title: Redox regulation of photosynthetic gene expression.
abstract: Redox chemistry and redox regulation are central to the operation of photosynthesis and respiration. However, the roles of different oxidants and antioxidants in the regulation of photosynthetic or respiratory gene expression remain poorly understood. Leaf transcriptome profiles of a range of Arabidopsis thaliana genotypes that are deficient in either hydrogen peroxide processing enzymes or in low molecular weight antioxidant were therefore compared to determine how different antioxidant systems that process hydrogen peroxide influence transcripts encoding proteins targeted to the chloroplasts or mitochondria. Less than 10 per cent overlap was observed in the transcriptome patterns of leaves that are deficient in either photorespiratory (catalase (cat)2) or chloroplastic (thylakoid ascorbate peroxidase (tapx)) hydrogen peroxide processing. Transcripts encoding photosystem II (PSII) repair cycle components were lower in glutathione-deficient leaves, as were the thylakoid NAD(P)H (nicotinamide adenine dinucleotide (phosphate)) dehydrogenases (NDH) mRNAs. Some thylakoid NDH mRNAs were also less abundant in tAPX-deficient and ascorbate-deficient leaves. Transcripts encoding the external and internal respiratory NDHs were increased by low glutathione and low ascorbate. Regulation of transcripts encoding specific components of the photosynthetic and respiratory electron transport chains by hydrogen peroxide, ascorbate and glutathione may serve to balance non-cyclic and cyclic electron flow pathways in relation to oxidant production and reductant availability.
authors.affiliation: Centre for Plant Sciences, Faculty of Biology, University of Leeds, Leeds, UK.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Queval
authors.forename: Christine H
authors.initials: CH
authors.lastname: Foyer
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism; D001205:Ascorbic Acid / Q000235:genetics / Q000378:metabolism; D019069:Cell Respiration; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D004579:Electron Transport; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005978:Glutathione / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics*; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D060431:Thylakoid Membrane Proteins / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D029681:Arabidopsis Proteins; D045332:Photosystem II Protein Complex; D017382:Reactive Oxygen Species; D060431:Thylakoid Membrane Proteins; D006861:Hydrogen Peroxide; C555298:APXT protein, Arabidopsis; D060387:Ascorbate Peroxidases; C490276:CAT2 protein, Arabidopsis; D005978:Glutathione; D001205:Ascorbic Acid