Integrative transcriptional regulatory networks governing cereal root responses to heavy metals and drought

Cereal root systems perceive the onset of drought and heavy metal toxicity, which rapidly triggers signal transduction and extensive transcriptional reprogramming that underpins plant stress tolerance. This review discusses the transcriptional basis of root responses to abiotic stresses, emphasizing key regulatory genes and networks that orchestrate hormone signaling, redox dynamics, ion homeostasis, and structural modifications. Key transcription factor families-NAC, WRKY, bZIP, DREB, ARF, and MYB-serve as the nexus between the early perception and adaptive outputs such as controlled root growth, suberization, aerenchyma formation, and metal sequestration. Integrative transcriptomic, proteomic, metabolomic, and chromatin data in rice, wheat, maize, and millets highlight cell-type- and zone-specific regulatory programs, with single-cell and spatial omics uncovering modules obscured in bulk datasets. We discuss how CRISPR/Cas editing, cis-element engineering, and root-specific promoters refine core regulators, and how quantitative trait loci (QTL)/genome-wide association study (GWAS) advance breeding for drought and metal tolerance. Emerging concepts encompass multi-stress omics, high-throughput root phenomics, and artificial intelligence-driven network modeling, and collectively enable targeting of core transcriptional regulatory nodes. Overall, emerging knowledge supports targeted engineering of transcriptional regulators to develop resilient cereal root systems, contributing to sustainable yields and improved stress tolerance in real-world agroecosystems.