title: Effect of constitutive expression of bacterial phytoene desaturase CRTI on photosynthetic electron transport in Arabidopsis thaliana.
abstract: The constitutive expression of the bacterial carotene desaturase (CRTI) in Arabidopsis thaliana leads to increased susceptibility of leaves to light-induced damage. Changes in the photosynthetic electron transport chain rather than alterations of the carotenoid composition in the antenna were responsible for the increased photoinhibition. A much higher level of superoxide/hydrogen peroxide was generated in the light in thylakoid membranes from the CRTI expressing lines than in wild-type while the level of singlet oxygen generation remained unchanged. The increase in reactive oxygen species was related to the activity of plastid terminal oxidase (PTOX) since their generation was inhibited by the PTOX-inhibitor octyl gallate, and since the protein level of PTOX was increased in the CRTI-expressing lines. Furthermore, cyclic electron flow was suppressed in these lines. We propose that PTOX competes efficiently with cyclic electron flow for plastoquinol in the CRTI-expressing lines and that it plays a crucial role in the control of the reduction state of the plastoquinone pool.
authors.affiliation: Commissariat à l'Energie Atomique (CEA) Saclay, iBiTec-S, CNRS UMR 8221, Service de Bioénergétique, Biologie Structurale et Mécanisme, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Denise
authors.initials: D
authors.lastname: Galzerano
authors.affiliation: Commissariat à l'Energie Atomique (CEA) Saclay, iBiTec-S, CNRS UMR 8221, Service de Bioénergétique, Biologie Structurale et Mécanisme, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Feilke
authors.affiliation: Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schaub
authors.affiliation: Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Beyer
authors.affiliation: Commissariat à l'Energie Atomique (CEA) Saclay, iBiTec-S, CNRS UMR 8221, Service de Bioénergétique, Biologie Structurale et Mécanisme, 91191 Gif-sur-Yvette Cedex, France. Electronic address: anja.krieger-liszkay@cea.fr.
authors.forename: Anja
authors.initials: A
authors.lastname: Krieger-Liszkay
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D004579:Electron Transport / Q000235:genetics / Q000528:radiation effects; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D006861:Hydrogen Peroxide / Q000378:metabolism; D015151:Immunoblotting; D010084:Oxidation-Reduction / Q000528:radiation effects; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics / Q000528:radiation effects; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D030821:Plants, Genetically Modified; D010971:Plastoquinone / Q000031:analogs & derivatives / Q000378:metabolism; D026082:Singlet Oxygen / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D020524:Thylakoids / Q000378:metabolism / Q000528:radiation effects
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D002338:Carotenoids; D002734:Chlorophyll; D005707:Gallic Acid; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D010971:Plastoquinone; D026082:Singlet Oxygen; D013481:Superoxides; C016627:octyl gallate; C003165:plastoquinol; C022398:phytoene dehydrogenase; C405742:IM protein, Arabidopsis
keywords: A. thaliana; bacterial phytoene desaturase; photoinhibition; photosynthetic electron transport; plastid terminal oxidase; reactive oxygen species