论文题目：A rice calmodulin-like protein OsCML27 participates in drought tolerance by fine-tuning OsRbohB-mediated ROS signaling
论文作者：Peng-Tao Shi, Ran Zhang, Xuan-Jie Wu, Zhe Zhang, Bin-Bin Li, Si- Lin Wang , Hao Chen,Xiu- Ni Fan, Wen-Ting Liu, Jingjing Wen, Kun-Ming Chen
论文摘要：Respiratory burst oxidase homolog (RBOH)–based ROS production was widely verified playing vital roles in plant stress responses; however, its inhibitory mechanism remains largely unknown. Here, we demonstrate that a calmodulin-like (CML) protein OsCML27 functions as a flexible brake of OsRbohB-mediated ROS production to regulate rice drought tolerance via an OsMRLK63-OsCML27-OsRbohB module. OsCML27 negatively regulates drought tolerance of rice where the overexpression lines showed a faster water loss rate and a lower survival rate under drought, while the oscml27 mutants exhibited a slower dehydration rate and a slightly lower survival rate as compared to wild type. OsCML27 can interact with and be phosphorylated by a receptor-like kinase OsMRLK63 primarily at Ser11, and the phosphorylation level could be increased by drought. The phosphorylation by OsMRLK63 enhances OsCML27 stability, and OsCML27 inhibits ROS production by interacting with OsRbohB in the Ca2+-dependent manner. All these results reveal that OsCML27 integrates phosphorylation and Ca2+signals to regulate drought tolerance of rice by fine-tuning OsRbohB-mediated ROS signaling.
基于呼吸爆发氧化酶同源物（RBOH）的活性氧（ROS）产生被广泛证明在植物胁迫响应中扮演关键角色，但该ROS产生途径的抑制机制长期不清。本研究发现，一个类钙调蛋白OsCML27在OsRbohB介导的ROS释放中发挥着精巧“刹车”作用，通过OsMRLK63-OsCML27-OsRbohB模块调节水稻耐旱性。OsCML27负调控水稻耐旱性，其过表达植株失水快且在干旱下的存活率显著降低，而敲除突变体表现出较低的脱水速率及略低于野生型的存活率。OsCML27能够和类受体蛋白激酶OsMRLK63互作并被其磷酸化，磷酸化的主要位点是第11位的Ser，并且干旱胁迫能够增加该磷酸化水平。研究进一步发现，OsMRLK63对OsCML27的磷酸化能增强后者的蛋白稳定性，且OsCML27以Ca2+依赖的方式通过与OsRbohB互作而抑制ROS产生。总之，本研究揭示，OsCML27可整合磷酸化和Ca2+信号，通过精细调控OsRbohB介导的ROS信号而调节水稻耐旱性。
论文链接：https://www.science.org/doi/10.1126/sciadv.aee6303