ABF转录因子在植物响应非生物胁迫中的作用

The Role of ABF Transcription Factors in Response to Abiotic Stress in Plant

非生物胁迫严重影响植物的生长发育及农作物的产量。植物激素脱落酸(ABA,abscisic acid)是植物响应非生物胁迫的重要信号分子,其介导的ABA信号途径在植物应答非生物胁迫过程中发挥关键作用,其中ABF(ABA-responsive element binding factors)转录因子在ABA信号途径中扮演着重要的角色。ABF转录因子是一类特异识别ABA响应元件(ABRE,ABA-responsive element)的碱性亮氨酸拉链蛋白,属于bZIP家族中的A亚族。它含有5个高度保守的结构域,C1、C2、C3、C4以及可以结合DNA序列的bZIP区域,这些保守结构域能够被蔗糖非酵解型蛋白激酶2(SnRK2,sucrose nonfermenting-1 related protein kinase 2)和钙依赖蛋白激酶(CDPK,calcium-dependent protein kinase)等多种蛋白激酶磷酸化,进而激活ABF蛋白的转录活性,使其参与ABA和逆境胁迫的调控表达。近年来,有较多研究发现不同物种中的ABF类转录因子在植物响应非生物胁迫的过程中具有重要作用。本文综述了ABF转录因子的结构特征及识别的顺式作用元件如G-ABRE、C-ABRE、"偶联元件3"(CE3,coupling element 3)等、调控修饰途径及其在盐、干旱、低温等非生物胁迫应答中的作用,并对未来ABF转录因子的研究方向进行展望,为通过调控ABF转录因子从而培育优良抗逆作物品种提供研究思路。

Abiotic stress seriously affects plant growth and destabilizes crop yield.The plant hormone abscisic acid(ABA)is an important signaling molecule for plants to respond to abiotic stress.The ABA signal pathway mediated by it plays a key role in the process of plant response to abiotic stress.Among them,ABF(ABA-responsive element binding factors)transcription factors play an important role in the ABA signal pathway.ABF transcription factor is a type of basic leucine zipper protein that specifically recognizes ABA-responsive element(ABRE),and they belong to the A subfamily of the bZIP family.ABF protein contains 5 highly conserved domains,C1,C2,C3,C4 and bZIP regions that can bind to DNA sequences.Besides,these conserved domains of ABF protein can be phosphorylated by many protein kinases,such as SnRK2(sucrose non-fermenting-1 related protein kinase 2)and CDPK(calcium dependent protein kinase),followed with the activation of the transcription activity of ABF protein.After finishing all the above steps,finally,they can participate in the regulation of ABA and stress expression.In recent years,many studies have found that ABF transcription factors in different species play an important role in response to abiotic stress in plants.This article reviews the structural characteristics of ABF transcription factors,the identified cis-acting elements such as G-ABRE,C-ABRE and CE3(coupling element 3),the regulatory modification pathway and their roles in response to abiotic stress such as salt,drought and cold.It also looks forward to the future research direction of ABF transcription factors,and provides research ideas for the cultivation of excellent stress-resistant crop varieties by regulating ABF transcription factors.