Jasmonic Acid Oxidase 2 Hydroxylates Jasmonic Acid and Represses Basal Defense and Resistance Responses against Botrytis cinerea Infection

作     者：Ekaterina Smirnova Ekaterina Smirnova

作者机构：Institut de Biologie Moléculaire des Plantes CNRS Université de Strasbourg Strasbourg France Laboratoire de Chimie Organique Synthétique Institut de Chimie Université de Strasbourg CNRS Strasbourg France 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2017年第10卷第9期

页      面：1159-1173页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 09[农学] 0906[农学-兽医学] 0901[农学-作物学] 0902[农学-园艺学] 

基　　金：supported by basic funding of CNRS grant ANR-12-BSV8-005 (JASMONOX) from the Agence Nationale de la Recherche to E.S. and Y.A. ldEx-2014-208e interdisciplinary grant to L.P. from Universite de Strasbourg and CNRS V.M. is recipient of a predoctoral fellowship from the Universite de Strasbourg and the Ministere de l'Enseignement Superieur et de la Recherche 

主　　题：2-oxoglutarate oxygenase jasmonic acid defense regulation hormone metabolism Botrytis 

摘      要：Jasmonates （JAs） orchestrate immune responses upon wound/herbivore injury or infection by necrotro- phic pathogens. Elucidation of catabolic routes has revealed new complexity in jasmonate metabolism. Two integrated pathways attenuate signaling by turning over the active hormone jasmonoyl-isoleucine （JA-Ile） through w-oxidation or deconjugation, and define an indirect route forming the derivative 12OH-JA. Here, we provide evidence for a second 12OH-JA formation pathway by direct jasmonic acid （JA） oxidation. Three jasmonic acid oxidases （JAOs） of the 2-oxoglutarate dioxygenase family catalyze spe- cific oxidation of JA to 12OH-JA, and their genes are induced by wounding or infection by the fungus Botrytis cinerea. JA02 exhibits the highest basal expression, and its deficiency in jao2 mutants strongly enhanced antifungal resistance. The resistance phenotype resulted from constitutive expression of antimi- crobial markers rather than from their higher induction in infected jao2 plants and could be reversed by ectopic expression of any of the three JAOs injao2. Elevated defense injao2 was dependent on the activity of JASMONATE RESPONSE 1 （JAR1） and CORONATINE-INSENSITIVE 1 （COI1） but was not correlated with erihanced JA-Ile accumulation. Instead, jao2 mutant lines displayed altered accumulation of several JA species in healthy and challenged plants, suggesting elevated metabolic flux through JA-Ile. Collectively, these data identify the missing enzymes hydroxylating JA and uncover an important metabolic diversion mechanism for repressing basal JA defense responses.