2024-03-29T05:36:35Z
https://soar-ir.repo.nii.ac.jp/oai
oai:soar-ir.repo.nii.ac.jp:00020550
2022-12-14T04:17:40Z
1309:1310
C‐Glycosyltransferases catalyzing the formation of di‐C‐glucosyl flavonoids in citrus plants
Ito, Takamitsu
Fujimoto, Shunsuke
Suito, Fumiaki
Shimosaka, Makoto
Taguchi, Goro
di-C-glucosylation
flavonoid C-glycosyltransferase
Fortunella crassifolia
24 Citrus unshiu
phloretin di-C-glucoside
vicenin-2
Citrus plants accumulate many kinds of flavonoids, including di‐C‐glucosyl flavonoids, which have attracted considerable attention due to their health benefits. However, the biosynthesis of di‐C‐glucosyl flavonoids has not been elucidated at the molecular level. Here, we identified the C‐glycosyltransferases (CGTs) FcCGT (UGT708G1) and CuCGT (UGT708G2) as the primary enzymes involved in the biosynthesis of di‐C‐glucosyl flavonoids in the citrus plants kumquat (Fortunella crassifolia) and satsuma mandarin (Citrus unshiu), respectively. The amino acid sequences of these CGTs were 98% identical, indicating that CGT genes are highly conserved in the citrus family. The recombinant enzymes FcCGT and CuCGT utilized 2‐hydroxyflavanones, dihydrochalcone, and their mono‐C‐glucosides as sugar acceptors and produced corresponding di‐C‐glucosides. The Km and kcat values of FcCGT toward phloretin were <0.5 μm and 12.0 sec−1, and those toward nothofagin (3ʹ‐C‐glucosylphloretin) were 14.4 μm and 5.3 sec−1, respectively; these values are comparable with those of other glycosyltransferases reported to date. Transcripts of both CGT genes were found to concentrate in various plant organs, and particularly in leaves. Our results suggest that di‐C‐glucosyl flavonoid biosynthesis proceeds via a single enzyme using either 2‐hydroxyflavanones or phloretin as a substrate in citrus plants. In addition, Escherichia coli cells expressing CGT genes were found to be capable of producing di‐C‐glucosyl flavonoids, which is promising for commercial production of these valuable compounds.
Article
Plant Journal.91(2):187-198(2017)
journal article
WILEY
2017-07-03
application/pdf
Plant Journal
2
91
187
198
0960-7412
AA10846815
https://soar-ir.repo.nii.ac.jp/record/20550/files/26450120_01.pdf
eng
28370711
https://www.ncbi.nlm.nih.gov/pubmed/28370711
10.1111/tpj.13555
https://doi.org/10.1111/tpj.13555
This is the peer reviewed version of the following article: [Plant Journal.91(2):187-198(2017)], which has been published in final form at [10.1111/tpj.13555]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.