OXI1 kinase is necessary for oxidative burst-mediated signalling in Arabidopsis

• Published in: Nature Vol. 427; no. 6977; pp. 858 - 861
• Main Authors: Rentel, Maike C, Hirt, Heribert, Lecourieux, David, Ouaked, Fatma, Usher, Sarah L, Petersen, Lindsay, Okamoto, Haruko, Knight, Heather, Peck, Scott C, Grierson, Claire S, Knight, Marc R
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 26.02.2004; Nature Publishing Group
• Subjects: active oxygen species; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis - parasitology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological and medical sciences; Cellulase - metabolism; Enzyme Activation - drug effects; Enzyme Induction - drug effects; Enzymes; Eukaryotes; Flowers & plants; Fundamental and applied biological sciences. Psychology; Genes; Genes, Reporter; Genetic Complementation Test; Hydrogen Peroxide - metabolism; Hydrogen Peroxide - pharmacology; Life Sciences; MAP Kinase Signaling System - drug effects; Metabolism; Metabolism. Physicochemical requirements; Mitogen-Activated Protein Kinase Kinases - metabolism; Mitogen-Activated Protein Kinases - metabolism; Molecular biology; MPK3 protein; MPK6 protein; OXI1 gene; Phytophthora - physiology; Plant Diseases - genetics; Plant Diseases - parasitology; Plant physiology and development; Plant Roots - enzymology; Plant Roots - growth & development; Plant Roots - metabolism; Protein Serine-Threonine Kinases - genetics; Protein Serine-Threonine Kinases - metabolism; Proteins; Reactive Oxygen Species - metabolism; Respiratory Burst; RNA, Messenger - genetics; RNA, Messenger - metabolism; Vegetal Biology; Oxidative stress; Enzyme; Transferases; Gene expression; Free radical; Arabidopsis thaliana; Signal transduction; Enzymatic activity; Gene; Cruciferae; Kinase; Dicotyledones; Angiospermae; Spermatophyta; Eucaryotes; plante; Stress Response
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature02353

Active oxygen species (AOS) generated in response to stimuli and during development can function as signalling molecules in eukaryotes, leading to specific downstream responses. In plants these include such diverse processes as coping with stress (for example pathogen attack, wounding and oxygen deprivation), abscisic-acid-induced guard-cell closure, and cellular development (for example root hair growth). Despite the importance of signalling via AOS in eukaryotes, little is known about the protein components operating downstream of AOS that mediate any of these processes. Here we show that expression of an Arabidopsis thaliana gene (OXI1) encoding a serine/threonine kinase is induced in response to a wide range of H2O2-generating stimuli. OXI1 kinase activity is itself also induced by H2O2 in vivo. OXI1 is required for full activation of the mitogen-activated protein kinases (MAPKs) MPK3 and MPK6 after treatment with AOS or elicitor and is necessary for at least two very different AOS-mediated processes: basal resistance to Peronospora parasitica infection, and root hair growth. Thus, OXI1 is an essential part of the signal transduction pathway linking oxidative burst signals to diverse downstream responses.