脱落酸信号转导途径在植物应对非生物胁迫响应中的作用  

The vital roles of abscisic acid signal transduction pathway in response to abiotic stress in plants

作　　者：张巧 王锦阳 董昳伶 肖旭腾 张敏 陈天池 吴月燕[1] ZHANG Qiao;WANG Jinyang;DONG Yiling;XIAO Xuteng;ZHANG Min;CHENG Tianchi;WU Yueyan(College of Biological and Environmental Sciences,Zhejiang Wanli University,Ningbo 315100,China;College of Fisheries and Life Science,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]浙江万里学院生物与环境学院,宁波315100 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《生命的化学》2021年第6期1160-1170,共11页Chemistry of Life

基　　金：宁波市科技重大专项(2019B10015)。

摘　　要：脱落酸(abscisic acid, ABA)是植物用来抵抗外界威胁的一种重要激素,它通过影响其信号通路中下游调控因子的转录和转录后修饰,控制植物对生物和非生物环境胁迫作出响应,从而增强植物的抗性。其核心反应首先是脱落酸受体接受脱落酸分子信号后,变构抑制蛋白磷酸酶2C(protein phosphatase 2C, PP2C)的活性,从而减轻或消除PP2C对蔗糖非发酵相关蛋白激酶2(sucrose non-fermented related protein kinase 2, SnRK2)的抑制,增强SnRK2激酶对底物蛋白的磷酸化来调节植物脱落酸的总体反应。其次,当感知到外界威胁时植物通过激活编码脱落酸生物合成酶基因的表达,促进脱落酸的生物合成和积累,从而激活脱落酸信号通路中下游胚胎发育晚期丰富蛋白(late embryogenesis abundant proteins, LEA)的表达,增多的LEA蛋白可以保护细胞膜的稳定性从而增进植物的抗逆性。另外,脱落酸在触发保卫细胞气孔关闭方面也起关键作用,脱落酸可以调节细胞离子通量,介导气孔闭合,减少水分流失。Abscisic acid(ABA) is an important hormone for plants to resist external threats. Through its influence on the transcription and post-transcription modifications of the downstream components of ABA signal pathway, ABA enhances the ability of plants to survive in abiotic and biotic stresses. Here we try to describe these processes with three aspects. Firstly, ABA receptor after binding ABA inhibits the allosteric activity of protein phosphatase 2C(PP2C), and subsequently reduce or eliminate PP2C inhibition to sucrose non-fermented related protein kinase 2(SnRK2) and the phosphorylation of downstream targets SnRK2 substrates so that enhance plant stress resistance. Secondly, when perceived external threats plants will stimulate the biosynthesis and accumulation of ABA by activating the genes encoding ABA biosynthesis enzymes. The elevated ABA could then upregulate the expression of late embryogenesis abundant proteins(LEA), which keep cell membrane stability to alleviate damage to plants under adverse conditions. In addition, ABA plays pivotal roles in triggering stomatal closure of guard cells, ABA can regulate cell ion flux, mediate stomatal closure and reduce water loss.

关 键 词：非生物性胁迫 脱落酸 信号转导 代谢 

分 类 号：Q945.78[生物学—植物学]