title: Singlet oxygen is the major reactive oxygen species involved in photooxidative damage to plants.
abstract: Reactive oxygen species act as signaling molecules but can also directly provoke cellular damage by rapidly oxidizing cellular components, including lipids. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry-based quantitative method that allowed us to discriminate between free radical (type I)- and singlet oxygen ((1)O(2); type II)-mediated lipid peroxidation (LPO) signatures by using hydroxy fatty acids as specific reporters. Using this method, we observed that in non-photosynthesizing Arabidopsis (Arabidopsis thaliana) tissues, nonenzymatic LPO was almost exclusively catalyzed by free radicals both under normal and oxidative stress conditions. However, in leaf tissues under optimal growth conditions, (1)O(2) was responsible for more than 80% of the nonenzymatic LPO. In Arabidopsis mutants favoring (1)O(2) production, photooxidative stress led to a dramatic increase of (1)O(2) (type II) LPO that preceded cell death. Furthermore, under all conditions and in mutants that favor the production of superoxide and hydrogen peroxide (two sources for type I LPO reactions), plant cell death was nevertheless always preceded by an increase in (1)O(2)-dependent (type II) LPO. Thus, besides triggering a genetic cell death program, as demonstrated previously with the Arabidopsis fluorescent mutant, (1)O(2) plays a major destructive role during the execution of reactive oxygen species-induced cell death in leaf tissues.
authors.affiliation: Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie Environnementale et Biotechnologie, Laboratoire de Ecophysiologie Moléculaire des Plantes, Saint Paul lez Durance, France. ctriantaphylid@cea.fr
authors.forename: Christian
authors.initials: C
authors.lastname: Triantaphylidès
authors.forename: Markus
authors.initials: M
authors.lastname: Krischke
authors.forename: Frank Alfons
authors.initials: FA
authors.lastname: Hoeberichts
authors.forename: Brigitte
authors.initials: B
authors.lastname: Ksas
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gresser
authors.forename: Michel
authors.initials: M
authors.lastname: Havaux
authors.forename: Frank
authors.initials: F
authors.lastname: Van Breusegem
authors.forename: Martin Johannes
authors.initials: MJ
authors.lastname: Mueller
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death; D002851:Chromatography, High Pressure Liquid; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects*; D009154:Mutation; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D026082:Singlet Oxygen / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism / Q000494:pharmacology; D053719:Tandem Mass Spectrometry
chemical_list: D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D018749:RNA, Plant; D013481:Superoxides; D026082:Singlet Oxygen; D006861:Hydrogen Peroxide