拟南芥授粉前后花粉与乳突细胞的超微结构

Ultrastructures of Pollen and Papillar Cell of Arabidopsis during Pollination

利用透射电子显微镜技术,对自交亲和植物拟南芥授粉前后花粉和乳突细胞的超微结构进行了观察。发现花粉和柱头乳突细胞一些未经报道的超微结构特征,可能与拟南芥花粉和乳突细胞的识别及花粉管生长相关:(1)成熟花粉中,电子透明的、体积较大的小液泡(直径200～1000nm)呈均匀分布。部分小液泡内含有多层膜状结构物质,推测可能是膜的一种储存形式,与花粉萌发时大量出现的小囊泡有关。(2)花粉萌发时,小液泡由均匀分布变为不均匀分布。(3)授粉前后的乳突细胞顶端和侧端的内壁上有明显的壁内突结构,粘附的花粉开始萌发时的乳突细胞壁内突处可观察到直径50～100nm的小泡存在,表明拟南芥乳突细胞具有一定的分泌功能。

We investigated the ultrastructures of pollen grains and stigmatic papillae cells before and after pollination of Arabidopsis by using transmission electron microscopy. We found some structures, not being reported previously, may be involved in the interaction between the pollen grains/tubes and the papillae cells. （1） In mature pollen grains, the electron-transparent vacuoles 200-1 000 nm are even distribution in cytosol, and some membrane structures are present in those vacuoles, especially the pollen before hydration. （2） The even distribution of vacuoles is changed to polar distribution after pollen germination. （3） Wall ingrowths were found in the inner wall of the papillar cells before and after pollination, which means papillar cells maybe function actively in pollination of Arabidopsis.