Integrated transcriptomic and metabolomic analyses reveal that flavonoid metabolic pathways are associated with petal discoloration in Aquilegia viridiflora s.l

The primary ornamental feature of Aquilegia plants is their coloration, which corresponds to the content of flavonoids in the petals. To investigate intrinsic mechanisms of these color changes, we performed metabolomic and transcriptomic analyses of differently colored A. viridiflora specimens. A total of 385 flavonoid metabolites were identified, showing significant variations of anthocyanin and flavonoid contents among different populations. Integrated transcriptomic analysis identified key differentially expressed genes, including C4H, HCT, CHS, CHI, F3H, FLS, DFR, LAR, and ANS as strong candidate regulators of flavonoid biosynthesis. Additionally, a stepwise regression analysis with environmental variables indicated that the color variation may be influenced by the average monthly diurnal temperature range. This study identifies key genes and metabolites involved in regulating petal color via flavonoid biosynthesis pathways. These findings provide a foundation for further elucidating the molecular mechanisms of color variation.