CRK2 and C-terminal Phosphorylation of NADPH Oxidase RBOHD Regulate Reactive Oxygen Species Production in Arabidopsis
Sachie Kimura, Kerri Hunter, Lauri Vaahtera, Huy Cuong Tran, Matteo Citterico, Aleksia Vaattovaara, Anne Rokka, Sara Christina Stolze, Anne Harzen, Lena Meißner, Maya Wilkens, Thorsten Hamann, Masatsugu Toyota, Hirofumi Nakagami, Michael Wrzaczek
Abstract
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 Ala reduced ROS production in Arabidopsis. Phylogenetic analysis suggests that phospho-sites in the 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 and that CRK2 is an important element in regulating microbe-associated molecular pattern-triggered ROS production.