PgWRKY44, a pearl millet WRKY transcription factor-Calmodulin module, enhances salt and drought stress resilience in transgenic plants

WRKY transcription factors (TFs) regulate signal transduction pathways during stress response and can also modulate the activity of downstream genes through binding to their cognate W -box elements [(T) TGAC(C/T)]. Previous studies have identified and in-silico characterized WRKY family members in millets. However, their functional elucidation and molecular mechanism in millets remain vastly unexplored. In this study, a pearl millet WRKY TF (PgWRKY44) belonging to Group IId was characterized, and its ectopic expression in Arabidopsis was found to be positively regulating abiotic stress tolerance in transgenic plants through ABA -mediated signalling. Also, reduced accumulation of reactive oxygen species (ROS) and up -regulation of stress -related genes confirmed improved defense systems of transgenic plants upon abiotic stress treatments. Functional network analysis and expression data indicated towards co -regulation of multiprotein bridging factor (MBF1C), HSFs, and calmodulin (CAM) members with PgWRKY44 in response to osmotic stress. Yeast one -hybrid also confirmed W -boxdependent binding of PgWRKY44. These findings enriched our understanding of the PgWRKY44 functions in pearl millet and exhibited its potential application in developing climate -resilient crop plants.