Flavonoid biosynthesis regulation for leaf coloring of Cyclocarya paliurus

Cyclocarya paliurus leaves contain abundant flavonoids with beneficial bioactivities and antioxidant activities. Red leaves of Cyclocarya paliurus have been considered to have higher flavonoids content, while the flavonoid derivatives accumulation pattern was still unclear. To uncover the flavonoids variation mechanism during red young leaf growing, transcriptome and metabolome analysis on Cyclocarya paliurus clone with red leaves was made. Leaves samples of young red leaf, half red leaf and old green leaf stage were researched. The result showed that young red leaf contained higher anthocyanin and quercetin contents, while lower kaempferol and catechins contents compared to old green leaf. And flavonoid biosynthesis-related unigenes (UDP-flavonoid glucosyl transferase) were identified for promoting anthocyanin accumulation in the flavonoid biosynthesis pathway. Besides, transcription factors were also found to influence the flavonoids variation pattern in the red leave of C.paliurus. These findings provide information about the relationship between flavonoids and leaf color, and will be useful for C. paliurus selection.