Proteomics reveals the overlapping roles of hydrogen peroxide and nitric oxide in the acclimation of citrus plants to salinity

Abstract

SUMMARYHydrogen 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 pretreating 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.

Alterations of Endogenous Hormonal Levels in Plants under Drought and Salinity

“…Similar to NO role in antioxidant activity in response to drought, some studies support the same NO role during the salinity tolerance. In this regard, [99] showed that exogenous NO application induce antioxidant enzymes activity, promote the maintenance of the cellular redox homeostasis and mitigate the oxidative damage produced by salt stress. Moreover, there is some experimental evidence that pre-exposure to NO efficiently protect plants to salinity.…”

“…For example, drought-induced NO production has been reported in many plant species, including pea, wheat and tobacco [98]. Also, an increase of endogenous NO level via application of exogenous NO donor (sodium nitroprusside, SNP) has been shown to confer resistance to drought and salinity [99]. [100] reported in cucumber seedling subjected to water deficit (5 to 10 h at the stage of the third fully expanded leaf) a slight NO production in cells of root tips and in the surrounding elongation zone compared with 17 h of water deficit, which resulted in a high increase in NO production.…”

Rapid plant rehydration initiates permanent and adverse changes in the photosynthetic apparatus of triticale

“…It has been known since the 1970s that an increase in hydrogen peroxide content affects the activity of the Calvin cycle enzymes (Kaiser 1979). Tanou et al (2009) reported that plants exposed to H 2 O 2 activated specific proteome reprogramming to prevent accumulation of proteins, e.g., the key enzymes of the Calvin cycle (Rubisco activase, Rubisco large subunit, fructose 1,6-bisphosphate aldolase, phosphoglycerate kinase, glyceraldehyde-3-phosphate dehydrogenase, phosphoribulokinase, transketolase and carbonic anhydrase). Hence, it may be speculated that the impact of rapid rehydration after drought at the tillering stage on low photosynthesis during the reproductive phase is connected with H 2 O 2 -induced gene expression related to persistent limitation in CO 2 assimilation.…”

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling

“…H 2 O 2 plays a dual role in plants: at low concentrations, it serves as a signal molecule, playing a pivotal role in signal transduction network under various stress conditions (Tanou et al, 2009;Jiang et al, 2012;Lizárraga-Paulín et al, 2013); …”