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  • Pollen  (10)
  • Nicotiana tabacum  (5)
  • Sperm cells  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Distribution of microtubules during the growth of tobacco pollen tubes
    Amsterdam : Elsevier
    Biology of the Cell 79 (1993), S. 125-132 
    Details
    ISSN: 0248-4900
    Keywords: Nicotiana tabacum ; acetylated α-tubulin ; confocal laser scanning microscope ; microtubules ; pollen tube growth ; tyrosinated α-tubulin
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0248-4900(93)90248-D
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  • 2
    Electronic Resource
    Electronic Resource
    Viral particles in developing pollen grains of Olea europaea (1977)
    Springer
    Planta 137 (1977), S. 1-4 
    Details
    ISSN: 1432-2048
    Keywords: Olea ; Pollen ; Viral particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Double-walled tubules containing rows of isodiametric virus particles were observed in developing pollen grains of Olea europaea L. cultivar Correggiolo. Sometimes the tubules are contained in another double-walled tubular structure or in a tubular endoplasmic reticulum cistern. The viruses are present in the cytoplasm from the microspore mother cell stage up to the microspore stage but just before the first haploid mitosis they are to be found only in the pores, inside the evaginations formed by the plasmalemma. During the last phase of pollen grain development, after the germinative pores are completed, the viruses disappear.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394426
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  • 3
    Electronic Resource
    Electronic Resource
    Germination and early tube development in vitro of Lycopersicum peruvianum pollen: Ultrastructural features (1977)
    Springer
    Planta 136 (1977), S. 239-247 
    Details
    ISSN: 1432-2048
    Keywords: Early tube development ; In vitro germination ; Lycopersicum ; Pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Morphologic changes occurring during pollen grain activation and ultrastructural features of Lycopersicum peruvianum Mill. pollen tube during the first stages of growth in vitro have been studied. The more evident morphologic changes during activation, in comparison to those already described for mature inactive pollen, concern dictyosomes, rough endoplasmic reticulum (RER), and ribosomes. The dictyosomes are very abundant and produce “large” and “small” vesicles. Near the germinative pores both types of vesicles are present, while all along the remaining cell wall only the large type is observed. These latter react weakly to Thiéry's test and probably contain a callose precursor necessary for the deposition of a callosic layer lining at first only the inner side of the functioning pore and occasionally the other two pores, and subsequently the entire inner surface of the cell wall. The small vesicles, highly positive to Thiéry's test, are present only near the pores and could be involved in the formation of the pectocellulosic layer of the tube wall. The setting free of RER cisterns, which in the mature inactive pollen were aggregated in stacks, coinciding with polysome formation and resumption of protein synthesis, is in accord with the hypothesized role of RER cistern stacks as a reserve of synthesizing machinery. The pollen tube reaches a definitive spatial arrangement soon after the generative cell and vegetative nucleus have moved into it. At this stage four different zones that reflect a functional specialization are present. In the apical and subapical zone two types of dictysosome-originated vesicles, similar to those found in the activated pollen grain, are present. Their role in the formation of the callosic and pectocellulosic wall layers seems to be the same as in the activated pollen grain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385991
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  • 4
    Electronic Resource
    Electronic Resource
    In vitro double fertilization in Nicotiana tabacum (L.): polygamy compared with selected single pair somatic protoplast and chloroplast fusions (2000)
    Springer
    Sexual plant reproduction 13 (2000), S. 113-117 
    Details
    ISSN: 1432-2145
    Keywords: Key words Cell fusion ; Gamete interaction ; In vitro polygamy ; Nicotiana tabacum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In vitro polygamy was studied mainly by using isolated sperm and central cells of tobacco in order to elucidate the mechanism that might be involved in preventing in vivo polygamy. In 17.5% 4000 M.W. polyethylene glycol, only when two sperm cells were made close enough to each other and adhered to a female cell simultaneously was polygamy possible. If one sperm cell fused with the egg or central cell, within 30 min another sperm cell could not fuse with the same egg or central cell. Similar phenomena were found in selected single somatic cell fusion. When more than two protoplasts adhered to each other simultaneously, fusion was always successful; after two protoplasts fused, within 30 min the fusion products could not fuse with another protoplast under the same conditions. This comparative study revealed this characteristic to be shared by both sexual and somatic cell fusion. However, after cytoplasm reorganization was complete in the fusion product, it was possible for the fusion product to fuse with the third protoplast. This indicates that the obstruction to additional fusion was present only during a certain period after the preceding fusion under certain condition. The possible reason for the effect is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970000044
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  • 5
    Electronic Resource
    Electronic Resource
    Effects of high humidity and temperature stress on pollen membrane integrity and pollen vigour in Nicotiana tabacum (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 137-141 
    Details
    ISSN: 1432-2145
    Keywords: Humidity ; Temperature stress ; Nicotiana tabacum ; Pollen germination ; Pollen membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The prolonged exposure of pollen Nicotiana tabacum to high humidity at both room temperature and 38° C did not affect membrane integrity as revealed by the fluorochromatic reaction (FCR) test, but did affect pollen vigour. At room temperature germination was not affected, although tube growth was reduced; at 38° C, there was both a reduction in tube growth and delayed germination. When the pollen was subjected to 1 h hydration followed by 1 h desiccation (up to a maximum of four cycles) at room temperature, a reduction in the FCR, germination and tube length after each desiccation treatment was observed. Subsequent hydration fully restored the FCR, but only partially restored germination and tube growth. At 38° C, however, FCR, germination, and tube growth were drastically reduced. The implications of these results on the relationship between FCR and germinability, the responses of pollen exposed to humidity and temperature stress in the field, and on pollen storage are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00192759
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  • 6
    Electronic Resource
    Electronic Resource
    Responses of tobacco pollen to high humidity and heat stress: viability and germinability in vitro and in vivo (1991)
    Springer
    Sexual plant reproduction 4 (1991), S. 104-109 
    Details
    ISSN: 1432-2145
    Keywords: High humidity and temperature stress ; Nicotiana tabacum ; Tobacco ; Pollen viability ; Vigour ; Semi-vivo technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Responses of pollen grains of Nicotiana tabacum to high humidity (95% RH, 4 h) and temperature (38°/45° C, 4 h) stresses were investigated. Pollen grains were subjected to only RH or only temperature, or to both of these stresses. Their viability was assessed on the basis of the fluorochromatic reaction (FCR) test, and vigour was assessed on the basis of the time taken for in vitro germination as well as on the emergence of pollen tubes through the cut end of semi-vivo implanted styles. None of the stress conditions affected pollen viability and high RH or high temperature stress did not individually affect pollen vigour. However, pollen vigour was markedly affected when both the stresses were given together. Pollen grains subjected to high RH at 38° C took a longer time to germinate in vitro and the pollen tubes emerged later from the cut end of the semi-vivo styles; division of the generative cell was also delayed. Pollen grains subjected to high RH at 45° C failed to germinate in vitro, but did germinate on the stigma. Many pollen tubes subjected to this treatment showed abnormalities, and the growth of pollen tubes in the pistil was much slower than that observed in other treatments. Pollen samples subjected to all of the stress conditions were able to induce fruit and seed set. The implications of these results on the relationship between the FCR test and viability, and between viability and vigour, especially in stressed pollen, are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00196495
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  • 7
    Electronic Resource
    Electronic Resource
    Brassica napus pollen development during generative cell and sperm cell formation (1991)
    Springer
    Sexual plant reproduction 4 (1991), S. 176-181 
    Details
    ISSN: 1432-2145
    Keywords: Pollen ; Brassica napus ; Mitoses ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Brassica napus pollen development during the formation of the generative cell and sperm cells is analysed with light and electron microscopy. The generative cell is formed as a small lenticular cell attached to the intine, as a result of the unequal first mitosis. After detaching itself from the intine, the generative cell becomes spherical, and its wall morphology changes. Simultaneously, the vegetative nucleus enlarges, becomes euchromatic and forms a large nucleolus. In addition, the cytoplasm of the vegetative cell develops a complex ultrastructure that is characterized by an extensive RER organized in stacks, numerous dictyosomes and Golgi vesicles and a large quantity of lipid bodies. Microbodies, which are present at the mature stage, are not yet formed. The generative cell undergoes an equal division which results in two spindle-shaped sperm cells. This cell division occurs through the concerted action of cell constriction and cell plate formation. The two sperm cells remain enveloped within one continuous vegetative plasma membrane. One sperm cell becomes anchored onto the vegetative nucleus by a long extension enclosed within a deep invagination of the vegetative nucleus. Plastid inheritance appears to be strictly maternal since the sperm cells do not contain plastids; plastids are excluded from the generative cell even in the first mitosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190001
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  • 8
    Electronic Resource
    Electronic Resource
    Isolation of male and female gametes in higher plants (1991)
    Springer
    Sexual plant reproduction 4 (1991), S. 145-154 
    Details
    ISSN: 1432-2145
    Keywords: Angiosperm gametes ; Egg cell ; Embryosac ; Gamete isolation ; Gametophytic cells ; Sperm cells ; Generative cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The availability of generative cells, sperm cells, embryo sacs and egg cells from angiosperm plants in isolated conditions has opened up many prospects: study of the mechanism of recognition and fusion between gametes of opposite sex and detailed observation of the process of fertilization, biochemical and genetic analysis of gamete-specific components and genetic engineering in combination with in vitro fertilization. This review provides a list of about ninety publications, in which the isolation of male or female angiosperm gametes and the closely related generative cells and embryo sacs is reported. The species used are summarized in two tables. A description is given of the diverse isolation techniques, which consist of enzymatic digestion, bursting of pollen by osmotic shock, squashing, grinding and micro-dissection. Viability of isolated cells and yield, two important aspects of biotechnological manipulation, are emphasized. A critical evaluation of the most significant results obtained so far with isolated material is presented together with notes on prospects for the future.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00189998
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  • 9
    Electronic Resource
    Electronic Resource
    Striped projections of the outer membrane of the generative cell in Convallaria majalis pollen (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 223-227 
    Details
    ISSN: 1432-2145
    Keywords: Pollen ; Generative cell ; Cytoskeleton ; Motility ; Myosin immunogold labelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In pollen grains of Convallaria majalis the outer membrane of the generative cell (GC) is the inner membrane of the vegetative cell (VC). Striped projections (SP) at the cytoplasmic face of the outer membrane of the GC were revealed by chemical fixation and also by a rapid freeze-fixation and freeze-substitution. The projections, located in groups on the protruding lobes of the GC, were arranged parallel to each other and were equally spaced (40 nm apart). The length of the SP, estimated from grazing sections of GC, was 400 nm. Each projection was composed of T-shaped elements, about 35 nm high, spaced at an average distance of 25 nm. SP were observed in mature, hydrated, activated and germinated pollen grains and seemed to be associated with microtubules and microfilaments of the VC. No evidence exists yet of SP on the sperm cell membrane. Immunogold labelling with anti-myosin antibodies showed many gold particles attached preferentially to the surface of the protruding lobes of the GC in the area of the projections. These results may suggest that the SP of Convallaria GC contain myosin-like protein and play an important role in the motility of the GC during pollen tube growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228941
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  • 10
    Electronic Resource
    Electronic Resource
    Microtubule organization in the sperm ofTradescantia virginiana (1988)
    Springer
    Protoplasma 146 (1988), S. 28-34 
    Details
    ISSN: 1615-6102
    Keywords: Generative cell ; Microtubule ; Sperm ; Pollen ; Tradescantia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Microtubules were visualized in the sperm ofTradescantia virginiana pollen tubes grownin vitro and processed for antitubulin immunocytochemistry. The sperm contain thick microtubule bundles from which emerge numerous branches of various dimensions disposed longitudinally and helically along the cell axis. Sperm are usually spindle or cigar-shaped, but cells of various sizes and shapes can be found. All contain microtubule arrays. No F-actin was detected in sperm using rhodamine-phalloidin staining. Sperm microtubules are discussed in terms of their potential roles in cell shaping and motility and their origin during generative cell division.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01354292
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