ibclogo XVI International Botanical Congess


Abstract Number: 3839
Session = 8.12.3


SHORT-DISTANCE TRANSPORT OF SPERM CELLS DURING FERTILIZATION IN ANGIOSPERMS


S.D. Russell, Dept of Botany & Microbiol., Univ. of Oklahoma, Norman, USA


During passage in the pollen tube, non-motile sperm cells are conveyed within a surrounding pollen plasma membrane, principally through actin-myosin interactions. Using immunogold electron microscopy, anti-myosin antibody labels the cytoplasmic face of the surrounding pollen plasma membrane, but does not appear to occur on the sperm cell surface. Newly-formed, isolated tobacco sperm cells infrequently undergo spontaneous fusion, although they later lose this ability, fusion may still be induced by enzymes, calcium or PEG. The sperm cell associated with the vegetative nucleus is consistently larger in tobacco, but smaller in Plumbago. Late in pollen tube growth, tobacco sperm cells diverge in size becoming clearly dimorphic upon arrival in the embryo sac, suggesting the potential for preferentiality during later fusion.


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