Genome-Wide Identification and Expression Analysis of BES1 Family in Catharanthus roseus

BES1 family genes function as the key regulator in BR signaling in various plant growth and development processes. As an intensively studied resource of vinblastine, a medicinal substance with anticancer properties, C. roseus is poorly understood in terms of the BES1 family and requires a comprehensive genomic and expressional analysis. In this study, seven CrBES1 family members were identified and classified into five groups based on the conserved motif, Pfam domain, gene structure, and phylogenetic analysis. Synteny of periwinkle and six other common species (tomato, Arabidopsis, pepper, rice, soybean, maize, and potato) were further analyzed to provide an insight into evolutionary relationships. Meanwhile, most cis-elements related to hormone, stress, and plant development were observed in the promoters of CrBES1 family genes. Subcellular localization showed five members located both in the nucleus and cytoplasm, implying the presence of dephosphorylated and phosphorylated form of these proteins, while another two members were located in the chloroplast. Furthermore, CrBES1-1, CrBES1-4, and CrBES1-7 principally expressed in flower, suggesting that they potentially function in flower development. Other members were observed to express in all organs. Moreover, CrBES1 genes exhibited variational expression in response to eight principal plant hormones. Notably, the expression level of CrBES1 genes presented a dominant downregulation in response to stress. This study reveals the genomic characterization of CrBES1 family through systematical analysis, as well as the functional features and expression patterns of their proteins, which lay a foundation for the functional research of CrBES1 family and flower development.