Genome-wide identification and functional analysis of class III peroxidases in .

() genes play essential roles in various processes, such as auxin catabolism, removal of HO, crosslinking cell wall components, and response to biotic and abiotic stresses. In this study, we identified 166, 78 and 89 genes from , and , respectively. These genes were classified into seven subfamilies based on phylogenetic tree analysis and the classification of genes in . Segmental duplication and purifying selection were the major factors driving the evolution of . GO and KEGG enrichment analysis revealed that genes were mainly associated with responding to oxidative stresses, peroxidase activities and phenylpropanoid biosynthesis pathways. Transcriptome data analysis showed that genes expression were significantly different in microspore development between the sterility line-JinA and the maintainer line MB177. We confirmed the up-regulation of and down-regulation of in the sterile line compared to its maintainer line using qRT-PCR, suggesting their roles in pollen fertility. In addition, silencing in cotton showed a significant decrease of the reactive oxygen species (ROS) levels of microsporocyte stage anthers compared to control. Overexpressing in significantly increased the ROS levels of anthers compared to wild type. In conclusion, we identified as a determinant of ROS levels in anther. This work sets a foundation for studies in pollen development.