Genome-Wide Identification, Characterization and Expression Profiles of the CCD Gene Family in Potato

Carotenoids are a class of C40 isoprenoid-derived fat-soluble pigments that play vital roles in plant physiology and human health and serve as precursors for several biologically critical regulatory molecules. Carotenoid cleavage dioxygenases (CCDs) are key enzymes that catalyze the selective oxidative cleavage of carotenoids into apocarotenoids, thereby significantly influencing plant development and responses to abiotic stress. Although extensive research has been conducted on many model species, comprehensive studies on the StCCD gene family in potato remain limited. In this study, we conducted a genome-wide analysis to identify and characterize the CCD gene family in potato. Phylogenetic and structural analyses classified the 17 StCCD genes into six distinct subfamilies, which are distributed across five chromosomes of the genome. Analysis of cis-acting regulatory elements revealed that the promoters of most StCCD genes contain various elements associated with light responsiveness, stress signaling, and phytohormone regulation. Molecular docking analysis indicated that CCD proteins exhibit distinct substrate specificity in their binding to carotenoids and intermediate products. The expression profiling of StCCD genes uncovered pronounced specificity in their expression, which was evident across tissues, throughout tuber maturation, and following exposure to abiotic stresses and hormonal applications. This specificity strongly implicates these genes in the regulation of developmental processes and stress adaptation mechanisms. This study provides a comprehensive genomic and transcriptomic overview of the CCD gene family in potato, establishing a foundation for functional characterization of individual genes in the future.