植物学报 ›› 2011, Vol. 46 ›› Issue (4): 361-369.DOI: 10.3724/SP.J.1259.2011.00361

• 特邀综述 •    下一篇

始于质体/叶绿体的ABA信号通路

张大鹏*   

  1. 清华大学生命科学学院, 北京 100083
  • 收稿日期:2010-12-27 修回日期:2011-02-18 出版日期:2011-07-01 发布日期:2011-07-01
  • 通讯作者: 张大鹏
  • 基金资助:

    国家自然科学基金

An Abscisic Acid Signaling Pathway Starting from Plastid/Chloroplast

Dapeng Zhang*   

  1. School of Life Sciences, Tsinghua University, Beijing 100083, China
  • Received:2010-12-27 Revised:2011-02-18 Online:2011-07-01 Published:2011-07-01
  • Contact: Dapeng Zhang

摘要: 该文全面评述了植物激素脱落酸(ABA)受体的研究进展概况, 重点介绍细胞内ABA受体ABAR/镁螯合酶H亚基CHLH 对ABA信号感知和向下游转导的研究进展, 总结了ABAR介导的、起始于质体/叶绿体的ABA信号通路。ABAR是一个跨越叶绿体被膜的蛋白质, 其N-端和C-端暴露在细胞质中; ABAR在细胞质一侧的C-端部分与一组WRKY转录因子(WRKY18、WRKY40、WRKY60)相互作用。WRKY18、WRKY40和WRKY60是一组转录抑制因子。它们互相协作, 抑制下游重要的ABA信号调节子基因(如ABI4ABI5ABF4MYB2等)的表达, 从而负调节ABA信号通路。WRKY40是其中的核心调节子, WRKY18协助加强WRKY40对ABA信号的负调节。ABAR与ABA信号分子结合后, 可以刺激WRKY40从细胞核转移至细胞质, 促进ABAR与WRKY40的相互作用; 进而激发一种未知因子(或信号系统), 阻遏WRKY40的表达, 从而解除WRKY40对ABA响应基因转录的抑制, 最终实现ABA的生理效应。这些发现描述了一个从信号原初识别到下游基因表达的新的ABA信号通路。论文最后对未来该领域的研究方向进行了讨论。

Abstract: We give a brief review of the advances in studies of ABAR/CHLH-mediated abscisic acid (ABA) sensing and downstream signaling from early events starting from plastids/chloroplasts to downstream gene expression. ABAR spans the chloroplast envelope, and the cytosolic C terminus of ABAR interacts with a group of WRKY transcription factors, WRKY40, WRKY18, and WRKY60, which function as negative regulators of ABA signaling in seed germination and post-germination growth. WRKY40, a central negative regulator, inhibits the expression of ABA-responsive genes such as ABF4, ABI4, ABI5, and MYB2. In response to an ABA signal that recruits WRKY40 from the nucleus to the cytosol and promotes ABAR-WRKY40 interaction, ABAR relieves ABA-responsive genes of inhibition by repressing WRKY40 expression. These findings uncover a novel ABA signaling pathway from the early signaling events to downstream gene expression. We also discuss future studies needed to understand the complex ABAR-mediated ABA signaling pathway(s).