title: The emerging roles of nitric oxide (NO) in plant mitochondria.
abstract: In recent years nitric oxide (NO) has been recognized as an important signal molecule in plants. Both, reductive and oxidative pathways and different subcellular compartments appear involved in NO production. The reductive pathway uses nitrite as substrate, which is exclusively generated by cytosolic nitrate reductase (NR) and can be converted to NO by the same enzyme. The mitochondrial electron transport chain is another site for nitrite to NO reduction, operating specifically when the normal electron acceptor, O(2), is low or absent. Under these conditions, the mitochondrial NO production contributes to hypoxic survival by maintaining a minimal ATP formation. In contrast, excessive NO production and concomitant nitrosative stress may be prevented by the operation of NO-scavenging mechanisms in mitochondria and cytosol. During pathogen attacks, mitochondrial NO serves as a nitrosylating agent promoting cell death; whereas in symbiotic interactions as in root nodules, the turnover of mitochondrial NO helps in improving the energy status similarly as under hypoxia/anoxia. The contribution of NO turnover during pathogen defense, symbiosis and hypoxic stress is discussed in detail.
authors: Department of Plant Physiology, University of Rostock, Albert Einstein Str 3, D-10859 Rostock, Germany. jagadis.kapuganti@uni-rostock.de
authors: Kapuganti J
authors: KJ
authors: Gupta
authors: Abir U
authors: AU
authors: Igamberdiev
authors: Girigowda
authors: G
authors: Manjunatha
authors: Shruthi
authors: S
authors: Segu
authors: Jose F
authors: JF
authors: Moran
authors: Bagyalakshmi
authors: B
authors: Neelawarne
authors: Hermann
authors: H
authors: Bauwe
authors: Werner M
authors: WM
authors: Kaiser
mesh_terms: D015687:Cell Hypoxia; D004579:Electron Transport; D008928:Mitochondria / Q000378:metabolism*; D008954:Models, Biological; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009572:Nitrite Reductases / Q000502:physiology; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000378:metabolism / Q000502:physiology; D010944:Plants / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D010940:Plant Proteins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D009572:Nitrite Reductases