Epigenomic studies in sorghum reveal differential enrichment of multiple histone marks at clade A PP2C genes in response to drought

Epigenetic regulation is essential for plant development and stress responses, as numerous stress-responsive genes are modulated epigenetically. However, most research has focused on individual histone marks. This study expands on previous work by examining the genome-wide profiles of seven histone marks (H3K9ac, H3K27ac, H3K4me3, H3K36me3, H3K27me3, H2A.Z, and H3K4me2) in sorghum leaves and roots under PEG-induced drought stress. Results revealed that five histone marks (excluding H3K36me3 and H3K27me3) were significantly associated with drought-responsive gene expression. The differential enrichment of these marks may enhance the induction of drought-responsive genes. Specifically, a subset of genes showed multiple histone marks' differential enrichment, with most clade A PP2C genes exhibiting enrichment for four marks after PEG treatment. This suggests a critical role for robust PP2C gene induction in sorghum’s drought response. Additionally, promoter cis -element analysis identified ERF family transcription factors as potential mediators of histone mark enrichment under drought conditions, providing new insights into the interaction between epigenetic modifications and transcriptional regulation in plant stress responses. • H3K9ac, H3K27ac, H3K4me3, H2A.Z, and H3K4me2 are involved in the regulation of drought-induced gene expression in sorghum. • Clade A PP2C genes show differential enrichment of multiple histone marks induced by drought. • ERF family transcription factors have the potential to mediate changes in histone marks in response to drought stress.