order to obtain a greater understanding of the induction process and embryogenesis, transmission electron microscopy was used to study the development of pollen from the mid-uninucleate to the bicellular microspore stage. The effect of 24 h of high temperature (32.5 °C) on microspore development was examined by heat treating microspore cultures or entire plants. Mid-uninucleate microspores contained small vacuoles. Late-uninucleate vacuolate microspores contained a large vacuole. The large vacuole of the vacuolate stage was fragmented into numerous small vacuoles in the late-uninucleate stage. The late-uninucleate stage contained an increased number of ribosomes, a pollen coat covering the exine and a laterally positioned nucleus. Prior to the first pollen mitosis the nucleus of the lateuninucleate microspore appeared to be appressed to the plasma membrane; numerous perinuclear microtubules were observed. Microspores developing into pollen divided asymmetrically to form a large vegetative cell with amyloplasts and a small generative cell without plastids. The cells were separated by a lens-shaped cell wall which later diminished. At the late-bicellular stage the generative cell was observed within the vegetative cell. Starch and lipid reserves were present in the vegetative cell and the rough endoplasmic reticulum and Golgi were abundant. The microspore isolation procedure removed the pollen coat, but did not redistribute or alter the morphology of the organelles. Microspores cultured at 25 °C for 24 h resembled late-bicellular microspores except more starch and a thicker intine were present. A more equal division of microspores occurred during the 24 h heat treatment (32.5 °C) of the entire plant or of cultures. A planar wall separated the cells of the bicellular microspores. Both daughter cells contained plastids and the nuclei were of similar size. Cultured embryogenie microspores contained electron-dense deposits at the plasma membrane/cell wall interface, vesicle-like structures in the cell walls and organelle-free regions in the cytoplasm. The results are related to embryogenesis and a possible mechanism of induction is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 174 (1993), S. 147-157 
    ISSN: 1615-6102
    Keywords: Abscisic acid ; Brassica napus ; Embryo maturation ; Reserves metabolism ; Somatic embryos ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A comparison of embryos, cultured for increasing periods of time with and without abscisic acid (ABA), was undertaken to investigate, at the ultrastructural level, the influence of this growth regulator on the maturation of rapeseed (Brassica napus) somatic embryos. In the absence of ABA, the embryos germinated precociously while lipid bodies (LB), which were not numerous, soon degraded, as revealed by a depletion process associated with the appearance of morphologically mature glyoxysomes and an increase in the number of mitochondria. Moreover, a lack of protein bodies indicated that storage protein accumulation was not initiated under these conditions. On the contrary, the addition of ABA (10 μM) induced marked modification of embryo metabolism. Indeed, ABA completely prevented precocious embryo germination and inhibited lipid reserve catabolism. Moreover, the formation of small vacuoles and proliferation of rough endoplasmic reticulum in their vicinity suggested the onset of storage protein accumulation. After 15 days in the presence of ABA, the embryos contained abundant lipid and protein bodies. Nevertheless, these somatic embryos were not exactly the same as their mature zygotic counterparts since differences were found in chloroplasts, amyloplasts, and nuclear structures. These observations suggest that additional factors might be required to obtain fully mature somatic embryos.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 240 (1993), S. 49-57 
    ISSN: 1617-4623
    Keywords: Agrobacterium ; Microbial evolution ; RFLP analysis ; Ti plasmids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The octopine/cucumopine (o/c) Ti plasmids of the grapevine-associated Agrobacterium vitis strains constitute a family of related DNA molecules. Restriction maps were established of two limited-host-range o/c Ti plasmids, pTiAg57 and pTiAB3, and of the wide-host-range o/c Ti plasmid pTiHml. Together with the previously obtained map of the wide-host-range o/c Ti plasmid pTiTm4, about 1000 kb were mapped with a resolution of 0.2 kb, allowing a detailed comparison of the various structures. One region of the o/c Ti plasmids is highly conserved and differs mainly by the presence or absence of relatively small DNA fragments (0.9–2.7 kb); the other region has been modified more extensively and carries large sequences specific for each Ti plasmid type. The sequence similarity within large conserved regions shows that these plasmids have diverged recently and that their evolution was driven by large-scale genetic events rather than single nucleotide changes. These results have important implications for studies on bacterial evolution.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 70
    ISSN: 1617-4623
    Keywords: Intrachromosomal recombination ; Recombination frequency ; Allelic position ; Non-allelic position ; Brassica napus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have previously described a non-selective method for scoring somatic recombination in the genome of whole plants. The recombination substrate consists of a defective partial dimer of Cauliflower Mosaic Virus (CaMV) sequences, which can code for production of viable virus only upon homologous recombination; this leads to disease symptoms on leaves. Brassica napus plants (rapeseed) harbouring the recombination substrate as a transgene were used to examine the time in plant development at which recombination takes place. The analysis of three transgene loci revealed recombination frequencies specific for each locus. Recombination frequencies were increased if more than one transgene locus was present per genome, either in allelic (homozygosity of the transgene locus) or in non-allelic positions. In both cases, the overall recombination frequency was found to be elevated to approximately the sum of the frequencies for the individual transgene loci or slightly higher, suggesting that the respective transgene loci behave largely independently of each other. For all plants tested (single locus, two or multiple loci) maximal recombination frequencies were of the order of 10−6 events per cell division.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 71
    ISSN: 1617-4623
    Keywords: Agrobacterium ; Nopaline ; Gene regulation ; Protein-DNA interaction ; DNA topology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nocR gene of Agrobacterium tumefaciens Ti plasmid pTiT37 is the regulatory gene of the nopaline catabolism (noc) operon of pTiT37. We have cloned and sequenced nocR, which encodes a DNA-binding protein. The deduced amino acid sequence is similar to those of members of the LysR family of prokaryotic activator proteins. Gel retardation experiments demonstrated that the NocR protein binds to the nocR promoter in both the presence and absence of nopaline. The increased mobility of the complex and alterations in the DNase I footprints revealed a nopaline-induced conformational change in the NocR-DNA complex. Sequence analysis of the NocR binding site indicated the presence immediately downstream of the −10 sequence of the nocR promoter of a 12 by putative operator overlapping a consensus gyrase recognition sequence and an 18 by long alternating purine-pyrimidine sequence. These results suggest that nopaline-induced alterations in the NocR protein-nocR promoter complex might control gene expression in the noc operon.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 1573-5044
    Keywords: Agrobacterium ; Dendranthema grandiflora ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In an attempt to develop a system for producing transformed plants from explants ofDendranthema grandiflora, the susceptibility of the cultivar Super White to various wild-type strains ofAgrobacterium tumefaciens andA. rhizogenes was investigated. Tumour formation was not a reliable indicator of the ability of a related disarmed strain to mediate transformation. Following inoculation of explants with disarmedAgrobacterium strains, a number of shoots developed on selective media. However, none of these shoots were transformed. By co-cultivating stem internode explants with a mixed inoculum of wild-type and disarmed strains, it was possible to obtain a callus stably transformed withAgrobacterium carrying a disarmed T-DNA. Histological analysis of explants revealed that shoot regeneration initially occurred from the cells of the epidermis and subsequently from the cortex. However, the cells which were susceptible to T-DNA transfer were confined to the vascular tissue.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 1573-5060
    Keywords: Brassica napus ; microspore derived population ; RAPD ; RFLP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The segregation of RFLP and RAPD markers was compared in two oilseed rape (Brassica napus L.) breeding populations from the cross ‘Topas’ x R4, the latter being a low linolenic mutation line. A total progeny of 68 F2 and 40 microspore derived plants were studied with 25 markers. The results indicated a significant excess of ‘Topas’ alleles at five RAPD loci in the microspore derived population. This suggests that genomic regions which probably affect microspore culture ability do not have identical distribution in the two population types.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Euphytica 74 (1993), S. 165-185 
    ISSN: 1573-5060
    Keywords: transgenic legumes ; genetic engineering ; particle bombardment ; Agrobacterium ; direct DNA transfer ; crop legumes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The absence of variety-independent gene transfer methods for major agronomic species has, until now, limited the usefulness of recombinant DNA techniques to crop improvement programs. Until recently, only Solanaceous crops could be used to study fundamental and applied problems in plant sciences. During the past five years rapid advances in cell biology, in combination with the development of novel gene transfer methodology allowed utilization of the tools of plant molecular biology in conventional breeding programs. Cereal and leguminous species were considered to be recalcitrant to genetic manipulation. As a result of the development of direct DNA transfer methodology into organized tissue, we are now in a position to introduce any foreign gene into almost all of the major cereals and legumes. This can be achieved efficiently, often in a variety-independent fashion. The object of this review is to provide a comprehensive account of the state of the art in gene transfer for the cultivated leguminous crops. Important oilseed and feed species primarily in industrialized countries, as well as minor but equally important species for sustaining growth populations in developing countries will be examined. Advantages of the various gene transfer methods that were shown to be useful for specific crops, as well as limitations and problems associated with each crop and gene transfer method will be discussed. Data from field trials of transgenic legumes, where available, will be presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 153 (1993), S. 19-31 
    ISSN: 1573-5036
    Keywords: Brassica carinata ; Brassica napus ; calcium ; chloride ; growth analysis ; leaf area ratio ; magnesium ; net assimilation rate ; potassium ; relative growth rate ; seawater ; sodium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The response of two rapid-cycling Brassica species differing in tolerance to seawater salinity was studied over a period of 24 days. In response to 8 dS m−1 salinity, the two Brassica species showed clear differences in the changes in relative growth rate (RGR), net assimilation rate (NAR) and leaf area ratio (LAR). The RGR of B. napus was slightly reduced by salinity, wheareas the RGR of B. carinata was largely reduced in the early stages of salinization. LAR of B. napus was affected by salinity in the later stages of growth and significantly correlated with the reduction in RGR. On the other hand, the NAR of B. carinata was decreased by salinity, corresponding to the decrease of the RGR of B. carinata. The NAR of B. napus was not significantly affected by salinity according to analysis of covariance. The shoot concentrations of Na, Mg and Cl increased while the concentrations of K and Ca decreased sharply during the first 5 days of salinization; subsequently, all ion concentrations remained relatively constant. The concentrations of Na, K, Ca, Mg and Cl in the root were similarly affected by salinity. There were no significant differences of ion concentrations between species that could be related to the differences in salt tolerance. Thus, the differences in salt tolerance between species can not be related to differences in specific-ion effects, but may be related to some factor that reduces the NAR of B. carinata during the early stages of growth.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 76
    ISSN: 1573-5036
    Keywords: Brassica napus ; K release ; nonexchangeable potassium ; particle size ; rhizosphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The release of nonexchangeable potassium by the different particle size fractions of two soils was studied with a culture device designed to confine soil samples in the rhizosphere of rape (Brassica napus cv Drakkar). After 8 days of cropping, the contribution of nonexchangeable K to K uptake ranged from 50% in the fine clay to 80–100% in the coarser fractions. Due to their high supplying power and their relative abundance, the silt fractions provided a major part of the supply of K by these soils.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 77
    ISSN: 1573-5060
    Keywords: Brassica napus ; cross prediction ; genetic parameters ; oilseed rape ; SSD lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The reliability of a selection among crosses based on a cross prediction in early generations was investigated in spring rapeseed. The performance of the parents, the F2 generation, and random F3 lines from four crosses were used to predict the probability of finding superior recombinant lines. These predictions were made for two years and compared with the observed performance of F6 lines in the second of these two years and in an additional year. Predicted and observed performances coincided reasonably for the characters plant height, standability, maturity and an index calculated from seed yield, oil content and protein content. For seed yield and flowering time, the predictions were very unreliable. In conclusion, prediction methods may be useful in rapeseed breeding, if quality traits are of major commercial interest.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 78
    ISSN: 1573-5060
    Keywords: Brassica juncea ; Brassica napus ; Moricandia arvensis ; intergeneric hybridization ; ovary culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wide hybridizations between M. arvensis and Brassica amphidiploid species (B. napus and B. juncea) were carried out in order to incorporate desirable traits of M. arvensis into Brassica crops. Crossing barriers between them were present without the use of in vitro techniques. F1 hybrids have been produced through ovary culture, when M. arvensis were used as a female parent. Higher hybrid embryo productivity (3.07 embryos per pollination) was obtained in the cross of M. arvensis x B. napus than in that of M. arvensis x B. juncea (0.79 embryos). The hybridity was confirmed by morphology, cytology, isozyme and Southern analyses. The first backcrossing progenies and open pollinated ones were produced.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 79
    ISSN: 1573-5060
    Keywords: Albugo candida ; Brassica juncea ; Brassica napus ; EDTA ; gamma-ray ; interspecific cross ; leaf waxiness ; white rust inheritance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Three interspecific crosses made between Brassica juncea and Brassica napus revealed digenic control with epistatic interaction for white rust resistance trait. The investigation also indicated a close association of parental species type and different grades of leaf waxiness with white rust resistance. It is possible to recover waxy or medium waxy juncea types with white rust resistance, though in low frequency. Treatment of hybrid seeds with EDTA and low doses of gamma-rays seem to have little effect on shuffeling of genomes and genes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 1573-5060
    Keywords: Brassica napus ; doubled haploid ; inheritance ; seed colour ; vernalization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Doubled haploid (DH) and F2 populations were used to study the inheritance of seed colour and one DH population was used to study vernalization requirement in Brassica napus. Seed colour was primarily determined by the maternal genotype, but effects of the paternal parent were obvious in a reciprocal F2. The seed colour distributions in the populations fit a trigenic ratio with black seed colour being dominant over yellow seed colour. In the proposed model, which was supported by segregation ratios in an F2 population from a cross with a black-seeded maternal parent (but not its reciprocal) and segregation ratios in 4 DH populations, black seeds were formed when the A gene was homozygous dominant and at least one dominant allele was present at the B locus, brown seeds developed when one or more recessive alleles were present at the A locus and one (or more) dominant alleles was (were) present at any of the three loci and yellow seeds occurred when all three loci were homozygous recessive. The vernalization study showed that the spring habit was dominant to the winter habit and that the requirement for vernalization was controlled by a major and a minor gene. The enhanced resolution of genetic classes afforded by the use of DHs allowed the relative effects of the major and minor vernalization genes to be determined. In the proposed model the major gene was sufficient to allow nonvernalized plants to flower in 62 days or less, the minor gene allowed nonvernalized plants to flower in 63 to 77 days and double recessive genotypes required more than 77 days to flower without vernalization.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 1573-5060
    Keywords: Brassica napus ; ×Brassicoraphanus ; Heterodera schachtii ; intergeneric crosses ; introgression ; meiosis ; nematode resistance ; Raphanus sativus ; rape kale ; oil-seed rape ; fodder rape ; raparadish ; radish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The possibilities to transfer important traits and in particular resistance to the beet cyst nematode (Heterodera schachtii, abbrev. BCN) from Raphanus sativus to Brassica napus were investigated. For these studies B. napus, R. sativus, the bridging hybrid ×Brassicoraphanus (Raparadish) as well as offspring of the cross ×Brassicoraphanus (Raparadish) ×B. napus were used. Reciprocal crosses between B. napus and R. sativus were unsuccessful, also with the use of embryo rescue. Crosses between ×Brassicoraphanus as female parent and B. napus resulted in a large number of F1 hybrids, whereas the reciprocal cross yielded mainly matromorphic plants. BC1, BC2 and BC3 plants were obtained from backcrosses with B. napus, which was used as the male parent. F1 hybrids and BC plants showed a large variation for morphology and male and female fertility. Cuttings of some F1 and BC1 plants, obtained from crosses involving resistant plants of ×Brassicoraphanus, were found to possess a level of resistance similar to that of the resistant parent. These results and indications for meiotic pairing between chromosomes of genome R with those of the genomes A and/or C suggest that introgression of the BCN-resistance of Raphanus into B. napus may be achieved.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 82
    ISSN: 1432-203X
    Keywords: Genetic transformation ; Oilseed Brassica campestris ; Agrobacterium ; Shoot differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Protocols were developed for efficient shoot regeneration from hypocotyl and cotyledon explants of oilseed Brassica campestris (brown sarson) cv. ‘Pusa Kalyani’. These were used for genetic transformation by an Agrobacterium based binary vector carrying neomycin phosphotransferase (npt) gene and β-glucuronidase (gus)-intron gene for plant cell specific expression. Transformed plants were recovered from hypocotyl explants at a frequency of 7–13%. Addition of silver nitrate markedly enhanced shoot regeneration in hypocotyl explants under non-selection conditions and was found to be an absolute requirement under selection conditions. Cotyledon explants, inspite of being more regenerative, proved to be highly refractory to transformation. Only two chimeric transformed shoots were obtained from more than 10,000 cotyledons treated with Agrobacterium. In hypocotyl explants, shoot regeneration occurred from the vascular parenchyma both with and without the intervention of callus phase. Only the shoot buds differentiating from callus tissue were positive for GUS activity. In cotyledons, shoot buds originated only directly from the vascular parenchyma, generally at a distance of about 450–625 μ from the cut surface. Such shoots were negative for GUS activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 83
    ISSN: 1432-2048
    Keywords: Agrobacterium ; Auxin (tumor tissue) ; Compensation (tms genes) ; Nicotiana (cell transformation) ; tms genes ; Tumor morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have studied the mechanism of auxin autonomy in tobacco (Nicotiana tabacum L.) crowngall tissues transformed by the auxin-mutant (tms −) A66 strain of Agrobacterium tumefaciens. Normally, tms − tobacco tumor tissues require the formation of shoots to exhibit auxin-independent growth in culture. We have isolated from tms − tobacco cells several stable variants that are fully hormone-independent and grow rapidly as friable, unorganized tissues, thus mimicking the growth and morphology of tms + tobacco cells that produce high levels of auxin. However, none of the variants contained the high levels of auxin found in tms + tumor cells. The variants could be divided into two classes with respect to their response to applied auxin. The first class was highly sensitive to applied auxin: low concentrations (1 μM) of α-naphthaleneacetic acid (NAA) severely inhibited growth and markedly stimulated the accumulation of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC). The second class of variants showed a low sensitivity to applied auxin: growth was promoted by concentrations of NAA up to 10 μM, and growth inhibition and high ACC levels were observed only at high NAA concentrations (100 μM). Unorganized variants with low auxin sensitivity were also isolated from a variant line with high auxin sensitivity. The isolation of tumor cells that exhibited the growth phenotype of tms + cells while retaining the low auxin content and low auxin sensitivity of tms − cells indicates that full hormone autonomy, characteristic of wild-type crown-gall tumors, can be achieved by a mechanism that is independent of changes in the auxin physiology of the cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 84
    ISSN: 1432-2048
    Keywords: Agrobacterium ; Auxin (tumor tissue) ; Compensation (tms genes) ; Nicotiana (cell transformation) ; tms genes ; Tumor morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have studied the mechanism of auxin autonomy in tobacco (Nicotiana tabacum L.) crowngall tissues transformed by the auxin-mutant (tms −) A66 strain ofAgrobacterium tumefaciens. Normally,tms − tobacco tumor tissues require the formation of shoots to exhibit auxin-independent growth in culture. We have isolated fromtms − tobacco cells several stable variants that are fully hormone-independent and grow rapidly as friable, unorganized tissues, thus mimicking the growth and morphology oftms + tobacco cells that produce high levels of auxin. However, none of the variants contained the high levels of auxin found intms + tumor cells. The variants could be divided into two classes with respect to their response to applied auxin. The first class was highly sensitive to applied auxin: low concentrations (1 μM) of α-naphthaleneacetic acid (NAA) severely inhibited growth and markedly stimulated the accumulation of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC). The second class of variants showed a low sensitivity to applied auxin: growth was promoted by concentrations of NAA up to 10 μM, and growth inhibition and high ACC levels were observed only at high NAA concentrations (100 μM). Unorganized variants with low auxin sensitivity were also isolated from a variant line with high auxin sensitivity. The isolation of tumor cells that exhibited the growth phenotype oftms + cells while retaining the low auxin content and low auxin sensitivity oftms − cells indicates that full hormone autonomy, characteristic of wild-type crown-gall tumors, can be achieved by a mechanism that is independent of changes in the auxin physiology of the cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 85
    ISSN: 1432-2048
    Keywords: Agrobacterium ; Arabidopsis ; Cotyledon ; Root explant (in vitro culture) ; Transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The insertion of foreign DNA in plants occurs through a complex interaction between Agrobacteria and host plant cells. The marker gene β-glucuronidase of Escherichia coli and cytological methods were used to characterize competent cells for Agrobacterium-mediated transformation, to study early cellular events of transformation, and to identify the potential host-cell barriers that limit transformation in Arabidopsis thaliana L. Heynh. In cotyledon and leaf explants, competent cells were mesophyll cells that were dedifferentiating, a process induced by wounding and-or phytohormones. The cells were located either at the cut surface or within the explant after phytohormone pretreatment. In root explants, competent cells were present in dedifferentiating pericycle, and were produced only after phytohormone pretreatment. Irrespective of their origin, the competent cells were small, isodiametric with thin primary cell walls, small and multiple vacuoles, prominent nuclei and dense cytoplasm. In both cotyledon and root explants, histological enumeration and β-glucuronidase assays showed that the number of putatively competent cells was increased by preculture treatment, indicating that cell activation and cell division following wounding were insufficient for transformation without phytohormone treatment. Exposure of explants for 48 h to A. tumefaciens produced no characteristic stress response nor any gradual loss of viability nor cell death. However, in the competent cell, association between the polysaccharide of the host cell wall and that of the bacterial filament was frequently observed, indicating that transformation required polysaccharide-to-polysaccharide contact. Flow cytofluorometry and histological analysis showed that abundant transformation required not only cell activation (an early state exhibiting an increase in nuclear protein) but also cell proliferation (which in cotyledon tissue occurred at many ploidy levels). Noncompetent cells could be made competent with the appropriate phytohormone treatments before bacterial infection: this should aid analysis of critical steps in transformation procedures and should facilitate developing new strategies to transform recalcitrant plants.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 1432-2145
    Keywords: Self-incompatibility ; S-locus genes ; Brassica napus ; Transgenic plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Self-compatible Brassica napus var ‘Westar’ was transformed with SLG, the S-locus-derived gene that encodes S-locus-specific glycoproteins (SLSG). Four allelic variants of SLG isolated from self-incompatible B. oleracea and B. campestris strains homozygous for different S alleles were used. We show that the transgenic plants synthesized SLSG with the same apparent charge, molecular weight, and antigenic properties as that produced by the corresponding self-incompatible strains from which the cloned SLG genes were isolated. In addition, transgene-encoded SLSG was detected specifically in the papillar cells of the stigma, and was correctly targeted to the papillar cell wall. However, SLSG was produced at reduced levels in transgenic plants relative to self-incompatible strains. The introduction of the SLG genes did not confer a self-incompatibility phenotype on the ‘Westar’ cultivar.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 87
    ISSN: 1432-203X
    Keywords: Agrobacterium ; Plant Transformation ; Gene Expression ; CaMV 35S Promoter ; Physalis ixocarpa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A protocol for the Agrobacterium-mediated transformation of tomatillo was developed. Up to 40 transgenic plants could be obtained in experiments using 60 cotyledon expiants. The transformed nature of the regenerated plants was confirmed by NPT II and Southern blot hybridization analysis. Using the b-glucuronidase system the tissue specific and developmental patterns of expression of the Cauliflower Mosaic Virus 35S promoter were determined in transgenic tomatillo plants. It was found that this promoter is developmentally regulated during fruit and seed formation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 1432-203X
    Keywords: Arabidopsis thaliana ; Transformation ; Agrobacterium ; T-DNA ; Shoot regeneration ; Transgenic plant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The efficiency of Agrobacterium-mediated transformation of Arabidopsis thaliana was compared with different organs, Arabidopsis ecotypes, and Agrobacterium strains. Efficiency of shoot regeneration was examined using hypocotyl, cotyledon and root explants prepared from young seedlings. Hypocotyl expiants had the highest regeneration efficiency in all of the four Arabidopsis ecotypes tested, when based on a tissue culture system of callus-inducing medium (CIM: Valvekens et al. 1988) and shoot-inducing medium (SIM: Feldmann and Marks 1986). Histochemical analysis using the ß-glucuronidase (GUS) reporter gene showed that the gusA gene expression increased as the period of preincubation on CIM was extended, suggesting that dividing cells are susceptible to Agrobacterium infection. In order to obtain transgenic shoots, hypocotyl explants preincubated for 7 or 8 days on CIM were infected with Agrobacterium containing a binary vector which carries two drug-resistant genes as selection markers, and transferred to SIM for selection of transformed shoots. Of four Arabidopsis ecotypes and of three Agrobacterium strains examined, Wassilewskija ecotype and EHA101 strain showed the highest efficiency of regeneration of transformed shoots. By combining the most efficient factors of preincubation period, Arabidopsis ecotype, tissue, and bacterial strain, we obtained a transformation efficiency of about 80–90%. Southern analysis of 124 transgenic plants showed that 44% had one copy of inserted T-DNA while the others had more than one copy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 18 (1992), S. 875-884 
    ISSN: 1573-1561
    Keywords: Aggregation pheromone ; olfactometer ; field trapping ; Coleoptera ; Chrysomelidae ; Phyllotreta cruciferae ; Brassica napus ; crucifer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Laboratory olfactometer bioassays and field trapping experiments showed that the flea beetle,Phyllotreta cruciferae (Goeze), was highly attracted by oilseed rape(Brassica napus L.) when flea beetles were on the plant. This attraction was mediated by a flea beetle-produced aggregation pheromone based upon: (1) Oilseed rape damaged mechanically, or byP. cruciferae, or by diamondback moth,Plutella xylostella (L.), did not attractP. cruciferae. (2) Contact with the plants or feeding was required for the production of aggregation pheromone because oilseed rape alone was not attractive when separated from flea beetles by a screen. (3) Equal numbers of males and females were attracted.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 1573-5028
    Keywords: anther ; Arabidopsis thaliana ; Brassica napus ; tapetum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Brassica napus cDNA clone A9 and the corresponding Arabidopsis thaliana gene have been sequenced. The B. napus cDNA and the A. thaliana gene encode proteins that are 73% identical and are predicted to be 10.3 kDa and 11.6 kDa in size respectively. Fusions of an RNase gene and the reporter gene β-glucuronidase to the A. thaliana A9 promoter demonstrated that in tobacco the A9 promoter is active solely in tapetal cells. Promoter activity is first detectable in anthers prior to sporogenous cell meiosis and ceases during microspore premitotic interphase. The deduced A9 protein sequence has a pattern of cysteine residues that is present in a superfamily of seed plant proteins which contains seed storage proteins and several protease and α-amylase inhibitors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 19 (1992), S. 1049-1055 
    ISSN: 1573-5028
    Keywords: Brassica napus ; rapeseed ; gene expression ; nucleotide sequence ; storage proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have isolated a five-member gene subfamily which encodes cruciferin, a legumin-like 12S storage protein of Brassica napus L., and have analyzed the structure and expression of the family members in developing embryos. Sequence analysis has shown that the coding regions of all five genes are highly similar, with the two most divergent members of the family retaining 89% sequence identity. The analysis of this cruciferin gene family's expression indicates that the developmental pattern of expression of each gene is similar, and the steady-state mRNA levels of each gene are approximately equivalent to each other at all developmental stages.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 19 (1992), S. 1079-1083 
    ISSN: 1573-5028
    Keywords: oleosin ; embryogenesis ; cDNA ; Brassica napus ; oil-body protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Antibodies raised against purified rapeseed 19 kDa oleosin protein were used to screen an embryo-derived λgt11 expression library from Brassica napus. A near full-length cDNA clone, BnV, was isolated. The 781 bp cDNA contained an open reading frame of 549 bp followed by an untranslated region of 222 pb and a poly(A) region of 10 bp. Comparisons between this cDNA and a different oleosin cDNA previously isolated from the same library showed high degrees of sequence similarity in the central domain region and in the 3′ untranslated region. Sequence similarities between the derived protein sequence of this cDNA and all other known oleosin protein sequences are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 1573-5028
    Keywords: Brassica napus ; cruciferin ; seed globulin ; storage protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A gene encoding a subunit of the 12S storage globulin, cruciferin, in Brassica napus (oilseed rape) has been isolated and characterized. The gene consists of about 2200 bp including three short intervening sequences. Primer extension analysis showed that the major transcription start site is located 30 bp 5′ of the predicted ATG start codon. This gene belongs to one of three different major families encoding cruciferin subunits. By use of gene-family-specific probes and Southern blotting analysis the number of genes of the three different cruciferin subtypes in B. napus was estimated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 94
    ISSN: 1573-5028
    Keywords: acyl-(acyl carrier protein) thioesterase ; acyl carrier protein ; Brassica napus ; fatty acid synthesis ; rape ; seed development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The level of two thioesterases, acyl-CoA thioesterase and acyl-ACP thioesterase was determined during seed maturation in oil seed rape. Both thioesterase activities rose markedly prior to the onset of lipid accumulation, but the induction kinetics suggest that the activities reside on distinct polypeptides. Acyl-ACP thioesterase (EC 3.1.2.14) was purified 2000-fold using a combination of ion exchange, ACP-affinity chromatogr aphy, chromatofocusing and gel filtration. Using native gel electrophoresis, and assays for enzymic activity, two polypeptides were identified on SDS-PAGE as associated with the activity. Cleveland mapping of these polypeptides, of 38 kDa component and 33 kDa respectively, demonstrated that they are related. An antibody was prepared against the 38 kDa component, and this also recognises the 33 kDa polypeptide in highly purified preparations. Western blotting of a crude extract identifies one band at 38 kDa consistent with the 33 kDa component being a degradation product generated during purification. The native molecule has a Mr of 70 kDa indicating a dimeric structure. The enzyme has a pH optimum of 9.5 and shows strong preference for oleoyl-ACP as substrate. The intact enzyme has an N-terminus blocked to protein sequencing. We also found that two other polypeptides co-purify with acyl-ACP thioesterase under native conditions. The N-terminal amino-acid sequence of these polypeptides is shown and their possible identity is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 95
    ISSN: 1573-5028
    Keywords: β-D-glucuronidase ; mannopine synthase promoter ; Agrobacterium ; gene expression ; initiation of translation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transcriptional and translational fusions between the reading frame of the β-D-glucuronidase gene (gusA) and the 2′ as well as the 1′ promoter of mannopine synthase (mas), a TR locus of Agrobacterium tumefaciens, were made. The expression of these constructs was studied in the transgenic F1 offspring of independent tobacco transformants at the protein level by assaying for GUS activity and western blot analysis of the GUS protein and at the steady-state mRNA level. In leaves, stems and roots no correlation was found between steady-state levels of GUS mRNA and enzyme activity. In older tissues significantly higher GUS activities were found. This is explained by the stable character of the GUS protein together with an accumulation of protein upon ageing. Three to ten times higher GUS activities were found for in vitro grown plants than for greenhouse-grown plants of the same offspring, despite similar levels of GUS mRNA. Roots from in vitro grown plants display three to ten times higher GUS activities than stems and leaves. In transgenic plants grown in vitro, containing a translational fusion with two AUGs in phase, the initiation of translation in leaf material occurred at both AUGs. Initiation of translation at the first AUG, however, was ten times more frequent. In contrast, initiation in roots from in vitro grown plants occurred exclusively at the second AUG.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 96
    ISSN: 1573-5028
    Keywords: Agrobacterium ; rice ; transformation ; Ti plasmid ; GUS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transient expression of GUS in rice (Oryza sativa L.) mediated by Agrobacterium tumefaciens was characterized using binary vectors containing gusA genes that express minimal (pKIWI105 and pCNL1) or no (p35S-GUS-INT and pCNL56) GUS activity in bacteria. Four-day old seedlings obtained from seeds or immature embryos of rice were cut into shoot, root, and seed remnants and inoculated with various strains of A. tumefaciens. Transient GUS expression events were quantitated histochemically by determining the frequency of explants exhibiting blue spots indicative of GUS at four to six days after cocultivation with A. tumefaciens. A. tumefaciens strains that did not contain the gusA gene (At643) or a Ti-plasmid (At563 and At657) did not elicit any blue staining characteristic of GUS activity. Several parameters were important in obtaining efficient transient expression of GUS in rice mediated by A. tumefaciens. The growth regulator 2,4-D inhibited GUS expression if present during the seed germination period, but the presence of 6 mg/1 2,4-D during cocultivation of the explants with A. tumefaciens slightly enhanced GUS expression efficiency. All 21 rice cultivars tested expressed GUS after co-cultivation with A. tumefaciens. The GUS expression frequency was highest amongst the indica cultivars. The frequencies of GUS expression in japonica cultivars and in Oryza glaberrima cultivars (grown primarily in Africa) were generally one-half to one-third the level found for indica varieties. Leaf explants were more susceptible to A. tumefaciens-facilitated GUS expression than were roots or seed remnants. The vir genes of an agropine-type Ti-plasmid of A. tumefaciens were most effective in directing transient GUS expression in rice, whereas those of a nopaline-type and an octopine-type plasmid were less effective. We have also found that the frequency of transient expression of GUS was higher with pBIN19 as the precursor cloning vector than with pEND4K as the precursor cloning vector. Reasons for differences in effectiveness of these binary vectors are discussed. Using the conditions described here, A. tumefaciens-mediated frequencies of transient GUS expression in four-day old shoots of several rice cultivars were routinely in excess of 50%.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 97
    ISSN: 1573-5028
    Keywords: Agrobacterium ; binary vector ; CaMV 35S ; gene expression ; β-glucuronidase ; Nicotiana plumbaginifolia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A versatile gene expression cartridge and binary vector system was constructed for use in Agrobacterium-mediated plant transformation. The expression cartridge of the primary cloning vector, pART7, comprises of cauliflower mosaic virus Cabb B-JI isolate 35S promoter, a multiple cloning site and the transcriptional termination region of the octopine synthase gene. The entire cartridge can be removed from pART7 as a Not I fragment and introduced directly into the binary vector, pART27, recombinants being selected by blue/white screening for β-galactosidase. pART27 carries the RK2 minimal replicon for maintenance in Agrobacterium, the ColE1 origin of replication for high-copy maintenance in Escherichia coli and the Tn7 spectinomycin/streptomycin resistance gene as a bacterial selectable marker. The organisational structure of the T-DNA of pART27 has been constructed taking into account the right to left border, 5′ to 3′ model of T-DNA transfer. The T-DNA carries the chimaeric kanamycin resistance gene (nopaline synthase promoter-neomycin phosphotransferase-nopaline synthase terminator) distal to the right border relative to the lacZ′ region. Utilisation of these vectors in Agrobacterium-mediated transformation of tobacco demonstrated efficient T-DNA transfer to the plant genome.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 98
    ISSN: 1573-5028
    Keywords: methionine enhancement ; seed proteins ; Brassica napus ; transgenic expression ; Brazil nut ; nutritional quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have increased the methionine content of the seed proteins of a commercial winter variety of canola by expressing a chimeric gene encoding a methionine-rich seed protein from Brazil nut in the seeds of transgenic plants. Transgenic canola seeds accumulate the heterologous methionine-rich protein at levels which range from 1.7% to 4.0% of the total seed protein and contain up to 33% more methionine. The precursor of the methionine-rich protein is processed correctly in the seeds, resulting in the appearance of the mature protein in the 2S protein fraction. The 2S methionine-rich protein accumulates in the transgenic seeds at the same time in development as the canola 11S seed proteins and disappears rapidly upon germination of the seed. The increase in methionine in the canola seed proteins should increase the value of canola meal which is used in animal feed formulations.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 1573-5028
    Keywords: acyl carrier protein ; Brassica napus ; lipid synthesis ; seed-specific expression ; transgenic tobacco ; 5′ flanking region
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acyl carrier protein (ACP) is a key component of the fatty acid biosynthetic machinery in plants. A 1.4 kb 5′ flanking region of a Brassica napus ACP gene (ACP05) was transcriptionally fused to the reporter gene β-glucuronidase (GUS), and expression of the chimaeric gene monitored in transgenic tobacco. GUS activity was found to increase through seed development reaching a maximum value, coincident with the most active phase of storage lipid synthesis that was, on average, 100-fold higher than that observed in leaf. In control plants transformed with CaMV 35S-GUS constructs, GUS activity was similar in leaf and all stages of seed development. Based on average values, the level of GUS expression obtained via the ACP promoter was comparable to that obtained from the CaMV 35S promoter. We therefore conclude that the isolated 5′ ACP flanking sequence represents a strong promoter element involved in the developmental regulation of storage lipid synthesis in B. napus seed tissue. Putative regulatory elements in the 5′ upstream region of ACP05 were identified by dot matrix analysis and by sequence comparison with the upstream regions from a second seed-expressed rape ACP gene and from an Arabidopsis ACP gene.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 1573-5028
    Keywords: Brassica napus ; embryogenesis ; leucine-zipper motif ; oleosin ; oil-body protein ; seed development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sequence of an oleosin gene from Brassica napus has been determined. This gene contains a single intron of 437 bp and encodes a polypeptide of 195 amino acids. The oleosin gene product has an estimated molecular mass of 21.5 kDa and consists of a highly hydrophobic central domain flanked by relatively polar N- and C-terminal domains. The central domain is highly conserved between all oleosins sequenced to date and contains a run of periodically spaced leucine residues similar to that of a leucine-zipper motif. The gene has been shown to be expressed specifically in the embryo, maximally between 9 and 11 weeks after flowering, i.e. during the seed desiccation stage. Two transcriptional start sites have been mapped to -70 and -21 of the ATG and a putative ABA-responsive element and three repeated motifs have been identified in the promoter. These short promoter sequences could correspond to regulatory elements responsible for embryo-specific gene expression. Up to six genes exist in the oleosin gene family.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...