title: Formation of oxidized phosphatidylinositol and 12-oxo-phytodienoic acid containing acylated phosphatidylglycerol during the hypersensitive response in Arabidopsis.
abstract: Plant membranes are composed of a wide array of polar lipids. The functionality of these extends far beyond a pure structural role. Membrane lipids function as enzyme co-factors, establish organelle identity and as substrates for enzymes such as lipases and lipoxygenases. Enzymatic degradation or oxidation (enzymatic or non-enzymatic) of membrane lipids leads to the formation of a diverse group of bioactive compounds. Plant defense reactions provoked by pathogenic microorganisms are often associated with substantial modifications of the lipidome. In this study, we profiled changes in phospholipids during the hypersensitive response triggered by recognition of the bacterial effector protein AvrRpm1 in Arabidopsis thaliana. A simple and robust LC-MS based method for profiling plant lipids was designed to separate all the major species of glycerolipids extracted from Arabidopsis leaf tissue. The method efficiently separated several isobaric and near isobaric lipid species, which otherwise are difficult to quantify in direct infusion based profiling. In addition to the previously reported OPDA-containing galactolipids found to be induced during hypersensitive response in Arabidopsis, three OPDA-containing sulfoquinovosyl diacylglycerol species, one phosphatidylinositol species as well as two acylated OPDA-containing phosphatidylglycerol species were found to accumulate during the hypersensitive response in Arabidopsis. Our study confirms and extends on the notion that the hypersensitive response in Arabidopsis triggers a unique profile of Allene Oxide Synthase dependent oxidation of membrane lipids. Primary targets of this oxidation seem to be uncharged and anionic lipid species.
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
authors.forename: Anders K
authors.initials: AK
authors.lastname: Nilsson
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
authors.forename: Oskar N
authors.initials: ON
authors.lastname: Johansson
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Fahlberg
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
authors.forename: Feray
authors.initials: F
authors.lastname: Steinhart
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
authors.forename: Mikael B
authors.initials: MB
authors.lastname: Gustavsson
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Ellerström
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden. Electronic address: mats.andersson@bioenv.gu.se.
authors.forename: Mats X
authors.initials: MX
authors.lastname: Andersson
mesh_terms: D000215:Acylation; D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism* / Q000382:microbiology; D001426:Bacterial Proteins / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D010084:Oxidation-Reduction; D010715:Phosphatidylglycerols / Q000096:biosynthesis*; D010716:Phosphatidylinositols / Q000096:biosynthesis*; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: C502082:AvrRpm1 protein, Pseudomonas syringae; D001426:Bacterial Proteins; D005231:Fatty Acids, Unsaturated; D010715:Phosphatidylglycerols; D010716:Phosphatidylinositols; C025999:12-oxophytodienoic acid
keywords: 12-Oxo-phytodienoic acid; Arabidopside; Galactolipid; Hypersensitive response; Lipid profiling; Membrane lipid