title: Nitric oxide supplementation alleviates ammonium toxicity in the submerged macrophyte Hydrilla verticillata (L.f.) Royle.
abstract: The likely protective effects of nitric oxide (NO) against ammonium toxicity were investigated in the submerged macrophyte Hydrilla verticillata. The plants were subjected to ammonium stress (3mM ammonium chloride) in the presence of sodium nitroprusside (SNP, 10 μM), an NO donor. Treatment with SNP significantly increased the NO content and partially reversed the ammonium-induced negative effects, including membrane damage and the decrease in levels of chlorophyll, malondialdehyde, glutathione and ascorbic acid. Further, SNP application increased the catalytic activities of ascorbate peroxidase, superoxide dismutase, guaiacol peroxidase, catalase and glutathione S-transferase, but decreased that of NADH-oxidase. Histochemical staining showed that SNP application caused a significant decrease in the levels of superoxides and hydrogen peroxide. In contrast, application of other breakdown products of SNP (10 μM sodium ferrocyanide, 10 μM sodium nitrite and 10 μM sodium nitrate) failed to show any protective effect. The results suggest that the increased intracellular NO, resulting from SNP application, improved the antioxidant capacity of H. verticillata plants in coping with ammonium-induced oxidative stress.
authors.affiliation: Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes and College of Environment, Hohai University, Xi Kang Road no. 1, JiangSu province, Nanjing 210098, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Song He
authors.initials: SH
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Pei Fang
authors.initials: PF
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Li
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology; D001205:Ascorbic Acid / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D005292:Ferricyanides / Q000008:administration & dosage / Q000494:pharmacology; D005982:Glutathione Transferase / Q000378:metabolism; D031321:Hydrocharitaceae / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D006861:Hydrogen Peroxide / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009566:Nitrates / Q000008:administration & dosage / Q000494:pharmacology; D009569:Nitric Oxide / Q000008:administration & dosage / Q000494:pharmacology*; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D000644:Quaternary Ammonium Compounds / Q000633:toxicity*; D012977:Sodium Nitrite / Q000008:administration & dosage / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005292:Ferricyanides; D009097:Multienzyme Complexes; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D013481:Superoxides; D002734:Chlorophyll; D009599:Nitroprusside; D009569:Nitric Oxide; D008315:Malondialdehyde; C031618:sodium nitrate; D006861:Hydrogen Peroxide; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D005982:Glutathione Transferase; D012977:Sodium Nitrite; D001205:Ascorbic Acid