水稻OsMS2基因在花药发育中的功能分析

Functional Analysis of OsMS2 Gene Involved in Anther Development of Rice

拟南芥MS2(MALE STERILITY2)是一个调控花药花粉发育的关键基因。水稻OsMS2(Os03g07140)基因与拟南芥MS2的序列具有高度同源性。利用RNA干扰技术研究OsMS2基因在水稻花药发育过程中的功能。与野生型水稻相比,转基因植株营养生长阶段正常,但雄性育性降低。转基因植株雄性育性降低与RNA干扰引起的OsMS2基因表达水平降低有关。进一步对转基因植株花药进行细胞学观察,结果表明OsMS2基因表达水平的降低导致绒毡层细胞退化延迟,小孢子壁的形成出现异常。扫描电镜观察结果显示,小孢子壁光滑,不能形成正常的外壁。以上结果表明OsMS2基因在水稻花药发育过程中起重要作用。

The Arabidopsis MALE STERILITY2 （MS2） gene is required for anther and pollen development; sequence analysis indicated that the OsMS2 （OsO3g07140） gene shares high similarity with MS2 in Arabidopsis. Here, we describe the functional analysis of OsMS2 in rice anther development by the RNA interference approach. Transgenic lines with the introduced gene expressing double-stranded RNA with the OsMS2 DNA fragment grew normally during their vegetative phase but displayed reduced male fertility. The reduced fertility phenotypes were associated with down-regulated OsMS2 transcript level mediated by RNAi. Further cytological observations of the anthers of transgenic lines showed that knock-down of OsMS2 led to delayed tapetum degeneration and abnormal microspores in the anther. Scanning electron microscopy revealed that the microspores could not form normal exine. Thus, OsMS2 is an AtMS2homologue and plays an important role in rice anther development.