title: 2-cysteine peroxiredoxins and thylakoid ascorbate peroxidase create a water-water cycle that is essential to protect the photosynthetic apparatus under high light stress conditions.
abstract: Different peroxidases, including 2-cysteine (2-Cys) peroxiredoxins (PRXs) and thylakoid ascorbate peroxidase (tAPX), have been proposed to be involved in the water-water cycle (WWC) and hydrogen peroxide (H2O2)-mediated signaling in plastids. We generated an Arabidopsis (Arabidopsis thaliana) double-mutant line deficient in the two plastid 2-Cys PRXs (2-Cys PRX A and B, 2cpa 2cpb) and a triple mutant deficient in 2-Cys PRXs and tAPX (2cpa 2cpb tapx). In contrast to wild-type and tapx single-knockout plants, 2cpa 2cpb double-knockout plants showed an impairment of photosynthetic efficiency and became photobleached under high light (HL) growth conditions. In addition, double-mutant plants also generated elevated levels of superoxide anion radicals, H2O2, and carbonylated proteins but lacked anthocyanin accumulation under HL stress conditions. Under HL conditions, 2-Cys PRXs seem to be essential in maintaining the WWC, whereas tAPX is dispensable. By comparison, this HL-sensitive phenotype was more severe in 2cpa 2cpb tapx triple-mutant plants, indicating that tAPX partially compensates for the loss of functional 2-Cys PRXs by mutation or inactivation by overoxidation. In response to HL, H2O2- and photooxidative stress-responsive marker genes were found to be dramatically up-regulated in 2cpa 2cpb tapx but not 2cpa 2cpb mutant plants, suggesting that HL-induced plastid to nucleus retrograde photooxidative stress signaling takes place after loss or inactivation of the WWC enzymes 2-Cys PRX A, 2-Cys PRX B, and tAPX.
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Jasmin
authors: J
authors: Awad
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Henrik U
authors: HU
authors: Stotz
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Agnes
authors: A
authors: Fekete
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Markus
authors: M
authors: Krischke
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Cornelia
authors: C
authors: Engert
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Michel
authors: M
authors: Havaux
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.).
authors: Susanne
authors: S
authors: Berger
authors: Julius-von-Sachs-Institute of Biosciences, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany (J.A., H.U.S., A.F., M.K., C.E., S.B., M.J.M.); andBiologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265 Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique-Aix Marseille University, 13108 Saint-Paul-lez-Durance, France (M.H.) martin.mueller@biozentrum.uni-wuerzburg.de.
authors: Martin J
authors: MJ
authors: Mueller
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008027:Light / Q000009:adverse effects; D008954:Models, Biological; D009154:Mutation; D018384:Oxidative Stress; D054464:Peroxiredoxins / Q000378:metabolism*; D010788:Photosynthesis / Q000528:radiation effects; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D030821:Plants, Genetically Modified; D018087:Plastids / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D013312:Stress, Physiological; D020524:Thylakoids / Q000201:enzymology; D014867:Water / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D014867:Water; D002245:Carbon Dioxide; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D054464:Peroxiredoxins; D003545:Cysteine