Identification, classification, and transcriptional analysis of TCP gene family from Scutellaria baicalensis and SbTCP genes response under MeJA and SA treatments

TCP transcription factor is a plant-specific gene family which plays important roles in many developmental control pathways, regulating secondary metabolites and plant responses to abiotic and biotic stresses. Nevertheless, this gene family remains unknown in Scutellaria baicalensis. Here, by identifying and analysing all the TCP transcription factor family members based on the transcriptome of S. baicalensis, a total of 19 SbTCP genes were obtained following gene classification, the phylogenetic relationship, conserved domain structure, functional differentiation, and an expression activity analysis. Phylogenetic analysis grouped the SbTCP genes into two subfamilies; we also found that SbTCP with the same motif structure clustered together in the evolutionary tree, and these results suggest that SbTCP proteins with the same gene structure have similar functions. Gene Ontology (GO) categorised the SbTCP genes into 17 functional subcategories, suggesting that they have diversified in functionality, even though their putative proteins share a number of conserved motifs. After the MeJA and SA treatments, the expression of SbTCP candidate genes containing MeJA and SA promoter elements was significantly higher or lower compared with the control, indicating that these candidate SbTCP genes could respond to different concentrations of MeJA and SA treatments. These comprehensive data provide a reference for elucidating the functions of TCP transcription factor family in the growth, development, and MeJA and SA stress response of S. baicalensis, this study can create a new avenue for understanding the role of TCP gene family in S. baicalensis.