title: Functional characterization of a glucosyltransferase gene, LcUFGT1, involved in the formation of cyanidin glucoside in the pericarp of Litchi chinensis.
abstract: Anthocyanins generate the red color in the pericarp of Litchi chinensis. UDP-glucose: flavonoid 3-O-glycosyltransferase (UFGT, EC. 2.4.1.91) stabilizes anthocyanidin by attaching sugar moieties to the anthocyanin aglycone. In this study, the function of an UFGT gene involved in the biosynthesis of anthocyanin was verified through heterologous expression and virus-induced gene silencing assays. A strong positive correlation between UFGT activity and anthocyanin accumulation capacity was observed in the pericarp of 15 cultivars. Four putative flavonoid 3-O-glycosyltransferase-like genes, designated as LcUFGT1 to LcUFGT4, were identified in the pericarp of litchi. Among the four UFGT gene members, only LcUFGT1 can use cyanidin as its substrate. The expression of LcUFGT1 was parallel with developmental anthocyanin accumulation, and the heterologously expressed protein of LcUFGT1 displayed catalytic activities in the formation of anthocyanin. The LcUFGT1 over-expression tobacco had darker petals and pigmented filaments and calyxes resulting from higher anthocyanin accumulations compared with non-transformed tobacco. In the pericarp with LcUFGT1 suppressed by virus-induced gene silencing, pigmentation was retarded, which was well correlated with the reduced-LcUFGT1 transcriptional activity. These results suggested that the glycosylation-related gene LcUFGT1 plays a critical role in red color formation in the pericarp of litchi.
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.|Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Jie-Qiong
authors.initials: JQ
authors.lastname: Zhang
authors.affiliation: Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Zi-Chen
authors.initials: ZC
authors.lastname: Wu
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.|Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Lai
authors.affiliation: Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Xu-Ming
authors.initials: XM
authors.lastname: Huang
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Qin
authors.affiliation: Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Hui-Cong
authors.initials: HC
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou, China.|Physiological Laboratory for South China Fruits, College of Horticulture, South China Agricultural University, Guangzhou, China.
authors.forename: Gui-Bing
authors.initials: GB
authors.lastname: Hu