Genome-wide identification and functional analyses of the TCP gene family in Carthamus tinctorius L.

TCP transcription factors play crucial roles in regulating plant growth, development, and the response to abiotic stress. However, members of the TCP family in Carthamus tinctorius L. have not been reported yet. To address this, we conducted a genome-wide analysis of the TCP gene family in C. tinctorius. By using bioinformatics tools and transcriptome data, we identified 22 CtTCP genes unevenly distributed across 7 chromosomes. Collinear relationships were found in 13 genes pairs, and 14 genes involved in whole-genome or segmental duplication events. Amino acid sequence alignment and phylogenetic analysis classified CtTCP into Class I (PCF) and Class II (CIN and CYC/TB1). The motifs and gene structures within each subgroup were similar, and each subgroup contained unique motifs. Additionally, CtTCP1,3,22 were confirmed to localize in the nucleus as predicted. On the basis of transcriptome data and phylogenetic analysis, CtTCP5 and CtTCP4 may play significant roles in the development of C. tinctorius leaves and flowers, respectively. Meanwhile, CtTCP4,11,12,15 might influence the formation of red petals in C. tinctorius. qRT‒PCR analysis showed that the expression of most CtTCP genes were upregulated after exposure to ABA, drought, salt and cold stresses. Specifically CtTCP1, 3, 5 were shown to play important roles in adverse stress. This study provides insights into the functions of CtTCP genes and their potential for improving stress tolerance and flower color in C. tinctorius. Future research should focus on functional validation and breeding applications.