ANAC092参与调控花药发育的功能初探

摘要

NAC家族转录因子是高等植物特有的一类转录因子,功能广泛,这类蛋白在植物次生生长、细胞分裂、植物衰老、尤其在激素和信号途径起关键调控作用.ANAC092已报道参与侧根发育,并与衰老相关.为研究ANAC092基因在花药发育过程中的功能,文章构建了拟南芥ANA C09启动子的GUS载体,结合原位杂交分析结果表明,ANAC092在花药发育过程中时序性表达,在花药发育的8～11期绒毡层表达,其中在9～10期的表达量达到最高值,与AMS(Aborted microspores)的表达时期有重合.构建ANAC092过表达体系,筛选出转基因纯合株系.与野生型相比,过表达ANA C092转基因植株中花粉数量减少,花粉粒的长度增加.qRT-PCR结果表明,过表达株系中与花粉发育相关的基因SPL、EMS1、DYT1、AMS的表达量上调.结合生物信息学分析表明,ANAC092启动子序列中有7个AMS的结合位点,因此推测ANAC092可能位于AMS的下游而参与花药发育过程.%NAC family is a class of transcription factors that have been typically found in plant with various functions.This type of genes plays a key regulatory role in secondary plant growth,cell division,senescence,especially in the hormone and signaling pathways.ANAC092 was reported to function in relation to lateral root development and senescence.The promoter and in situ hybridization analyses showed that ANAC092 was expressed temporally in the process of anther development.The gene was expressed in tapetum at stages 8-11 of anther development and reached the highest amount at stages 9-10,which was overlapped with the expression period of AMS (Aborted microspores).In this study,we constructed ANAC092 over-expression system,and identified homozygous transgenic lines.Compared with the wild type,the number of pollen grains in the transgenic line was decreased significantly,but the length of pollen grain was increased,qRT-PCR analysis showed that the expression of genes related to pollen development,e.g.,SPL,EMS1,DYT1,and AMS was increased in the over-expression plants.Bioinformatics results showed that ANAC092 promoter sequence possessed seven AMS binding sites.All the results showed that ANAC092 is possibly located in the downstream of AMS and plays an important role in the process of pollen development.