title: Nitric oxide induces the alternative oxidase pathway in Arabidopsis seedlings deprived of inorganic phosphate.
abstract: Phosphate starvation compromises electron flow through the cytochrome pathway of the mitochondrial electron transport chain, and plants commonly respond to phosphate deprivation by increasing flow through the alternative oxidase (AOX). To test whether this response is linked to the increase in nitric oxide (NO) production that also increases under phosphate starvation, Arabidopsis thaliana seedlings were grown for 15 d on media containing either 0 or 1mM inorganic phosphate. The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia. Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype. The NO donor S-nitrosoglutathione rescued the growth phenotype of the nia mutants under phosphate deprivation to some extent, and it also increased the respiratory capacity of AOX. It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions.
authors.affiliation: Department of Plant Sciences, University of Oxford, South Park Road, Oxford OX1 3RB, UK Institute of Agrobiotechnology, IdAB-CSIC-Public University of Navarre-Government of Navarre, Avda. Pamplona 123, E-31192, Mutilva, Navarre, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Royo
authors.affiliation: Institute of Agrobiotechnology, IdAB-CSIC-Public University of Navarre-Government of Navarre, Avda. Pamplona 123, E-31192, Mutilva, Navarre, Spain.
authors.forename: Jose F
authors.initials: JF
authors.lastname: Moran
authors.affiliation: Department of Plant Sciences, University of Oxford, South Park Road, Oxford OX1 3RB, UK jagadis.kapuganti@plants.ox.ac.uk jgk@nipgr.ac.in george.ratcliffe@plants.ox.ac.uk.
authors.forename: R George
authors.initials: RG
authors.lastname: Ratcliffe
authors.affiliation: Department of Plant Sciences, University of Oxford, South Park Road, Oxford OX1 3RB, UK National Institute of Plant Genome Research, Aruna Asaf Ali Marg, Jawaharlal Nehru University, New Delhi, Delhi 110067, India jagadis.kapuganti@plants.ox.ac.uk jgk@nipgr.ac.in george.ratcliffe@plants.ox.ac.uk.
authors.forename: Kapuganti J
authors.initials: KJ
authors.lastname: Gupta
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D004790:Enzyme Induction; D018506:Gene Expression Regulation, Plant; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D050901:Nitrate Reductase / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D000099188:Alternative Oxidase
chemical_list: D024101:Mitochondrial Proteins; D050901:Nitrate Reductase; D009569:Nitric Oxide; D010088:Oxidoreductases; D010710:Phosphates; D010940:Plant Proteins; D013481:Superoxides; D000099188:Alternative Oxidase
keywords: Alternative oxidase; Arabidopsis thaliana; inorganic phosphate; nitric oxide; phosphate stress; reactive oxygen species; respiration.