Genome-wide identification of gene family and functional analysis of under cold stress in cotton.

Cotton fiber, the mainstay of the world's textile industry, is formed by the differentiation of epidermal cells on the outer peridium of the ovule. The gene family is involved in the regulation of epidermal hair development as well as response to abiotic stress. However, the function of genes in cotton has not been systematically studied yet. Here, we identified 131 and 130 genes in TM-1 () and Hai7124 (), respectively. Phylogenetic, gene structure, expression pattern and -element of promoter analysis were performed and compared. Single gene association analysis indicated that more genes related to fiber quality traits were found in , whereas more genes associated with yield traits were found in . One gene, (GH_D04G0930), was induced by treatment at 4°C for 12 and 24 h in and silencing of the gene by VIGS technology in TM-1 can significantly improve the resistance of cotton seedlings to low temperature stress. In sum, our study conducted a genome-wide identification and comparative analysis of family genes in and and demonstrated a group of genes significantly associated with fiber quality and excavated cold stress responsive gene, such as , providing a theoretical basis for further improving cotton agronomic traits.