title: Copper amine oxidase 8 regulates arginine-dependent nitric oxide production in Arabidopsis thaliana.
abstract: Nitric oxide (NO) is a key signaling molecule in plants, regulating a wide range of physiological processes. However, its origin in plants remains unclear. It can be generated from nitrite through a reductive pathway, notably via the action of the nitrate reductase (NR), and evidence suggests an additional oxidative pathway, involving arginine. From an initial screen of potential Arabidopsis thaliana mutants impaired in NO production, we identified copper amine oxidase 8 (CuAO8). Two cuao8 mutant lines displayed a decreased NO production in seedlings after elicitor treatment and salt stress. The NR-dependent pathway was not responsible for the impaired NO production as no change in NR activity was found in the mutants. However, total arginase activity was strongly increased in cuao8 knockout mutants after salt stress. Moreover, NO production could be restored in the mutants by arginase inhibition or arginine addition. Furthermore, arginine supplementation reversed the root growth phenotype observed in the mutants. These results demonstrate that CuAO8 participates in NO production by influencing arginine availability through the modulation of arginase activity. The influence of CuAO8 on arginine-dependent NO synthesis suggests a new regulatory pathway for NO production in plants.
authors.affiliation: Helmholtz Zentrum München, Department of Environmental Science, Institute of Biochemical Plant Pathology,D-85764 Neuherberg, Germany.
authors.forename: Felicitas
authors.initials: F
authors.lastname: Groß
authors.affiliation: Helmholtz Zentrum München, Department of Environmental Science, Institute of Biochemical Plant Pathology,D-85764 Neuherberg, Germany.
authors.forename: Eva-Esther
authors.initials: EE
authors.lastname: Rudolf
authors.affiliation: Forschungszentrum Jülich, Institute for Bio-and Geoscience, IBG-2, D-52428 Jülich, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Thiele
authors.affiliation: Helmholtz Zentrum München, Department of Environmental Science, Institute of Biochemical Plant Pathology, D-85764 Neuherberg, Germany.|Technical University Munich, Wissenschaftszentrum Weihenstephan, D-80333 München, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Durner
authors.affiliation: Helmholtz Zentrum München, Department of Environmental Science, Institute of Biochemical Plant Pathology,D-85764 Neuherberg, Germany.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Astier
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D001120:Arginine / Q000378:metabolism*; D007539:Isonicotinic Acids / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development*; D055049:Salt Tolerance
chemical_list: D007539:Isonicotinic Acids; D009569:Nitric Oxide; C077261:2,6-dichloroisonicotinic acid; D001120:Arginine; D006631:Amine Oxidase (Copper-Containing)
keywords: Arginase; arginine; copper amine oxidase; nitrate reductase; nitric oxide; nitric oxide production; plant.