Characterization of histone acetyltransferase and histone deacetylase genes under abiotic and hormone stresses in soybean.

INTRODUCTION: Histone acetyltransferases (HATs) and histone deacetylases (HDACs) dynamically regulate histone acetylation and are involved in the process of plant growth and development and stress responses. METHODS: In this study, we identified 12 GmHATs and 28 GmHDACs in the soybean genome and systematically analyzed their phylogenetic relationships, structural features, expression profiles, and stress-induced acetylation dynamics using bioinformatics analysis, RT-qPCR, and western blotting. RESULTS: Cis-element analysis indicates that they may participate in hormone and stress signaling pathways, and transcriptome analysis revealed tissue-specific expression patterns. RT-qPCR results indicated that GmHATs and GmHDACs exhibited varying degrees of induced expression under salt and drought stress, particularly the GmHDA16 and GmHDT2. Notably, under salt stress, GmHDT2 expression increased 61-fold. Western blotting further demonstrated that salt and drought treatments significantly reduced H3K18ac and H4K8ac levels. Additionally, these genes exhibit distinct responses to various plant hormones. DISCUSSION: The reduction in acetylation was negatively correlated with the upregulation of HD2 subfamily genes, suggesting that specific HDACs mediate stress responses through histone deacetylation. This study provides new insights into the epigenetic regulation of abiotic stress in soybean, offering valuable genetic resources for future stress-resistant breeding programs.