小柯机器人

美国密歇根大学Libo Shan等研究人员合作发现，DGK5介导的PA爆发的双重磷酸化调节植物免疫中的ROS。相关论文于2024年1月19日在线发表在《细胞》杂志上。

研究人员发现拟南芥二酰甘油激酶5（DGK5）调控植物模式触发免疫（PTI）和效应触发免疫（ETI）。模式识别受体（PRR）相关激酶BIK1会使DGK5在Ser-506处磷酸化，导致磷脂酸（PA）快速爆发并激活植物免疫，而PRR激活的细胞内MPK4会使DGK5在Thr-446处磷酸化，从而抑制DGK5的活性和PA的产生，导致植物免疫减弱。PA与NADPH氧化酶RESPIRATORY BURST OXIDASE HOMOLOG D（RBOHD）结合并使其稳定，从而调节植物PTI和ETI中活性氧（ROS）的产生及其增效作用。

这些数据表明，PRR激活的BIK1和MPK4对DGK5的不同磷酸化平衡了细胞PA暴发的平衡，而PA暴发调节ROS的产生，进而协调植物免疫的两个分支。

据介绍，PA和ROS是介导后生动物和植物中各种信号转导过程的重要细胞信使。在免疫诱导过程中，PA的平衡如何受到严格调控并与ROS信号交织在一起仍是一个谜。

附：英文原文

Title: Dual phosphorylation of DGK5-mediated PA burst regulates ROS in plant immunity

Author: Liang Kong, Xiyu Ma, Chao Zhang, Sung-Il Kim, Bo Li, Yingpeng Xie, In-Cheol Yeo, Hem Thapa, Sixue Chen, Timothy P. Devarenne, Teun Munnik, Ping He, Libo Shan

Issue&Volume: 2024-01-19

Abstract: Phosphatidic acid (PA) and reactive oxygen species (ROS) are crucial cellular messengersmediating diverse signaling processes in metazoans and plants. How PA homeostasisis tightly regulated and intertwined with ROS signaling upon immune elicitation remainselusive. We report here that Arabidopsis diacylglycerol kinase 5 (DGK5) regulates plant pattern-triggered immunity (PTI) andeffector-triggered immunity (ETI). The pattern recognition receptor (PRR)-associatedkinase BIK1 phosphorylates DGK5 at Ser-506, leading to a rapid PA burst and activationof plant immunity, whereas PRR-activated intracellular MPK4 phosphorylates DGK5 atThr-446, which subsequently suppresses DGK5 activity and PA production, resultingin attenuated plant immunity. PA binds and stabilizes the NADPH oxidase RESPIRATORYBURST OXIDASE HOMOLOG D (RBOHD), regulating ROS production in plant PTI and ETI, andtheir potentiation. Our data indicate that distinct phosphorylation of DGK5 by PRR-activatedBIK1 and MPK4 balances the homeostasis of cellular PA burst that regulates ROS generationin coordinating two branches of plant immunity.

DOI: 10.1016/j.cell.2023.12.030

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)01404-6