Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Nicotiana sylvestris  (4)
  • Pollen tube  (2)
  • Zea mays  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Lipid metabolism during germination of tobacco pollen
    Amsterdam : Elsevier
    Phytochemistry 27 (1988), S. 2027-2031 
    Details
    ISSN: 0031-9422
    Keywords: Nicotiana sylvestris ; Solanaceae ; acetate incorporation ; lipid composition ; phosphate incorporation. ; pollen germination
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0031-9422(88)80090-6
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Plasmatubules in the pollen tubes of Nicotiana sylvestris (1988)
    Springer
    Planta 173 (1988), S. 35-41 
    Details
    ISSN: 1432-2048
    Keywords: Membrane extension ; Nicotiana (plasmatubules) ; Nutrient uptake (pollen tube) ; Plasma membrane ; Plasmatubule ; Pollen tube
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrastructural studies of the pollen tubes of Nicotiana sylvestris grown in the pistil revealed an extensive development of plasmatubules formed by evaginations of the plasma membrane. The plasmatubules occurred as twisted tubular structures in the periplasmic space along the tube wall and, in cross section, exhibited circular profiles with an outer diameter of 28±4 nm. They were also seen in deep, pocket-like invaginations of the plasma membrane and in this case the profiles had an outer diameter of 34±8 nm. In the pocket-like invaginations they were partially branched and often closely packed to form groups with obvious patterns. The enlargement of the plasma-membrane area resulting from plasmatubules formed along the tube wall was about six-to tenfold. Pollen tubes grown in vitro exhibited poorly developed plasmatubules. It is suggested that the large extension of the plasma membrane could enhance the uptake of nutrients, and thus might be responsible for the comparatively fast growth of pollen tubes in the pistil. Moreover, it is also assumed that the turnover rate of the Golgi apparatus must be higher in pollen tubes growing in vivo than in vitro, in order to provide a sufficient amount of membrane for the formation of the plasma membrane with its tubular modifications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394484
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Membrane flow in plants: Fractionation of growing pollen tubes of tobacco by preparative free-flow electrophoresis and kinetics of labeling of endoplasmic reticulum and golgi apparatus with [3H]leucine (1986)
    Springer
    Protoplasma 132 (1986), S. 38-50 
    Details
    ISSN: 1615-6102
    Keywords: Pollen tube ; Endoplasmic reticulum ; Golgi apparatus ; Membrane biogenesis ; Plasma membrane (Tobacco)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tobacco (Nicotiana tabacum L.) pollen, germinated 4 hours in suspension culture, was labeled with radioactive leucine and fractionated into constituent membranes by the technique of preparative free-flow electrophoresis. Tubes were ruptured by sonication directly into the electrophoresis buffer. Unfortunately, the Golgi apparatus of the rapidly elongating pollen tubes did not survive the sonication step. However, it was possible to obtain useful fractions of endoplasmic reticulum and mitochondria. To obtain Golgi apparatus, glutaraldehyde was added to the homogenization buffer during sonication. Plasma membrane, which accounted for only about 3% of the total membrane of the homogenates as determined by staining with phosphotungstate at low pH, was obtained in insufficient quantity and fraction purity to permit analysis. Results show rapid incorporation of [3H]leucine into endoplasmic reticulum followed by rapid chase out. The half-time for loss of radioactivity from the pollen tube endoplasmic reticulum was about 10 minutes. Concomitant with the loss of radioactivity from endoplasmic reticulum, the Golgi apparatus fraction was labeled reaching a maximum 20 minutes post chase. The findings suggest flow of membranes from endoplasmic reticulum to the Golgi apparatus during pollen tube growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01275788
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Microtubules are involved in maintaining the cellular polarity in pollen tubes ofNicotiana sylvestris (1994)
    Springer
    Protoplasma 179 (1994), S. 5-15 
    Details
    ISSN: 1615-6102
    Keywords: Cellular polarity ; Colchicine ; Propham ; Microtubules ; Nicotiana sylvestris ; Nuclear positioning ; Pollen tubes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The polarity of a growing pollen tube is clearly reflected by a distinct zonation of the cytoplasmic content. The vegetative nucleus and the generative cell (GC) are located in the tip region of the tube, and the basal cytoplasmic portion is highly vacuolated. Using pollen tubes ofNicotiana sylvestris Spegazz. & Comes grown in vitro, we examined the effects of varying concentrations of the microtubule inhibitors colchicine and propham. The depolymerization of the cortical microtubules by 25 μM colchicine led to a disorganization of the cytoplasm, i.e., vacuolization of the tip region, and to a deranged position of both the vegetative nucleus and the generative cell. The same concentration of colchicine inhibited tube growth by 10–20% of the control. Mitosis of the GC was not affected. Only from concentrations of 200 μM the configuration of the GC's microtubules was altered and an inhibition of mitosis was observed. At this concentration the disorganization of the cytoplasm was always reversible, but neither inhibition of mitosis nor derangement of the nuclear positioning was. At 1,800 μM colchicine, pollen tube growth was inhibited by 50% of the control. Using propham, the same three steps of action were observed, although propham proved to be about a hundred times more effective than colchicine. We conclude that the cortical microtubules of the pollen tube are involved in maintaining cellular polarity, probably as a part of a heterogeneous cytoskeletal network including also microfilaments and membranous elements. Nuclear positioning seems to be dependent on both, the tube's cortical and the GC's microtubules. A possible involvement of the extracellular matrix in maintaining intracytoplasmic polarity is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01360732
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Ultrastructural responses of tobacco pollen tubes to heat shock (1989)
    Springer
    Protoplasma 153 (1989), S. 104-110 
    Details
    ISSN: 1615-6102
    Keywords: Nicotiana sylvestris ; Pollen tube growth ; Heat shock ; Ultrastructure ; Endoplasmic reticulum ; Mitochondria ; Golgi apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of elevated temperatures on semivivo growth and ultrastructure of tobacco pollen tubes was investigated. Tube growth was decreased by about 50% at 35 °C, independent of the duration of treatment, and at 40 °C and above there was no growth of tubes. Heat treatment caused ultrastructural changes like accumulation of membranous materials, concentric stacking of rough endoplasmic reticulum, reduction in vesicle production by dictyosomes, increase in the fenestrated regions of the Golgi cisternae, swelling of mitochondrial saccules and increase in the electron density of the mitochondrial matrix. Furthermore, the dictyosomes of the treated tubes showed significant increase in the number of cisternae from 30 to 45 °C. The temperature induced changes were persistant at least for 24 h in 35 °C grown pollen tubes. The possible reasons for the tube growth inhibition are discussed on the basis of the ultrastructural alterations caused by elevated temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01322470
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The anti-microtubule drug carbetamide stopsNicotiana sylvestris pollen tube growth in the style (1995)
    Springer
    Protoplasma 187 (1995), S. 182-191 
    Details
    ISSN: 1615-6102
    Keywords: Carbetamide ; Microtubules ; Pollen tubes ; Style growth ; Nicotiana sylvestris ; Herbicide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Recently, we found that the anti-microtubule drugs colchicine and propham caused the absence of microtubules and thus loss of cytoplasmic zonation in in vitro growing pollen tubes ofNicotiana sylvestris, but did not seriously affect growth. In the present study we used the herbicide carbetamide as an anti-microtubule drug. It had the same effect as colchicine and propham: the cytoplasm, including the generative cell, was no longer concentrated in the tip but was distributed randomly. In addition, ultrastructural investigations have shown that even the vesicle zone, usually found at the very tip of pollen tubes, had disappeared in some tubes. Nonetheless, in vitro growth was not inhibited by more than 20% over a period of 22 h. In contrast, tube growth in plants ceased 1 cm down in the style when carbetamide was applied to the stigma before pollination. At the lowest concentration causing this effect, microtubules of the vegetative cell had disappeared and the cytoplasm was distributed randomly, as it was for in vitro grown tubes. It can be concluded that microtubules of the vegetative cell are essential for pollen tube growth in the style.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280247
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The influence of chlorsulfuron and metsulfuron methyl on root growth and on the ultrastructure of root tips of germinating maize seeds (1996)
    Springer
    Plant and soil 180 (1996), S. 19-28 
    Details
    ISSN: 1573-5036
    Keywords: herbicides ; chlorsulfuron ; metsulfuron methyl ; root tip ultrastructure ; root growth ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seeds of Zea mays L., germinating in soil, were exposed to very low doses of the sulfonylurea herbicides chlorsulfuron and metsulfuron methyl. At a concentration of 0.012 mg L−1, chlorsulfuron caused 72% and metsulfuron methyl 55% growth reduction of the young primary roots. Both herbicides also caused obvious injuries to the root tips. Scanning electron microscopic observations of the root tip surfaces indicated an inhibition of slime secretion at a herbicide concentration of 1.5 mg L−1. Transmission electron microscopy revealed obvious changes to the nuclei and deformation of radial cell walls in the primary root cortex at 0.012 and 1.5 mg L−1 for both herbicides. Moreover, the secretory cells of the root cap periphery showed partially irregular deposition of premature cell wall or slime material at a concentration of 0.012 mg L−1 of both herbicides. From the results of our electron microscopic observations we conclude that the primary roots of maize seedlings are seriously affected by extremely low concentrations of even those herbicides which (as chlorsulfuron and metsulfuron methyl) have been developed to inhibit the growth of dicotyledonous weeds. Moreover, we suggest that the frequently observed growth retardation of crop seedlings is a consequence of early root tip injuries caused by herbicide residues in the soil. ei]H Lambers
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00015407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructural responses of root caps to the herbicides chlorsulfuron and metsulfuron methyl (1994)
    Springer
    Plant and soil 167 (1994), S. 127-134 
    Details
    ISSN: 1573-5036
    Keywords: herbicides ; chlorsulfuron ; metsulfuron methyl ; root cap ultrastructure ; root growth ; Pisum sativum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Herbicide residues may affect seedlings during early stages of their development. We studied this possibility by the use of light and electron microscopy after incubation of germinating seeds ofPisum sativum L. andZea mays L. with different concentrations of chlorsulfuron and metsulfuron-methyl. By in vitro experiments, we have shown that both herbicides caused growth reduction of the very young roots, and severe ultrastructural alterations and injuries of the root caps of both species. Chlorsulfuron caused increase of electron-dense material in the vacuoles, cytoplasmic degeneration even in the inner secretory cell layers of the cap, and disruption of the amyloplast envelopes with release of the statolithic starch grains. In the initial cell complex of the root cap, the herbicides caused the formation of large concentric aggregates of the rough ER and wall disformations in the cells adjacent to this complex. Scanning electron microscopic observations revealed a decrease of the slime layer ensheathing the root cap and the subapical root surface. We conclude that even in early stages of seed germination, both herbicides seriously affect the gravity perception centre (consisting of the statocytes), and the secretory tissue of the root caps, thus probably disturbing the processes of gravitropism and the protective slime secretion of the roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01587607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...