Salinity Effects on Guard Cell Proteome in Chenopodium quinoa

Epidermal fragments enriched in guard cells (GCs) were isolated from the halophyte quinoa (Chenopodium Wild.) species, and response at proteome level was studied after salinity treatment of 300 mM NaCl for 3 weeks. In total, 2147 proteins identified, which 36% differentially expressed to stress GCs. Up downregulated included signaling molecules, enzyme modulators, transcription factors oxidoreductases. The most abundant induced by salt desiccation-responsive protein 29B (50-fold), osmotin-like OSML13 (13-fold), polycystin-1, lipoxygenase, alpha-toxin, triacylglycerol lipase (PLAT) domain-containing 3-like (eight-fold), dehydrin early responsive dehydration (ERD14) (eight-fold). Ten related gene ontology term “response ABA” upregulated GC; this aspartic protease, phospholipase D plastid-lipid-associated protein. Additionally, seven sucrose–starch pathway GC stress, accumulation tryptophan synthase L-methionine (enzymes involved amino acid biosynthesis) observed. Exogenous application sucrose tryptophan, resulted reduction stomatal aperture conductance, could be advantageous plants under stress. Eight proteinase highly GCs quinoa, exogenous pepstatin A (an inhibitor proteinase) accompanied higher oxidative extremely low suggesting a possible role mitigating saline conditions.