title: Lipoxygenase6-dependent oxylipin synthesis in roots is required for abiotic and biotic stress resistance of Arabidopsis.
abstract: Jasmonates are oxylipin signals that play important roles in the development of fertile flowers and in defense against pathogens and herbivores in leaves. The aim of this work was to understand the synthesis and function of jasmonates in roots. Grafting experiments with a jasmonate-deficient mutant demonstrated that roots produce jasmonates independently of leaves, despite low expression of biosynthetic enzymes. Levels of 12-oxo-phytodienoic acid, jasmonic acid, and its isoleucine derivative increased in roots upon osmotic and drought stress. Wounding resulted in a decrease of preformed 12-oxo-phytodienoic acid concomitant with an increase of jasmonic acid and jasmonoyl-isoleucine. 13-Lipoxygenases catalyze the first step of lipid oxidation leading to jasmonate production. Analysis of 13-lipoxygenase-deficient mutant lines showed that only one of the four 13-lipoxygenases, LOX6, is responsible and essential for stress-induced jasmonate accumulation in roots. In addition, LOX6 was required for production of basal 12-oxo-phytodienoic acid in leaves and roots. Loss-of-function mutants of LOX6 were more attractive to a detritivorous crustacean and more sensitive to drought, indicating that LOX6-derived oxylipins are important for the responses to abiotic and biotic factors.
authors: Department of Pharmaceutical Biology, Julius-von-Sachs-Institute for Biosciences, Biocenter, University of Wuerzburg, 97082 Wuerzburg, Germany.
authors: Wiebke
authors: W
authors: Grebner
authors: Nadja E
authors: NE
authors: Stingl
authors: Ayla
authors: A
authors: Oenel
authors: Martin J
authors: MJ
authors: Mueller
authors: Susanne
authors: S
authors: Berger
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000201:enzymology* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D003445:Crustacea / Q000502:physiology; D003517:Cyclopentanes / Q000378:metabolism; D055864:Droughts; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005247:Feeding Behavior; D008084:Lipoxygenase / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009995:Osmosis; D054883:Oxylipins / Q000378:metabolism*; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D054883:Oxylipins; C025999:12-oxophytodienoic acid; C011006:jasmonic acid; C117433:13-lipoxygenase; D008084:Lipoxygenase