肌动蛋白相关蛋白ARP5调控气孔发育的表观遗传机制研究  

Research on Epigenetic Mechanism of ARP5in Stomatal Development

作　　者：曹琳[1,2] 张弛[1,2] 安增选 朱炎[1,2] 

机构地区：[1]复旦大学生命科学学院植物科学研究所,上海200433 [2]复旦大学遗传工程国家重点实验室,上海200433

出　　处：《复旦学报（自然科学版）》2014年第4期535-542,549,共9页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金(31271374)资助项目

摘　　要：气孔是叶表皮分化的一类功能性细胞类型,是植物与外界进行气体交换的主要通道,对于植物在发育过程中适应环境起到重要的作用.气孔的发育受到复杂的转录调控,然而表观遗传机制是否参与到这一过程目前仍不清楚.ARP5是一类保守的肌动蛋白相关蛋白,在酵母和人类中参与染色质重塑.拟南芥arp5缺失突变体的叶片表现出气孔增多的表型.SPCH和MUTE是正向调控气孔发育的bHLH转录因子,RT-PCR分析显示其转录水平在arp5突变体背景下特异性地上调.ARP5可以在体外特异性地结合组蛋白变异体H2A.z.此外,H2A.z而非H3在SPCH和MUTE编码区的富集依赖ARP5的功能,表明拟南芥ARP5可能通过特异性地调控H2A.z的染色质分布影响SPCH和MUTE的转录水平.Stomata is composed of differentiated functional epidermal cells mediating the gas exchange between plants and the environment,and plays important roles in environment adaption during plant development.It is well known that stomata development is subjected to complex transcriptional regulations.However,the implication of epigenetic mechanism in stomata development is still not clear.ARP5 is a conserved Actin-related protein in eukaryotes,and is involved in chromatin remodeling in yeast and human cells.Arabidopsis mutants depleting of ARP5 activity display increased stomata in leaves.RT-PCR analysis revealed that bHLH transcription factor genes SPCHand MUTE,which positively regulate the stomata development,are up-regulated in arp5 mutants.The ARP5 protein can specifically binds histone variant H2 A.z in vitro.Moreover,the enrichment of H2 A.z,but not histone H3,within the SPCHand MUTEchromatin regions is dependent on ARP5 activity,suggesting that ARP5 likely regulates SPCHand MUTEexpression by modulating local H2 A.z distribution.

关 键 词：气孔 ARP5 H2A.z 表观遗传调控 bHLH转录因子 

分 类 号：Q945[生物学—植物学]