Abstract:Flavonol synthase, catalysing dihydroflavonol to flavonol, play a key role in flavonoids metabolic pathway. In order to study the function of flavonol synthase in flavonoids metabolism of tartary buckwheat, Tartary buckwheat flavonol synthase gene FtFLS2 was cloned by homology-based cloning.and a prokaryotic expression vector pET47b-FtFLS2 was constructed The overexpressed protein was purified by cobalt chelating chromatography and served as antigen for polyclonal antibody preparation and for enzymatic activity assay. The results showed that the recombinant FtFLS2 protein was expressed in a soluble form in E.coli BL21 Star(DE3) and had the catalytic activity to convert dihydroquercetin to quercetin. Western blotting results indicated that FtFLS2 was mainly expressed in immature seeds of tartary buckwheat. These results laid the foundation for further revealing the relationships between FtFLS2 expression level and accumulation of flavonoids in Tartary Buckwheat.