Genome-wide characterization and expression analysis of the YUCCA genes in castor ( Ricinus Communis L.)

Auxin plays an essential role in all stages of plant growth and development. Castor (Ricinus communis L.) is an important oil and bioenergy crop with substantial potential. However, few studies have been conducted on auxin in castor, and the endogenous auxin synthesis process in this plant remains unknown. In this study, the amino acid sequences of the Arabidopsis thaliana YUCCA (AtYUC) proteins were used as query sequences to perform BLAST searches against in the castor genome database. A total of nine YUCCA-like genes (named RcYUCs) were identified in the castor genome. Gene structure, conserved domain, and phylogenetic analyses were then performed on these RcYUCs. The expression pattern of RcYUCs was determined by real-time PCR. The average length and relative molecular weight of the RcYUC proteins were 402 amino acids and 44.99 kDa, respectively, and all were amphoteric proteins. Furthermore, the RcYUC proteins were found to contain conserved flavin monooxygenase (FMO) motifs. High expression of the RcYUC4, 6, and 10a genes was observed in seeds, suggesting an important role in seed development. These findings provide a basis for further investigation into RcYUCs gene function.