Genome-Wide Identification and Expression Pattern Analysis of the TCP Gene Family in Radish (Raphanus sativus L.)

TCP transcription factors are a unique transcription family in higher plants, and play important roles in plant development, responses to environmental stresses and phytohormones. Radish is an important crop and widely cultivated worldwide. However, genome-wide identification and expression analysis of TCP family in radish has not been reported yet. In this study, 32 RsTCP genes were identified from the whole genome. Phylogenetic analysis showed that the RsTCP family can be divided into two major groups and three subgroups, namely Class I (PCF), Class II (CIN), and Class II (CYC/TB1). Chromosome mapping showed that 32 genes were distributed on all nine chromosomes of radish. Transcriptome data indicated that the transcription of RsTCP genes differed between tissues and developmental stages. Multiple phytohormone-related cis-acting elements in the promoter region of RsTCPs and several post-translational modification sites in RsTCP protein sequences were identified. The real-time quantitative PCR (RT-qPCR) analysis indicated that several RsTCP genes changed significantly in response to the treatments, including low temperature, drought, salt, gibberellin (GA(3)), and abscisic acid. Among them, RsTCP16 showed significantly higher levels in leaves than in other radish tissues, and the transcription of RsTCP16 was significantly upregulated under the five treatments, especially during low temperature, salt shock, and GA(3) response, suggesting that RsTCP16 could be involved in the development of radish leaves and the response to stress. In summary, these results provided a basis for further exploring the molecular mechanism of RsTCP genes in radish.