Identification and Characterization of the RcTCP Gene Family and Its Expression in Response to Abiotic Stresses in Castor Bean

Abstract

Background The TCP (teosinte branched1/cincinnata/proliferating cell factor) family plays a prominent role in plant development and stress responses. However, TCP family genes have thus far not been identified in castor bean, and therefore an understanding of the expression and functional aspects of castor bean TCP genes is lacking. To identify the potential biological functions of castor bean (RcTCP) TCP members, the composition of RcTCP family members, their basic physicochemical properties, subcellular localizations, interacting proteins, miRNA target sites, and gene expression patterns under stress were assessed. Results Twenty RcTCP genes were found to be unevenly distributed on the nine chromosomes of castor bean, and all of these genes possessed a TCP domain. Phylogenetic analysis indicated that the RcTCP genes were closely related to Arabidopsis AtTCP genes. Subcellular localization experiments indicated that RcTC01/02/03/10/16/18 were all localized in the nucleus. Protein interaction analysis showed that the RcTCP03/06/11 proteins had the highest number of interacting proteins. Furthermore, the promoter region of the RcTCP genes was found to contain numerous stress-responsive elements and hormone-induced elements, indicating a potential link between RcTCP genes and their function in response to stress. The 20 RcTCP genes exhibited obvious tissue-specific expression patterns, and the expression of these genes was induced by abiotic stress (including low temperature, abscisic acid, drought, and high salt). The RcTCP01/03/04/08/09/10/14/15/18/19 genes may be excellent stress-response genes. Conclusion We discovered that RcTCP genes play a crucial role in various activities, including growth and development, the stress response, and transcription. This study offers an initial documentation of the potential significance of RcTCP genes in castor bean.