title: Cloning, characterization, and activity analysis of a flavonol synthase gene FtFLS1 and its association with flavonoid content in tartary buckwheat.
abstract: Evidence from in vitro and in vivo studies indicates that rutin, the main flavonoid in tartary buckwheat ( Fagopyrum tataricum ), may have high value for medicine and health. This paper reports the finding of a flavonol synthase (FLS) gene, cloned and characterized from F. tataricum and designated FtFLS1, that is involved in rutin biosynthesis. The FtFLS1 gene was expressed in  Escherichia coli  BL21(DE3), and the recombinant soluble FtFLS1 protein had a relative molecular mass of 40 kDa. The purified recombinant protein showed, with dihydroquercetin as substrate, total and specific activities of 36.55 × 10(-3) IU and 18.94 × 10(-3) IU/mg, respectively, whereas the total and specific activities were 10.19 × 10(-3) IU and 5.28 × 10(-3) IU/mg, respectively, with dihydrokaempferol. RT-PCR revealed that during F. tataricum florescence there was an organ-specific expression pattern by the FtFLS1 gene, with similar trends in flavonoid content. These observations suggest that FtFLS1 in F. tataricum encodes a functional protein, which might play a key role in rutin biosynthesis.
authors.affiliation: College of Life Science,  Sichuan Agriculture University , Ya'an 625014, Sichuan, People's Republic of China.
authors.forename: Chenglei
authors.initials: C
authors.lastname: Li
authors.forename: Yuechen
authors.initials: Y
authors.lastname: Bai
authors.forename: Shuangjiang
authors.initials: S
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Xueyi
authors.initials: X
authors.lastname: Han
authors.forename: Haixia
authors.initials: H
authors.lastname: Zhao
authors.forename: Jirong
authors.initials: J
authors.lastname: Shao
authors.forename: Sang-Un
authors.initials: SU
authors.lastname: Park
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
mesh_terms: D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D019612:Fagopyrum / Q000737:chemistry* / Q000235:genetics*; D005419:Flavonoids / Q000032:analysis*; D015870:Gene Expression; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012431:Rutin / Q000096:biosynthesis
chemical_list: D005419:Flavonoids; D010940:Plant Proteins; D011994:Recombinant Proteins; D012431:Rutin; D010088:Oxidoreductases; C085313:flavonol synthase