Overexpression of TaWRKY46 enhances drought tolerance in transgenic wheat

Drought stress is a severe environmental factor that greatly restricts plant distribution and crop production. Transgenic breeding offers new opportunities for developing drought-resistant varieties. The WRKY transcription factors have been reported to be involved in various plant physiological and biochemical processes. In this study, we report the impact of TaWRKY46 on abiotic tolerance in wheat (Triticum aestivum L.). The transcription levels of the TaWRKY46 gene were differentially regulated by diverse abiotic stresses and hormone treatments, including PEG-induced stress (20% polyethylene glycol 6000), cold (4 °C), salt (100 mM NaCl), abscisic acid (100 μM ABA) and hydrogen peroxide (10 mM HO). The TaWRKY46-GFP fusion protein was localized to the nucleus of wheat protoplast. The N-terminal of TaWRKY46 showed transcriptional activation activity. Overexpression of TaWRKY46 in wheat resulted in enhanced drought stress tolerance. TaWRKY46-overexpressing plants exhibited increase survival rate, soluble sugar, proline and superoxide dismutase (SOD), as well as higher activities of catalase (CAT) and peroxidase (POD), but lower contents of malondialdehyde (MDA) and HO content. Taken together, our results indicate that TaWRKY46 functions as a positive factor under drought stress by regulating the osmotic balance and ROS scavenging.