Abstract:

TCP protein is the plant specific transcription factors, which plays an important role in the aspects of plant growth and development, signal transduction and biochemical stimulation response. In this research, we systematically screened the family members of TCP gene of Carica papaya and analyzed their phylogenetic relationship, conserved motifs, conserved domains, gene structure, protein tertiary structure and expression pattern in fruit maturation by using the bioinformatics methods. The results showed that 22 TCP genes existed in the Carica papaya TCP gene family. TCP gene family could be divided into two classes: Class Ⅰ and Class Ⅱ, and Class Ⅱ could be further classified into two subclasses (CYC/TB1 and CIN). Within the same subgroup, TCP proteins had similar conserved motifs and conserved domains, and there were large differences between different subgroups, indicating that different types of TCP proteins might have unique physiological functions. The 22 family members all had bHLH (basic-helix-loop-helix) conserved region and their genetic structure consisted of 1-7 exon and 1-6 introns; Gene expression in Class Ⅱ subgroup decreased significantly with fruit ripening, so it was assumed that Class Ⅱ subgroup had no effect on fruit ripening or inhibited fruit ripening. The above results would be helpful to reveal the function of TCP gene family members in Carica papaya.

Key words: Carica papaya, TCP transcription factor, bioinformatics analysis, expression pattern