title: The FLS2-associated kinase BIK1 directly phosphorylates the NADPH oxidase RbohD to control plant immunity.
abstract: The Arabidopsis immune receptor FLS2 senses the bacterial flagellin epitope flg22 to activate transient elevation of cytosolic calcium ions, production of reactive oxygen species (ROS), and other signaling events to coordinate antimicrobial defenses, such as stomatal closure that limits bacterial invasion. However, how FLS2 regulates these signaling events remains largely unknown. Here we show that the receptor-like cytoplasmic kinase BIK1, a component of the FLS2 immune receptor complex, not only positively regulates flg22-triggered calcium influx but also directly phosphorylates the NADPH oxidase RbohD at specific sites in a calcium-independent manner to enhance ROS generation. Furthermore, BIK1 and RbohD form a pathway that controls stomatal movement in response to flg22, thereby restricting bacterial entry into leaf tissues. These findings highlight a direct role of the FLS2 complex in the regulation of RbohD-mediated ROS production and stomatal defense.
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Life Sciences, Peking University, Beijing 100871, China; National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Yu
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Zhaoyang
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xiangxiu
authors.initials: X
authors.lastname: Liang
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Zixu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: Gaihong
authors.initials: G
authors.lastname: Cai
authors.affiliation: Center for Molecular Systems Biology and State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Gao
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center for Molecular Systems Biology and State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: National Institute of Biological Sciences, Beijing 102206, China.
authors.forename: She
authors.initials: S
authors.lastname: Chen
authors.affiliation: Center for Genome Biology and State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: jmzhou@genetics.ac.cn.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Zhou
mesh_terms: D017360:Arabidopsis / Q000276:immunology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species; C568857:AT5G47910 protein, Arabidopsis; D019255:NADPH Oxidases; D011494:Protein Kinases; C411853:FLS2 protein, Arabidopsis; C509522:BIK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases