The expression of wheat TaSTG gene can enhance salt tolerance in plants

Abstract

By exploring microarray data in a salt-tolerant wheat mutant, RH8706-49, we identified a novel stress-related gene, named TaSTG (Triticum aestivum salt tolerance gene), which can be induced by salt stress in wheat. Transgenic rice and Arabidopsis plants overexpressing TaSTG were generated and proved to be more salt-tolerant than the wild-type control. Seeds of transgenic Arabidopsis exhibited an elevated germination rate under salt stress. Compared with those of the wild type, the levels of chlorophyll, soluble sugars and proline in transgenic Arabidopsis were significantly higher, whereas the levels of Na+ and malondialdehyde were significantly lower. Moreover, the expression profile of seven salt tolerance-related genes, alcohol dehydrogenase class-P (ADH1), cold-regulated protein 15a (COR15A), inositol polyphosphate 1-phosphatase FIERY1 (FRY1), Gamma-glutamyl phosphate reductase (P5CS1), desiccation-responsive rd29 (RD29B), U6 snRNA-associated Sm-like protein (SAD1), salt overly sensitive 3 (SOS3), in transgenic Arabidopsis suggests their possible interaction with TaSTG. Compared with those of the wild type, the expression levels of six of these genes in transgenic plants were significantly increased, whereas the expression of SOS3 was decreased. We propose that TaSTG may act upstream of the up-regulated genes, possibly by regulating plant responses to osmotic stress through phospholipases and CDPK pathway, consequently enhancing plant salt tolerance via proline accumulation.