Identification, Characterization, and Expression Patterns of TCP Genes and microRNA319 in Cotton

The TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTORS (TCP) gene family is a group of plant-specific transcription factors that have versatile functions in developmental processes and stress responses. In this study, a total of 73 TCP genes in upland cotton were identified and characterizated. Phylogenetic analysis classified them into three subgroups: 50 belonged to PCF, 16 to CIN, and 7 to CYC/TB1. GhTCP genes are randomly distributed in 22 of the 26 chromosomes in cotton. Expression patterns of GhTCPs were analyzed in 10 tissues, including different developmental stages of ovule and fiber, as well as under heat, salt, and drought stresses. Transcriptome analysis showed that 44 GhTCP genes exhibited varied transcript accumulation patterns in the tested tissues and 41 GhTCP genes were differentially expressed in response to heat, salt, and drought stresses. Furthermore, three GhTCP genes of the CIN clade were found to contain miR319-binding sites. An anti-correlation expression of GhTCP21 and GhTCP54 was analyzed with miR319 under salt and drought stress. Our results lay the foundation for understanding the complex mechanisms of GhTCP-mediated developmental processes and abiotic stress-signaling transduction pathways in cotton.