title: Antagonistic effects of hydrogen peroxide and glutathione on acclimation to excess excitation energy in Arabidopsis.
abstract: The redox status of the quinone B (Q(B)) and plastoquinone (PQ) pools plays a key role in the cellular and systemic signalling processes that control acclimatory responses in plants. In this study, we demonstrate the effects of hydrogen peroxide and glutathione on acclimatory responses controlled by redox events in the proximity of the Q(B)-PQ pools. Our results suggest that the chloroplast is a sink for H2O2 and that, paradoxically, high concentrations of H2O2 in the chloroplast protect the photosynthetic apparatus and the plant cell from photoinhibition and photooxidative damage. Excess glutathione, however, caused an effect antagonistic to that observed for high H2O2. An explanation of this apparent paradox and a hypothetical redox-signalling model are suggested.
authors.affiliation: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Faculty of Forestry, Swedish University of Agricultural Sciences.
authors.forename: B
authors.initials: B
authors.lastname: Karpinska
authors.forename: G
authors.initials: G
authors.lastname: Wingsle
authors.forename: S
authors.initials: S
authors.lastname: Karpinski
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D060387:Ascorbate Peroxidases; D001692:Biological Transport; D004237:Diuron / Q000494:pharmacology; D004583:Electrons; D004734:Energy Metabolism; D005978:Glutathione / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010544:Peroxidases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins / Q000187:drug effects / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010971:Plastoquinone / Q000378:metabolism; D011809:Quinones / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D016877:Oxidants; D045322:Photosynthetic Reaction Center Complex Proteins; D011809:Quinones; D004237:Diuron; D006861:Hydrogen Peroxide; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D005978:Glutathione; D010971:Plastoquinone