title: Phytochrome-mediated regulation of plant respiration and photorespiration.
abstract: The expression of genes encoding various enzymes participating in photosynthetic and respiratory metabolism is regulated by light via the phytochrome system. While many photosynthetic, photorespiratory and some respiratory enzymes, such as the rotenone-insensitive NADH and NADPH dehydrogenases and the alternative oxidase, are stimulated by light, succinate dehydrogenase, subunits of the pyruvate dehydrogenase complex, cytochrome oxidase and fumarase are inhibited via the phytochrome mechanism. The effect of light, therefore, imposes limitations on the tricarboxylic acid cycle and on the mitochondrial electron transport coupled to ATP synthesis, while the non-coupled pathways become activated. Phytochrome-mediated regulation of gene expression also creates characteristic distribution patterns of photosynthetic, photorespiratory and respiratory enzymes across the leaf generating different populations of mitochondria, either enriched by glycine decarboxylase (in the upper part) or by succinate dehydrogenase (in the bottom part of the leaf).
authors.affiliation: Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada, A1B 3X9.
authors.forename: Abir U
authors.initials: AU
authors.lastname: Igamberdiev
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Eprintsev
authors.forename: Dmitry N
authors.initials: DN
authors.lastname: Fedorin
authors.forename: Vasily N
authors.initials: VN
authors.lastname: Popov
mesh_terms: D019069:Cell Respiration; D002952:Citric Acid Cycle; D004579:Electron Transport; D018506:Gene Expression Regulation, Plant; D050841:Glycine Dehydrogenase (Decarboxylating) / Q000378:metabolism / Q000502:physiology; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D024101:Mitochondrial Proteins / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010788:Photosynthesis; D010834:Phytochrome / Q000378:metabolism / Q000502:physiology*; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects; D010940:Plant Proteins / Q000378:metabolism; D010944:Plants / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D013385:Succinate Dehydrogenase / Q000378:metabolism / Q000502:physiology; D000099188:Alternative Oxidase
chemical_list: D050841:Glycine Dehydrogenase (Decarboxylating); D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010834:Phytochrome; D010940:Plant Proteins; D013385:Succinate Dehydrogenase; D000099188:Alternative Oxidase
keywords: alternative oxidase; electron transport; glycine decarboxylase; mitochondria; photorespiration; phytochrome; succinate dehydrogenase