title: Overexpression of Rat Neurons Nitric Oxide Synthase in Rice Enhances Drought and Salt Tolerance.
abstract: Nitric oxide (NO) has been shown to play an important role in the plant response to biotic and abiotic stresses in Arabidopsis mutants with lower or higher levels of endogenous NO. The exogenous application of NO donors or scavengers has also suggested an important role for NO in plant defense against environmental stress. In this study, rice plants under drought and high salinity conditions showed increased nitric oxide synthase (NOS) activity and NO levels. Overexpression of rat neuronal NO synthase (nNOS) in rice increased both NOS activity and NO accumulation, resulting in improved tolerance of the transgenic plants to both drought and salt stresses. nNOS-overexpressing plants exhibited stronger water-holding capability, higher proline accumulation, less lipid peroxidation and reduced electrolyte leakage under drought and salt conditions than wild rice. Moreover, nNOS-overexpressing plants accumulated less H2O2, due to the observed up-regulation of OsCATA, OsCATB and OsPOX1. In agreement, the activities of CAT and POX were higher in transgenic rice than wild type. Additionally, the expression of six tested stress-responsive genes including OsDREB2A, OsDREB2B, OsSNAC1, OsSNAC2, OsLEA3 and OsRD29A, in nNOS-overexpressing plants was higher than that in the wild type under drought and high salinity conditions. Taken together, our results suggest that nNOS overexpression suppresses the stress-enhanced electrolyte leakage, lipid peroxidation and H2O2 accumulation, and promotes proline accumulation and the expression of stress-responsive genes under stress conditions, thereby promoting increased tolerance to drought and salt stresses.
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Wen-Shu
authors.initials: WS
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Zheng-Wei
authors.initials: ZW
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Tong-Tong
authors.initials: TT
authors.lastname: Han
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Ying-Tang
authors.initials: YT
authors.lastname: Lu
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D055864:Droughts; D004789:Enzyme Activation; D015870:Gene Expression; D009569:Nitric Oxide / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D055049:Salt Tolerance / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D052248:Nitric Oxide Synthase Type I