CATALASE2 Coordinates SA-Mediated Repression of Both Auxin Accumulation and JA Biosynthesis in Plant Defenses.
Plants defend against pathogen attack by modulating auxin signaling and activating the salicylic acid (SA) and jasmonic acid (JA) signaling pathways. SA and JA act antagonistically in resistance to specific pathogen types, yet how plants coordinate these phytohormones remains elusive. Here we report that biotrophic-pathogen-induced SA accumulation dampens both auxin and JA synthesis by inhibiting CATALASE2 (CAT2) activity in the model plant Arabidopsis. SA suppression of CAT2 results in increased H2O2levels and subsequent sulfenylation of tryptophan synthetase β subunit 1, thus depleting the auxin biosynthetic precursor tryptophan. In addition, we find that CAT2 promotes JA biosynthesis by facilitating direct interaction of the JA biosynthetic enzymes ACX2 and ACX3, and thus SA repression of CAT2 inhibits JA accumulation. As such, the cat2-1 mutant exhibits increased resistance to biotrophic pathogens and increased susceptibility to necrotrophic pathogens. Our study illustrates how CAT2 coordinates SA repression of auxin accumulation and JA biosynthesis in plant defense.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Hong-Mei
HM
Yuan
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Wen-Cheng
WC
Liu
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China. Electronic address: yingtlu@whu.edu.cn.
Ying-Tang
YT
Lu
D042962:Acyl-CoA Oxidase / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002374:Catalase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D007210:Indoleacetic Acids; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; D006861:Hydrogen Peroxide; C490276:CAT2 protein, Arabidopsis; D002374:Catalase; C505728:ACX2 protein, Arabidopsis; C467988:ACX3 protein, Arabidopsis; D042962:Acyl-CoA Oxidase; D020156:Salicylic Acid
ACX; Arabidopsis; CAT2; H(2)O(2); JA; SA; auxin; biotrophic pathogen; necrotrophic pathogen; sulfenylation