胚珠发育的分子基础

MOLECULAR BASES OF OVULE DEVELOPMENT

胚珠作为胚囊的携带者，在植物的生殖过程中起重要作用。胚珠是种子的前身，它在受精后发育成种子。近年来通过诱变已创造出一些胚珠和胚囊发育异常的突变体，如ｓｉｎ１，ｂｅｌ，ｏｖｍ２，ｏｖｍ３。这几个突变体的表现型不但是珠被发育异常，而且胚囊不能形成或发育异常，最终结果是雌性不育。同时，已分别从蝶兰和矮牵牛的胚珠中分离出一批胚珠发育特异的基因，其中有关ＭＡＤＳＢｏｘ基因在胚珠形成和发育中的作用研究得比较清楚，基因转化工作证实胚珠的分化和形成受一类新的ＭＡＤＳＢｏｘ基因控制。

The ovule is the source of the embryo sac and the progenitor of the seed,which plays an important role on plant reproduction. A few mutants had been identified in recent years,such as sin1,bell,ovm2,ovm3,whose phenotypes show that both integuments and embryo sac develop abnormally,and these mutants are femalesterile. At the same time,some ovulespecific cDNA clones in Orchid and Petunia flowers had been isolated and among them MADS Box genes may be responsible for the ovule differentiation and formation. 