Overexpression of AtWRKY30 Transcription Factor Enhances Heat and Drought Stress Tolerance in Wheat (Triticum aestivum L.)

Drought and heat factors have negative impacts on wheat yield and growth worldwide. Improving wheat tolerance to heat and drought stress is of the utmost importance to maintain crop yield. WRKY transcription factors help improve plant resistance to environmental factors. In this investigation, Arabidopsis WRKY30 (AtWRKY30) transcription factor was cloned and expressed in wheat. Plants growth, biomass, gas-exchange attributes, chlorophyll content, relative water content, prolines content, soluble proteins content, soluble sugars content, and antioxidant enzymes activities (catalase (CAT), superoxide dismutase (SOD), peroxidase (POX), and ascorbate peroxidase (APX)) of the AtWRKY30-overexpressing wheat plants were higher than those of the wild type. However, levels of electrolyte leakage, malondialdehyde, and hydrogen peroxide of the AtWRKY30-overexpressing wheat plants were significantly less than those of the wild-type. Additionally, the expression level of antioxidant enzyme-encoding genes and stress-responsive genes (ERF5a, DREB1, DREB3, WRKY19, TIP2, and AQP7) were significantly induced in the transgenic wheat plants in comparison with the wild type. In conclusion, the results demonstrated that AtWRKY30 overexpression promotes heat and drought tolerance in wheat by inducing gas-exchange attributes, antioxidant machinery, osmolytes biosynthesis, and stress-related gene expression. AtWRKY30 could serve as a potential candidate gene for improving stress tolerance in wheat.