title: Four 13-lipoxygenases contribute to rapid jasmonate synthesis in wounded Arabidopsis thaliana leaves: a role for lipoxygenase 6 in responses to long-distance wound signals.
abstract: Damage-inducible defenses in plants are controlled in part by jasmonates, fatty acid-derived regulators that start to accumulate within 30 s of wounding a leaf. Using liquid chromatography-tandem mass spectrometry, we sought to identify the 13-lipoxygenases (13-LOXs) that initiate wound-induced jasmonate synthesis within a 190-s timeframe in Arabidopsis thaliana in 19 single, double, triple and quadruple mutant combinations derived from the four 13-LOX genes in this plant. All four 13-LOXs were found to contribute to jasmonate synthesis in wounded leaves: among them LOX6 showed a unique behavior. The relative contribution of LOX6 to jasmonate synthesis increased with distance from a leaf tip wound, and LOX6 was the only 13-LOX necessary for the initiation of early jasmonate synthesis in leaves distal to the wounded leaf. Herbivory assays that compared Spodoptera littoralis feeding on the lox2-1 lox3B lox4A lox6A quadruple mutant and the lox2-1 lox3B lox4A triple mutant revealed a role for LOX6 in defense of the shoot apical meristem. Consistent with this, we found that LOX6 promoter activity was strong in the apical region of rosettes. The LOX6 promoter was active in and near developing xylem cells and in expression domains we term subtrichomal mounds.
authors.affiliation: Department of Plant Molecular Biology, University of Lausanne, Biophore, 1015, Lausanne, Switzerland.|School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 quai Ernest-Ansermet, CH-1211, Geneva 4, Switzerland.
authors.forename: Adeline
authors.initials: A
authors.lastname: Chauvin
authors.affiliation: Swiss Institute of Bioinformatics, University of Lausanne, Génopode, 1015, Lausanne, Switzerland.
authors.forename: Daniela
authors.initials: D
authors.lastname: Caldelari
authors.affiliation: School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 quai Ernest-Ansermet, CH-1211, Geneva 4, Switzerland.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Wolfender
authors.affiliation: Department of Plant Molecular Biology, University of Lausanne, Biophore, 1015, Lausanne, Switzerland.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Farmer
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000469:parasitology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D060434:Herbivory / Q000276:immunology; D007532:Isoleucine / Q000031:analogs & derivatives / Q000378:metabolism; D007700:Kinetics; D008084:Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism*; D018515:Plant Leaves / Q000201:enzymology* / Q000469:parasitology; D011401:Promoter Regions, Genetic / Q000235:genetics; D015398:Signal Transduction; D018411:Spodoptera / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; C525049:JAS1 protein, Arabidopsis; D009687:Nuclear Proteins; D054883:Oxylipins; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; C011006:jasmonic acid; C117433:13-lipoxygenase; D008084:Lipoxygenase