title: The anoxic plant mitochondrion as a nitrite: NO reductase.
abstract: Under the conditions of oxygen deprivation, accumulating nitrite can be reduced in the mitochondrial electron transport chain forming free radical nitric oxide (NO). By reducing nitrite to NO, plant mitochondria preserve the capacity to oxidize external NADH and NADPH and retain a limited power for ATP synthesis complementing glycolytic ATP production. NO participates in O(2) balance in mitochondria by competitively inhibiting cytochrome c oxidase which can oxidize it to nitrite when oxygen concentration increases. Some of the NO escapes to the cytosol, where the efficient scavenging system involving non-symbiotic hemoglobin oxygenates NO to nitrate and supports continuous anaerobic turnover of nitrogen species.
authors.affiliation: Department of Plant Physiology, University of Rostock, Albert Einstein Str. 3, D-10859, Germany. igamberdiev@mun.ca
authors.forename: Kapuganti J
authors.initials: KJ
authors.lastname: Gupta
authors.forename: Abir U
authors.initials: AU
authors.lastname: Igamberdiev
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D016923:Cell Death; D015687:Cell Hypoxia; D003600:Cytosol / Q000378:metabolism; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010944:Plants / Q000201:enzymology / Q000378:metabolism*
chemical_list: D006454:Hemoglobins; D009573:Nitrites; D009243:NAD; D009569:Nitric Oxide; D009249:NADP; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; C034747:nitric-oxide reductase; D003576:Electron Transport Complex IV; D010100:Oxygen