title: Proteomics reveals the overlapping roles of hydrogen peroxide and nitric oxide in the acclimation of citrus plants to salinity.
abstract: Hydrogen peroxide (H(2)O(2)) and nitric oxide (*NO) are key reactive species in signal transduction pathways leading to activation of plant defense against biotic or abiotic stress. Here, we investigated the effect of pre-treating citrus plants (Citrus aurantium L.) with either of these two molecules on plant acclimation to salinity and show that both pre-treatments strongly reduced the detrimental phenotypical and physiological effects accompanying this stress. A proteomic analysis disclosed 85 leaf proteins that underwent significant quantitative variations in plants directly exposed to salt stress. A large part of these changes was not observed with salt-stressed plants pre-treated with either H(2)O(2) or sodium nitroprusside (SNP; a *NO-releasing chemical). We also identified several proteins undergoing changes either in their oxidation (carbonylation; 40 proteins) and/or S-nitrosylation (49 proteins) status in response to salinity stress. Both H(2)O(2) and SNP pre-treatments before salinity stress alleviated salinity-induced protein carbonylation and shifted the accumulation levels of leaf S-nitrosylated proteins to those of unstressed control plants. Altogether, the results indicate an overlap between H(2)O(2)- and *NO-signaling pathways in acclimation to salinity and suggest that the oxidation and S-nitrosylation patterns of leaf proteins are specific molecular signatures of citrus plant vigour under stressful conditions.
authors.affiliation: Laboratory of Agricultural Chemistry, School of Agriculture, Aristotle University of Thessaloniki, University Campus, 54124 Thessaloniki, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Tanou
authors.forename: Claudette
authors.initials: C
authors.lastname: Job
authors.forename: Loïc
authors.initials: L
authors.lastname: Rajjou
authors.forename: Erwann
authors.initials: E
authors.lastname: Arc
authors.forename: Maya
authors.initials: M
authors.lastname: Belghazi
authors.forename: Grigorios
authors.initials: G
authors.lastname: Diamantidis
authors.forename: Athannasios
authors.initials: A
authors.lastname: Molassiotis
authors.forename: Dominique
authors.initials: D
authors.lastname: Job
mesh_terms: D000064:Acclimatization / Q000187:drug effects* / Q000502:physiology; D002957:Citrus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome; D040901:Proteomics; D015398:Signal Transduction / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D020543:Proteome; D009599:Nitroprusside; D009569:Nitric Oxide; D012965:Sodium Chloride; D006861:Hydrogen Peroxide