title: Involvement of three putative glucosyltransferases from the UGT72 family in flavonol glucoside/rhamnoside biosynthesis in Lotus japonicus seeds.
abstract: Flavonols are one of the largest groups of flavonoids that confer benefits for the health of plants and animals. Flavonol glycosides are the predominant flavonoids present in the model legume Lotus japonicus. The molecular mechanisms underlying the biosynthesis of flavonol glycosides as yet remain unknown in L. japonicus. In the present study, we identified a total of 188 UDP-glycosyltransferases (UGTs) in L. japonicus by genome-wide searching. Notably, 12 UGTs from the UGT72 family were distributed widely among L. japonicus chromosomes, expressed in all tissues, and showed different docking scores in an in silico bioinformatics docking analysis. Further enzymatic assays showed that five recombinant UGTs (UGT72AD1, UGT72AF1, UGT72AH1, UGT72V3, and UGT72Z2) exhibit activity toward flavonol, flavone, and isoflavone aglycones. In particular, UGT72AD1, UGT72AH1, and UGT72Z2 are flavonol-specific UGTs with different kinetic properties. In addition, the overexpression of UGT72AD1 and UGT72Z2 led to increased accumulation of flavonol rhamnosides in L. japonicus and Arabidopsis thaliana. Moreover, the increase of kaempferol 3-O-rhamnoside-7-O-rhamnoside in transgenic A. thaliana inhibited root growth as compared with the wild-type control. These results highlight the significance of the UGT72 family in flavonol glycosylation and the role of flavonol rhamnosides in plant growth.
authors.affiliation: Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Qinggang
authors.initials: Q
authors.lastname: Yin
authors.affiliation: Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Guoan
authors.initials: G
authors.lastname: Shen
authors.affiliation: Department of Biophysics, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: Zhenzhan
authors.initials: Z
authors.lastname: Chang
authors.affiliation: Samuel Roberts Noble Foundation, Ardmore, OK, USA.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Hongwen
authors.initials: H
authors.lastname: Gao
authors.affiliation: Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Pang
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D044948:Flavonols / Q000096:biosynthesis; D005960:Glucosides / Q000096:biosynthesis; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D000070116:Lotus / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics
chemical_list: D044948:Flavonols; D005960:Glucosides; D010940:Plant Proteins; D016695:Glycosyltransferases; D005964:Glucosyltransferases
keywords: Enzymatic activity; flavonols; Lotus japonicus; seed; UDP-glycosltransferase; UGT72 family