TY - JOUR T1 - CRK2 and C-terminal phosphorylation of NADPH oxidase RBOHD regulate ROS production in Arabidopsis JF - bioRxiv DO - 10.1101/618819 SP - 618819 AU - Sachie Kimura AU - Kerri Hunter AU - Lauri Vaahtera AU - Huy Cuong Tran AU - Aleksia Vaattovaara AU - Anne Rokka AU - Sara Christina Stolze AU - Anne Harzen AU - Lena Meißner AU - Maya Wilkens AU - Thorsten Hamann AU - Masatsugu Toyota AU - Hirofumi Nakagami AU - Michael Wrzaczek Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/07/05/618819.abstract N2 - Reactive oxygen species (ROS) are important messengers in eukaryotic organisms and their production is tightly controlled. Active extracellular ROS production by NADPH oxidases in plants is triggered by receptor-like protein kinase (RLK)-dependent signaling networks. Here we show that the cysteine-rich RLK CRK2 kinase activity is required for plant growth and CRK2 exists in a preformed complex with the NADPH oxidase RBOHD in Arabidopsis. Functional CRK2 is required for the full elicitor-induced ROS burst and consequently the crk2 mutant is impaired in defense against the bacterial pathogen Pseudomonas syringae pv. tomato DC3000. Our work demonstrates that CRK2 regulates plant innate immunity. We identified in vitro CRK2-dependent phosphorylation sites in the C-terminal region of RBOHD. Phosphorylation of S703 RBOHD is enhanced upon flg22 treatment and substitution of S703 with alanine reduced ROS production in Arabidopsis. Phylogenetic analysis suggests that phospho-sites in C-terminal region of RBOHD are conserved throughout the plant lineage and between animals and plants. We propose that regulation of NADPH oxidase activity by phosphorylation of the C-terminal region might be an ancient mechanism. ER -