Evolutionary Divergence of DREB Regulatory Networks in C4 Cereals: In Silico Analysis and Implications for Climate-Resilient Breeding

Global crop productivity is threatened by climate change, necessitating the development of stress-resilient varieties. Dehydration Responsive Element Binding (DREB) transcription factors are master regulators of abiotic stress responses, yet their application is often limited by yield trade-offs. In this study, we integrated a systematic review with comparative in silico and quantitative meta-analyses to resolve this bottleneck. Our phylogenomic profiling reveals that drought-resilient C4 crops ( Zea mays, Sorghum bicolor ) possess a distinct DREB2 regulatory lineage (100% bootstrap support) characterized by a threefold enrichment of ABA-Responsive Elements (ABRE) compared to sensitive C3 crops. Furthermore, our meta-analysis of 11 transgenic field trials demonstrates that while constitutive overexpression frequently incurs yield penalties (avg. -20% to -54%), stress-inducible strategies consistently deliver significant yield gains (up to +104%) without biomass reduction. This study proposes a ’regulatory priming’ model for optimizing DREB engineering to develop climate-smart crops.