Identification and Characterization of Histone Modification Gene Families and Their Expression Patterns During Pod and Seed Development in Peanut

Histone methylation and acetylation play potential roles in plant growth and development through various histone modification (HM) genes. However, studies of HM genes are still limited in peanut (<i>Arachis hypogaea</i> L.), a globally important oilseed crop. Here, comprehensive identification and investigation of HM genes were performed using the whole genome of peanut, and a total of 207 <i>AhHMs</i> encoding 108 histone methyltransferases, 51 histone demethylases, 16 histone acetylases, and 32 histone deacetylases were identified. Detailed analysis of these <i>AhHMs</i>, including chromosome locations, gene structures, protein motifs, and protein-protein interactions, was performed. Tandem, segmental, transposed, dispersed, and whole-genome duplications were involved in the evolution and expansion of the HM gene families in peanut. Ka/Ks analysis indicated that the <i>AhHMs</i> underwent purifying selection. The expression profiles of the 207 <i>AhHMs</i> were investigated during the pod and seed development stages on the basis of the transcriptome sequencing results. Quantitative real-time PCR confirmed that eight <i>AhHMs</i> were differentially expressed during pod and seed development. These results provide data support for further studying the epigenetic mechanism of peanut histones, deepen the understanding of seed development, and provide a new direction for the cultivation of more high-yield and high-quality peanut varieties.