Current advances in structure, evolution, and abiotic stress regulatory mechanisms of TaWRKY transcription factors.

Wheat (Triticum aestivum; Ta) being a major staple crop for 40% of the world’s population, is key to food security. Climate extremes especially temperature, drought and salinity, urge scientists to develop high yielding and stress tolerant wheat varieties to fulfil growing population’s needs. WRKY transcription factors (WRKY TFs) are regulatory proteins belonging to a superfamily that regulates plant responses to environmental signals. This review highlights current advances in the structure, classification, and regulatory mechanisms of TaWRKY TFs and integrates evidence from transcriptomic and functional studies to elucidate their molecular roles in drought, salinity, and temperature tolerance. The TaWRKY TFs are characterized by the conserved WRKYGQK motif and zinc-finger domain that allow them to bind to W-box cis-elements of stress responsive genes. Specific TaWRKY TFs have been identified to play crucial role in abiotic stress tolerance, for instance, TaWRKY2 increases drought resistance by modulating ABA dependent genes, TaWRKY44 enhances salt tolerance by antioxidant defense, and TaWRKY10 increases thermotolerance by regulating ROS detoxification. Upregulation of such TaWRKYs in transgenic plants improved physiological traits like relative water content, osmolyte accumulation, and chlorophyll stability. This study identified key research gaps including limited insights into signal crosstalk and post translational modifications, and provides future directions for exploiting TaWRKYs in genetic engineering for multi-stress resilient wheat.