title: Nitric oxide and S-nitrosoglutathione function additively during plant immunity.
abstract: Nitric oxide (NO) is emerging as a key regulator of diverse plant cellular processes. A major route for the transfer of NO bioactivity is S-nitrosylation, the addition of an NO moiety to a protein cysteine thiol forming an S-nitrosothiol (SNO). Total cellular levels of protein S-nitrosylation are controlled predominantly by S-nitrosoglutathione reductase 1 (GSNOR1) which turns over the natural NO donor, S-nitrosoglutathione (GSNO). In the absence of GSNOR1 function, GSNO accumulates, leading to dysregulation of total cellular S-nitrosylation. Here we show that endogenous NO accumulation in Arabidopsis, resulting from loss-of-function mutations in NO Overexpression 1 (NOX1), led to disabled Resistance (R) gene-mediated protection, basal resistance and defence against nonadapted pathogens. In nox1 plants both salicylic acid (SA) synthesis and signalling were suppressed, reducing SA-dependent defence gene expression. Significantly, expression of a GSNOR1 transgene complemented the SNO-dependent phenotypes of paraquat resistant 2-1 (par2-1) plants but not the NO-related characters of the nox1-1 line. Furthermore, atgsnor1-3 nox1-1 double mutants supported greater bacterial titres than either of the corresponding single mutants. Our findings imply that GSNO and NO, two pivotal redox signalling molecules, exhibit additive functions and, by extension, may have distinct or overlapping molecular targets during both immunity and development.
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.|School of Applied Biosciences, College of Agriculture and Life Sciences, KyungPook National University, 80 Daehak-ro, Buk-gu, Daegu, 7201-701, Korea.
authors.forename: Byung-Wook
authors.initials: BW
authors.lastname: Yun
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Skelly
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.
authors.forename: Minghui
authors.initials: M
authors.lastname: Yin
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.
authors.forename: Manda
authors.initials: M
authors.lastname: Yu
authors.affiliation: School of Applied Biosciences, College of Agriculture and Life Sciences, KyungPook National University, 80 Daehak-ro, Buk-gu, Daegu, 7201-701, Korea.
authors.forename: Bong-Gyu
authors.initials: BG
authors.lastname: Mun
authors.affiliation: School of Applied Biosciences, College of Agriculture and Life Sciences, KyungPook National University, 80 Daehak-ro, Buk-gu, Daegu, 7201-701, Korea.
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Lee
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.|School of Applied Biosciences, College of Agriculture and Life Sciences, KyungPook National University, 80 Daehak-ro, Buk-gu, Daegu, 7201-701, Korea.|Department of Agriculture, Abdul Wali Khan University, Mardan, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Adil
authors.initials: A
authors.lastname: Hussain
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Spoel
authors.affiliation: Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3BF, UK.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Loake
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D006706:Homeostasis; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D009569:Nitric Oxide / Q000378:metabolism*; D010641:Phenotype; D057865:Plant Immunity; D030821:Plants, Genetically Modified; D044224:Pseudomonas syringae / Q000502:physiology; D026422:S-Nitrosoglutathione / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione
keywords: S-nitrosylation and S-nitrosothiols; hypersensitive response; nitric oxide (NO); plant disease resistance; plant immunity; post-translational modifications; redox signalling