Genome-Wide Analysis of the Histone Modification Gene (HM) Family and Expression Investigation during Anther Development in Rice (Oryza sativa L.)

Histone modification plays a crucial role in chromatin remodeling and regulating gene expression, and participates in various biological processes, including plant development and responses to stress. Several gene families related to histone modification have been reported in various plant species. However, the identification of members and their functions in the rice (<i>Oryza sativa</i> L.) <i>histone modification</i> gene family (<i>OsHM</i>) at the whole-genome level remains unclear. In this study, a total of 130 <i>OsHMs</i> were identified through a genome-wide analysis. The <i>OsHM</i> gene family can be classified into 11 subfamilies based on a phylogenetic analysis. An analysis of the genes structures and conserved motifs indicates that members of each subfamily share specific conserved protein structures, suggesting their potential conserved functions. Molecular evolutionary analysis reveals that a significant number of <i>OsHMs</i> proteins originated from gene duplication events, particularly segmental duplications. Additionally, transcriptome analysis demonstrates that <i>OsHMs</i> are widely expressed in various tissues of rice and are responsive to multiple abiotic stresses. Fourteen <i>OsHMs</i> exhibit high expression in rice anthers and peaked at different pollen developmental stages. RT-qPCR results further elucidate the expression patterns of these 14 <i>OsHMs</i> during different developmental stages of anthers, highlighting their high expression during the meiosis and tetrad stages, as well as in the late stage of pollen development. Remarkably, <i>OsSDG713</i> and <i>OsSDG727</i> were further identified to be nucleus-localized. This study provides a fundamental framework for further exploring the gene functions of <i>HMs</i> in plants, particularly for researching their functions and potential applications in rice anthers' development and male sterility.