Abstract
Tartary buckwheat shows health benefits with its high antioxidant activity and abundant flavonoid content. However, glycosylated flavonoid accumulation patterns and their molecular basis remain unidentified in Tartary buckwheat. Here, our metabolomics analysis revealed that F3 & PRIME;H branching was the major flavonoid metabolic flux in Tartary buckwheat. Interestingly, metabolome results also showed that the most abundant flavonoids were mainly in the glycosylated form, including flavonoid glycosides and flavonoid diglycosides in Tartary buckwheat. However, the flavonoid glycosides glycosyltransferase (GGT) gene catalyzing the second glycosylation step of flavonoid diglycoside has not been discovered yet in Tartary buckwheat. Thus, we explored GGT genes in the transcriptome-metabolome correlation network and confirmed that FtUGT79A15 showed the rhamnosyltransferase activity to catalyze quercetin 3-O-glucoside to rutin in vitro and in planta. Overall, FtUGT79A15 was identified to involve in the flavonoid diglycoside biosynthesis pathway in Tartary buckwheat.
NSTL
Elsevier