ABSTRACT Drought stress severely limits global wheat productivity. Herein, the function of TaERF1‐A , encoded by a previously undescribed wheat ERF gene, in enhancing drought stress tolerance was analyzed. TaERF1‐A exhibited nuclear localisation and transcriptional activation activity in planta, although no transactivation was detected in yeast. Notably, TaERF1‐A was upregulated under drought and salt stress. TaERF1‐A overexpression (OE) in Arabidopsis enhanced drought stress resistance, resulting in increased transcription levels of stress‐ and antioxidant‐enzyme–related genes. BSMV‐ TaERF1 ‐ A –silenced wheat plants exhibited exacerbated wilting under drought, accompanied by elevated malondialdehyde levels, reduced proline accumulation, and decreased antioxidant enzyme activity levels. In contrast, TaERF1 ‐ A OE wheat lines exhibited enhanced drought tolerance, with opposite physiological trends. Notably, RNAi induced a weakened response in wheat compared to wild‐type wheat. Yeast one‐hybrid, electrophoretic mobility shift, dual‐luciferase, and qRT‐PCR assays demonstrated that TaWRKY33 directly binds the TaERF1‐A promoter, thereby activating its transcription. TaWRKY33 overexpression also enhanced drought tolerance in wheat. TaERF1‐A subsequently regulated TaP5CS2 expression, which stimulated proline biosynthesis, thereby contributing to improved drought resistance. This study elucidates the mechanism by which the TaWRKY33–TaERF1‐A–TaP5CS2 module positively regulates drought tolerance and highlights the candidate genes that can be explored for developing elite drought‐resistant wheat varieties.
Yu et al. (Fri,) studied this question.