Phosphorylation of OsRbohB by the protein kinase OsDMI3 promotes H_(2)O_(2) production to potentiate ABA responses in rice  

作　　者：Qingwen Wang Tao Shen Lan Ni Chao Chen Jingjing Jiang Zhenzhen Cui Shuang Wang Fengjuan Xu Runjiao Yan Mingyi Jiang 

机构地区：[1]College of Life Sciences,State Key Laboratory of Crop Genetics&Germplasm Enhancement and Utilization,Key Laboratory of Crop Physiology Ecology and Production Management,Ministry of Agriculture,Nanjing Agricultural University,Nanjing 210095,China

出　　处：《Molecular Plant》2023年第5期882-902,共21页分子植物（英文版）

基　　金：supported by the National Natural Science Foundation of China(31971824 and 32170316).

摘　　要：In rice, the Ca^(2+)/calmodulin-dependent protein kinase OsDMI3 is an important positive regulator of abscisic acid (ABA) signaling. In ABA signaling, H_(2)O_(2) is required for ABA-induced activation of OsDMI3, which in turn increase H_(2)O_(2) production. However, how OsDMI3 regulates H_(2)O_(2) production in ABA signaling remains unknown. Here we show that OsRbohB is the main NADPH oxidase involved in ABA-induced H_(2)O_(2) production and ABA-mediated physiological responses. OsDMI3 directly interacts with and phosphorylates OsRbohB at Ser-191, which is OsDMI3-mediated site-specific phosphorylation in ABA signaling. Further analyses revealed that OsDMI3-mediated OsRbohB Ser-191 phosphorylation positively regulates the activity of NADPH oxidase and the production of H_(2)O_(2) in ABA signaling, thereby enhancing the sensitivity of seed germination and root growth to ABA and plant tolerance to water stress and oxidative stress. Moreover, we discovered that the OsDMI3-mediated OsRbohB phosphorylation and H_(2)O_(2) production is dependent on the sucrose non-fermenting 1-related protein kinases SAPK8/9/10, which phosphorylate OsRbohB at Ser-140 in ABA signaling. Taken together, these results not only reveal an important regulatory mechanism that directly activates Rboh for ABA-induced H_(2)O_(2) production but also uncover the importance of this regulatory mechanism in ABA signaling.

关 键 词：abscisic acid Ca^(2+)/calmodulin-dependent protein kinase NADPH oxidases protein phosphorylation RICE 

分 类 号：Q94[生物学—植物学]