Integration of transcriptomic and chemical analysis reveals key regulatory mechanisms involved in color variation between red and white flowers of Camellia semiserrata
摘要
Camellia semiserrata is a woody ornamental plant, mainly known for its red flowers, with a variant that features white flowers called C. semiserrata form. albiflora. So far, its molecular mechanism remains unclear. Hereby, we performed a systematic study, subjecting petals of two Camellia species to transcriptomic and chemical analysis to uncover the obvious color variation between red and white flowers in C. semiserrata. The chemical analysis results indicated that proanthocyanidins were detected in both studied Camellia species. While a total of six anthocyanins were detected in C. semiserrata, no anthocyanins were detected in C. semiserrata form. albiflora. Cyanidin glucoside (cyanidin-3-O-glucoside) was the main substance contributing to petal color in C. semiserrata. Eleven structural genes annotated in the anthocyanin biosynthesis pathways exhibited strong downregulation in white flowers compared to red flowers. Significant downregulation of anthocyanin biosynthesis and transport genes was predicted to hinder anthocyanin accumulation, leading to white coloration. Through bioinformatics analysis of the CsUFGT (TRINITY_DN3641_c0_g1) identified in C. semiserrata, it is speculated that it may catalyze the final step of anthocyanin glycoside biosynthesis. This study elucidated the molecular characteristics of color variation in C. semiserrata, which can aid future breeding programs.