title: Roles of NIA/NR/NOA1-dependent nitric oxide production and HY1 expression in the modulation of Arabidopsis salt tolerance.
abstract: Despite substantial evidence on the separate roles of Arabidopsis nitric oxide-associated 1 (NOA1)-associated nitric oxide (NO) production and haem oxygenase 1 (HY1) expression in salt tolerance, their integrative signalling pathway remains largely unknown. To fill this knowledge gap, the interaction network among nitrate reductase (NIA/NR)- and NOA1-dependent NO production and HY1 expression was studied at the genetic and molecular levels. Upon salinity stress, the majority of NO production was attributed to NIA/NR/NOA1. Further evidence confirmed that HY1 mutant hy1-100, nia1/2/noa1, and nia1/2/noa1/hy1-100 mutants exhibited progressive salt hypersensitivity, all of which were significantly rescued by three NO-releasing compounds. The salinity-tolerant phenotype and the stronger NO production in gain-of-function mutant of HY1 were also blocked by the NO synthetic inhibitor and scavenger. Although NO- or HY1-deficient mutants showed a compensatory mode of upregulation of HY1 or slightly increased NO production, respectively, during 2 d of salt treatment, downregulation of ZAT10/12-mediated antioxidant gene expression (cAPX1/2 and FSD1) was observed after 7 d of treatment. The hypersensitive phenotypes and stress-related genes expression profiles were differentially rescued or blocked by the application of NO- (in particular) or carbon monoxide (CO)-releasing compounds, showing a synergistic mode. Similar reciprocal responses were observed in the nia1/2/noa1/hy1-100 quadruple mutant, with the NO-releasing compounds exhibit the maximal rescuing responses. Overall, the findings present the combination of compensatory and synergistic modes, linking NIA/NR/NOA1-dependent NO production and HY1 expression in the modulation of plant salt tolerance.
authors.affiliation: College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Xie
authors.forename: Yu
authors.initials: Y
authors.lastname: Mao
authors.forename: Diwen
authors.initials: D
authors.lastname: Lai
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Tianqing
authors.initials: T
authors.lastname: Zheng
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Shen
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics / Q000378:metabolism*; D050901:Nitrate Reductase / Q000235:genetics / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D009569:Nitric Oxide; D012965:Sodium Chloride; D010088:Oxidoreductases; C521947:NOA1 protein, Arabidopsis; D019001:Nitric Oxide Synthase; C585690:HY1 protein, Arabidopsis; D006419:Heme Oxygenase (Decyclizing); C518487:HY2 protein, Arabidopsis; D050901:Nitrate Reductase
keywords: Arabidopsis; NIA/NR; NOA1; haem oxygenase-1 (HY1); nitric oxide; salt tolerance.