Roles of sodium hydrosulfide and sodium nitroprusside as priming molecules during drought acclimation in citrus plants

Abstract

Emerging evidence suggests that the gaseous molecules hydrogen sulfide (H2S) and nitric oxide (NO) enhances plant acclimation to stress; however, the underlying mechanism remains unclear. In this work, we explored if pretreatment of citrus roots with NaHS (a H2S donor) or sodium nitroprusside (SNP, a NO donor) for 2 days (d) could elicit long-lasting priming effects to subsequent exposure to PEG-associated drought stress for 21 d following a 5 d acclimation period. Detailed physiological study documented that both pretreatments primed plants against drought stress. Analysis of the level of nitrite, NOx, S-nitrosoglutahione reductase, Tyr-nitration and S-nitrosylation along with the expression of genes involved in NO-generation suggested that the nitrosative status of leaves and roots was altered by NaHS and SNP. Using a proteomic approach we characterized S-nitrosylated proteins in citrus leaves exposed to chemical treatments, including well known and novel S-nitrosylated targets. Mass spectrometry analysis also enabled the identification of 42 differentially expressed proteins in PEG alone-treated plants. Several PEG-responsive proteins were down-regulated, especially photosynthetic proteins. Finally, the identification of specific proteins that were regulated by NaHS and SNP under PEG conditions provides novel insight into long-term drought priming in plants and in a fruit crop such as citrus in particular.

Activation of Secondary Metabolism in Citrus Plants Is Associated to Sensitivity to Combined Drought and High Temperatures

“…Data demonstrated that Carrizo is more tolerant than Cleopatra to heat applied individually or in combination with drought, concluding that higher transpiration and photosynthetic rates along with a stronger antioxidant defense is crucial in determining tolerance to a combination of drought and heat stress in citrus (Table S1; Zandalinas et al, 2016b). However, it has been previously shown that citrus respond to environmental stresses by modifying their metabolism (Tanou et al, 2014; Ziogas et al, 2015; Shiratake and Suzuki, 2016). Therefore, a metabolomics approach was followed to identify additional metabolic mechanisms underlying the superior tolerance of Carrizo to HS and WS+HS.…”

Protein Tyrosine Nitration during Development and Abiotic Stress Response in Plants

“…These results suggest that the roots of these plants may be more susceptible to nitration or that the nitration of these proteins could play a role in protection against nitro-oxidative stress. Recently, it has been also reported that NO-pretreatment could prime citrus plants against drought stress (Ziogas et al, 2015). Therefore, these results suggest that this NO-PTM could prepare the plant against a drought stress.…”

“…In higher plants, NO plays key roles in several physiological processes and in the response to several biotic and abiotic stress conditions (Beligni and Lamattina, 2000, 2001; Corpas et al, 2008; Chaki et al, 2009a, 2013; Lozano-Juste et al, 2011; Airaki et al, 2012; Begara-Morales et al, 2013; Signorelli et al, 2013; Ziogas et al, 2015; Feigl et al, 2016; Krasuska et al, 2016). …”

Different adaptation strategies of two citrus scion/rootstock combinations in response to drought stress

“…The genes APS1, SIR, SHM1 and OASB1 were repressed (-0.903, -1.317, -1.012 and -1.317 fold changes, respectively; Table 1, Fig 3) while the gene THA1 was overexpressed (1.425 fold change; Table 1, Fig 3). The sulfur assimilation seems to play an important role in drought and oxidative stress [75–78]. The interaction between hydrogen sulfide (H 2 S) and nitric oxide (NO) has been shown and was related to stomatal aperture/closure via ABA-dependent pathway [75].…”