Overexpression of Grapevine VvWRKY57 Enhances Salt Tolerance in Arabidopsis thaliana

Soil salinization is one of the major abiotic stresses limiting agricultural production. As an economically important fruit tree worldwide, grapevine generally exhibits weak salt tolerance. Therefore, identifying key stress-tolerance genes is of great significance for improving stress resistance in grapevines. In this study, the transcription factor gene VvWRKY57, which is induced by salt stress, was cloned from the grape cultivar Vitis vinifera ‘Shine Muscat’. Its function under salt stress was systematically evaluated via heterologous overexpression in Arabidopsis thaliana. The full-length CDS of the VvWRKY57 gene is 915 bp, encoding a protein of 305 amino acids. The protein contains a typical WRKY conserved domain, belongs to group II of the WRKY family, and is localized in the nucleus and cytoplasm. Expression pattern analysis showed that VvWRKY57 was expressed in roots, stems, and leaves of grapevine. Based on this expression profile, transgenic Arabidopsis thaliana plants overexpressing VvWRKY57 were generated to further investigate its role in salt tolerance. Subsequent salt tolerance assays revealed that, compared with wild-type plants, the overexpression lines exhibited stronger resistance phenotypes under salt stress. This study demonstrates for the first time that grape-derived VvWRKY57 functions in enhancing salt tolerance in model plants, providing a novel genetic resource and theoretical basis for crop salt-tolerance molecular breeding using this gene.