PYLs蛋白乙酰化修饰调控植物脱落酸信号转导和逆境响应的生物学机制

乙酰化修饰是一种重要的蛋白质翻译后修饰方式。近年来，在植物中发现大量的蛋白质发生乙酰化修饰，然而其生物学作用和调控机制尚不清楚。本项目前期研究发现，拟南芥中脱落酸（ABA）信号转导途径中的核心因子——PYLs受体家族成员PYR1和PYL1上多个保守的赖氨酸（K）位点发生乙酰化修饰；我们进而发现，PYR1蛋白上K59位点的乙酰化修饰阻断了PYR1与下游因子ABI1的蛋白互作，同时降低了拟南芥幼苗对ABA和干旱胁迫的反应。本项目拟在此基础上继续鉴定拟南芥中乙酰化修饰的PYLs蛋白及位点并检测其动态变化，解析PYLs各位点乙酰化修饰对植物响应ABA信号及抗逆性的影响，并探明介导PYLs乙酰化修饰的上游因子。本研究将阐明PYLs乙酰化修饰调控ABA信号转导及逆境响应的生物学机制，为耐逆农作物育种提供新的思路。

Acetylation is an important post-translational modification. Recent years, a large number of proteins were detected to be acetylated in plants, however, the biological role and regulatory mechanism kept unclear. In previous study, we found that PYR1 and PYL1, the PYLs receptor proteins in abscisic acid (ABA) signal transduction are acetylated at multiple conserved lysine (K) sites. We further found that acetylation of PYR1 at K59 abolishes its interaction with downstream factor protein phosphatase ABI1, and decreases the response of Arabidopsis seedlings to ABA and drought stress. Based on these findings, we will continue to identify the acetylated PYLs proteins and sites and examine their dynamic changes in Arabidopsis. We will analyze the effects of acetylated PYLs in ABA signal transduction and stress response. Finally, the upstream enzymes which catalyzing the acetylation of PYLs will be identified. Our work will elucidate the biological role of acetylation on PYLs in ABA signal transduction and stress response, and provide new idea to cultivate crops with high tolerance.