Ectopic expression of CaWRKY1, a pepper transcription factor, enhances drought tolerance in transgenic potato plants

WRKY transcription factors play a major role in plant biotic and abiotic stress responses. In this study, WRKY transcription factor, CaWRKY1, whose expression was strongly induced by cold and abscisic acid treatment in pepper, was cloned into potato via Agrobacterium-mediated transformation of vector expressing CaWRKY1 under control of the CaMV35S promoter. The overexpression of CaWRKY1 in potato plants increased tolerance to drought stress without noticeably affecting other agricultural important factors, such as plant height, leaf size and tuber formation. In addition, CaWRKY1-overexpressing transgenic potato plants showed increased expression of abiotic stress-related genes, such as C-REPEAT BINDING FACTOR 3 (CBF3), ZINC FINGER PROTEIN ZAT10 (ZAT10), TREHALOSE-6-PHOSPHATE SYNTHASE (TPS) and LATE EMBRYOGENESIS ABUNDANT (LEA). These results suggest that CaWRKY1 can regulate drought stress tolerance in potato plants via the activation of putative stress-responsive genes.