[The change of microtubule organization influencing cell ability for fusion]

It is well known that plants have ability to avoid polygamy in angiosperm, however, its mechanism is still poorly understood. In our previous work of in vitro fertilization we found that once an egg cell fused with a sperm cell, it could hardly fuse with other sperm within a certain period. Therefore we proposed that fusing egg cell must suffer some intrinsic changes during the fusion, such as the change of microtubule organization, which may prevent the egg cell from another fusion with extra sperm cells. In present work, the dynamic change of microtubule organization during the process of cell fusion in Nicotiana tabacum was observed through the single cell immunofluorescence microscopy. It was found that once cells began to adhere and fuse in Polyethylene Glycol (PEG), the microtubule immediately depolymerized. During this period of fusion and before microtubule polymerized again in the fusion product, the cell was unable to fuse with other cells. The results suggested microtubule organization was likely involved in the mechanisms of controlling cell fusion, and offered a clear indication that similar mechanism might also contribute to plant avoiding polygamy.