植物类黄酮UDP-糖基转移酶研究进展

doi:10.13560/j.cnki.biotech.bull.1985.2022-0236

摘要/Abstract

摘要：

植物类黄酮化合物是一类重要的天然产物，通常以糖苷的形式存在。尿苷二磷酸糖基转移酶（uridine diphosphate glycosyltransferase，UGT）能够对类黄酮进行糖基化修饰，形成种类丰富的类黄酮糖苷，是许多药用植物中的类黄酮药用活性成分。近年来，随着越来越多的植物基因组被解析，大量参与类黄酮合成的糖基转移酶得以鉴定。本文首先简述了植物UGT的结构特征和家族分类，然后详细综述了植物类黄酮UGT的研究进展，对处于不同家族中的植物类黄酮UGT的修饰位点特异性、以及糖供体和糖受体的特异性进行了全面的归纳和总结，以期为植物类黄酮UGT的结构与功能相关性研究及新植物类黄酮UGT的发掘与鉴定研究奠定基础。

关键词: 类黄酮, 生物合成, 糖基转移酶, 尿苷二磷酸糖基转移酶, 基因家族

Abstract:

Flavonoids are important natural products in plants and usually exist in the form of glycosides. Uridine diphosphate glycosyltransferases（UGTs）can modify flavonoids to form a variety of flavonoid glycosides, which are the active substances of flavonoid medicines in many medical plants. In recent years, as more and more plant genomes have been elucidated, a large number of glycosyltransferases involved in flavonoid synthesis have been identified. In this paper, we firstly introduced the structural features and family classification of plant UGTs, and then reviewed the advances in the study of flavonoid UGTs, had a complete summary on the selectivity of modification sites of plant flavonoid UGT in varied families, as well as the specificity of donors and receptors. It is aimed to lay a foundation for investigating the correlation between structure and function of plant flavonoid UGTs as well as the mining and identification of novel flavonoid UGTs.

Key words: flavonoids, biosynthesis, glycosyltransferase, uridine diphosphate glycosyltransferase, gene family

姚宇, 顾佳珺, 孙超, 申国安, 郭宝林. 植物类黄酮UDP-糖基转移酶研究进展[J]. 生物技术通报, 2022, 38(12): 47-57.

YAO Yu, GU Jia-jun, SUN Chao, SHEN Guo-an, GUO Bao-lin. Advances in Plant Flavonoids UDP-glycosyltransferase[J]. Biotechnology Bulletin, 2022, 38(12): 47-57.

图/表 5

图1 PSPG保守区

Fig. 1 Conserved box of plant secondary product glycosylt-ransferase（PSPG）

表1 植物UGT的底物识别特异性

Table 1 Substrate specificity of plant UGT

组 Group	UGT家族 UGT family	催化底物 Substrate
A	79，91，94	类黄酮、皂苷和细胞分裂素
B	89，96	油菜素甾醇、萜类、类黄酮和苯甲酸盐等
C	90，97
D	73，98，99，702，703，704，705，729
E	70，71，72，88，706，707	ABA、木纤维素、萜类化合物、苯甲酸盐和类黄酮化合物
F	78，77，714	类黄酮
G	85	萜类和玉米素
H	76，710	生长素、邻氨基苯甲酸盐、花青素、苯丙素类和油菜素甾醇
I	83，712
J	87
N	82
K	86
L	74，75，84	类黄酮、苯丙烷和生长素吲哚乙酸
M	92	细胞分裂素
O	93，722	植物激素和细胞分裂素
P	709，720	萜类
Q	95，716	类黄酮
R	708

图2 植物类黄酮UGT和拟南芥UGT系统进化树 3GT：3-O-糖基转移酶；5GT：5-O-糖基转移酶；7GT：7-O-糖基转移酶；3'GT：3'-O-糖基转移酶；GGT：糖基化附着于黄酮苷元的糖基的糖基转移酶。3'GlcT：3'-O-葡糖基转移酶；4'GlcT：4'-O-葡糖基转移酶；3GalT：3-O-半乳糖基转移酶；3RhaT：3-O-鼠李糖基转移酶；5GlcT：5-O-葡糖基转移酶；7GlcT：7-O-葡糖基转移酶；7GAT，7-O-葡糖醛酸转移酶；7RhaT：7-O-葡糖基转移酶；G6''Gt：6''-O-葡糖基转移酶；G2''Gt，G2''GlcT：2''-O-葡糖基转移酶；G6''Rt，G2''RhaT：6''-O-鼠李糖基转移酶

Fig. 2 Phylogenetic analysis of Arabidopsis UGT family and plant flavonoid UGT 3GT：3-O-glycosyltransferase；5GT：5-O-glycosyltransferase；7GT：7-O-glycosyltransferase；3'GT：3'-O-glycosyltransferase；4'GT，4'-O-glycosyltransferase；GGT：glycoside glycosyltransferases；3'GlcT：3'-O-glucosyltransferase；4'GlcT：4'-O-glucosyltransferase；3GalT：3-O-galactosyltransferase；3RhaT：3-O-rhamnosyltransferase；5GlcT：5-O-glucosyltransferase；7GlcT：7-O-glucosyltransferase；7GAT：7-O-glucuronic acid transferase；7RhaT：7-O- rhamnosyltransferase；G6”Gt：6”-O-glucosyltransferase；G2”Gt，G2”GlcT：2”-O-glucosyltransferase；G6”Rt，G2”RhaT：6”-O-rhamnosyltransferase Am：Antirrhinum majus；At：Arabidopsis thaliana；Cm：Citrus maxima；Cp，Citrus paradisi；Cs：Crocus sativus；Cs：Camellia sinensis；Fa：Fragaria× ananassa；Gb：Ginkgo biloba；Gm：Glycine max；Hp：Hieracium pilosella；Ip，Ipomoea purpurea；Lv，Linaria vulgaris；Nm：Nemophila menziesii；Pf：Perilla frutescens；Pg：Punica granatum；Ph：Petunia hybrida；Pl：Pueraria lobata；Sl：Sesamum indicum；Va：Vitis amurensis；Vv：Vitis vinifera

表2 识别植物类黄酮O-位的UGT对底物修饰位点的选择性

Table 2 Specificity of UGT identifying flavonoid O-site to the modification sites of substrates in plants

组Group	UGT家族UGT family	主要修饰位点Modification site
A	79，95，716	GGTs
B	89	7-OH
C	90	4'-OH
D	73	7-OH
E	88，70，71	7-OH（唇形目Lamiales）
F	78	3-OH
L	75，84	5-OH

表3 修饰位点选择不符合所在组规律的植物类黄酮UGT

Table 3 Plant flavonoids UGT with special modified site

组 Group	UGT家族 UGT family	基因ID Gene ID	物种 Species	拉丁名 Latin name	基因登录号 Accession No.	修饰位点 Modification site	底物 Substrate
A	79	PhA3RhaT^[40]	矮牵牛	Petunia hybrida	Q43716.1	3-OH	花青素
A	79	AtUGT79B2^[24]	拟南芥	Arabidopsis thaliana	Q9T080.1	3-OH	花青素
A	95	GbUGT716A1^[42]	银杏	Ginkgo biloba	ASK39400.1	3-OH和7-OH为主，也能修饰3'-OH和4'-OH	黄酮、黄酮醇、异黄酮、没食子和没食子酸黄烷醇
A	95	PgUGT95B2^[29]	石榴	Punica granatum	AZB52139.1	4'-OH	黄酮醇和黄酮
A	95	HpUGT95A1^[41]	绿毛山柳菊	Hieracium pilosella	ACB56927.1	3'-OH	黄酮
C	90	HpUGT90A7^[41]	绿毛山柳菊	Hieracium pilosella	EU561019.1	4'-OH为主，也能修饰7-OH	黄酮醇
E	71	FaGT6^[47]	草莓	Fragaria x ananassa	ABB92748.1	3-OH为主，也能修饰7-OH、4'-OH和3'-OH	黄酮醇为主，也能催化羟基香豆素和萘酚
E	70	CsUGT707B1^[22]	红花	Crocus sativus	CCG85331.1	2''-OH	黄酮醇
E	73	FaGT7^[47]	草莓	Fragaria x ananassa	ABB92749.1	3-OH和4'-OH为主，也能修饰7-OH和3'-OH	黄酮醇、羟基香豆素和萘酚
E	88	GmUGT88E19^[46]	大豆	Glycine max	XP_003533968	3'-OH和7-OH	异黄酮
L	84	NmF4' G7GT^[48]	粉蝶花	Nemophila menziesii	BBA68563.1	4'-OH和7-OH	黄酮

参考文献 68

[1]	Buer CS, Imin N, Djordjevic MA. Flavonoids:new roles for old molecules[J]. J Integr Plant Biol, 2010, 52(1):98-111. doi: 10.1111/j.1744-7909.2010.00905.x URL
[2]	Harborne JB, Williams CA. Advances in flavonoid research since 1992[J]. Phytochemistry, 2000, 55(6):481-504. pmid: 11130659
[3]	Dobrzynska M, Napierala M, Florek E. Flavonoid nanoparticles:a promising approach for cancer therapy[J]. Biomolecules, 2020, 10(9):1268. doi: 10.3390/biom10091268 URL
[4]	Serafini M, Peluso I, Raguzzini A. Flavonoids as anti-inflammatory agents[J]. Proc Nutr Soc, 2010, 69(3):273-278. doi: 10.1017/S002966511000162X pmid: 20569521
[5]	Xiao JB. Dietary flavonoid aglycones and their glycosides:which show better biological significance?[J]. Crit Rev Food Sci Nutr, 2017, 57(9):1874-1905.
[6]	Yonekura-Sakakibara K, Hanada K. An evolutionary view of functional diversity in family 1 glycosyltransferases[J]. Plant J, 2011, 66(1):182-193. doi: 10.1111/j.1365-313X.2011.04493.x URL
[7]	Ross J, Li Y, Lim E, et al. Higher plant glycosyltransferases[J]. Genome Biol, 2001, 2(2): REVIEWS3004.
[8]	Vogt T, Jones P. Glycosyltransferases in plant natural product synthesis:characterization of a supergene family[J]. Trends Plant Sci, 2000, 5(9):380-386. pmid: 10973093
[9]	Shao H, He XZ, Achnine L, et al. Crystal structures of a multifunctional triterpene/flavonoid glycosyltransferase from Medicago truncatula[J]. Plant Cell, 2005, 17(11):3141-3154. pmid: 16214900
[10]	Maharjan R, Fukuda Y, Shimomura N, et al. An ambidextrous polyphenol glycosyltransferase PaGT2 from Phytolacca americana[J]. Biochemistry, 2020, 59(27):2551-2561. doi: 10.1021/acs.biochem.0c00224 pmid: 32525309
[11]	Liu MZ, Wang DD, Li Y, et al. Crystal structures of the C-glycosyltransferase UGT708C1 from buckwheat provide insights into the mechanism of C-glycosylation[J]. Plant Cell, 2020, 32(9):2917-2931. doi: 10.1105/tpc.20.00002 URL
[12]	Hsu TM, Welner DH, Russ ZN, et al. Employing a biochemical protecting group for a sustainable indigo dyeing strategy[J]. Nat Chem Biol, 2018, 14(3):256-261. doi: 10.1038/nchembio.2552 pmid: 29309053
[13]	Wetterhorn KM, Newmister SA, Caniza RK, et al. Crystal structure of Os79(Os04g0206600)from Oryza sativa:a UDP-glucosyltransferase involved in the detoxification of deoxynivalenol[J]. Biochemistry, 2016, 55(44):6175-6186. pmid: 27715009
[14]	Gloster TM. Advances in understanding glycosyltransferases from a structural perspective[J]. Curr Opin Struct Biol, 2014, 28:131-141. doi: 10.1016/j.sbi.2014.08.012 URL
[15]	Bowles D, Lim EK, Poppenberger B, et al. Glycosyltransferases of lipophilic small molecules[J]. Annu Rev Plant Biol, 2006, 57:567-597. pmid: 16669774
[16]	Lairson LL, Henrissat B, Davies GJ, et al. Glycosyltransferases:structures, functions, and mechanisms[J]. Annu Rev Biochem, 2008, 77:521-555. doi: 10.1146/annurev.biochem.76.061005.092322 pmid: 18518825
[17]	McIntosh CA, Owens DK. Advances in flavonoid glycosyltransferase research:integrating recent findings with long-term citrus studies[J]. Phytochem Rev, 2016, 15(6):1075-1091. doi: 10.1007/s11101-016-9460-6 URL
[18]	Wilson AE, Tian L. Phylogenomic analysis of UDP-dependent glycosyltransferases provides insights into the evolutionary landscape of glycosylation in plant metabolism[J]. Plant J, 2019, 100(6):1273-1288. doi: 10.1111/tpj.14514 URL
[19]	Kawai Y, Ono E, Mizutani M. Expansion of specialized metabolism-related superfamily genes via whole genome duplications during angiosperm evolution[J]. Plant Biotechnol, 2014, 31(5):579-584. doi: 10.5511/plantbiotechnology.14.0901a URL
[20]	Caputi L, Malnoy M, Goremykin V, et al. A genome-wide phylogenetic reconstruction of family 1 UDP-glycosyltransferases revealed the expansion of the family during the adaptation of plants to life on land[J]. Plant J, 2012, 69(6):1030-1042. doi: 10.1111/j.1365-313X.2011.04853.x URL
[21]	Zhang F, Guo H, Huang JC, et al. A UV-B-responsive glycosyltransferase, OsUGT706C2, modulates flavonoid metabolism in rice[J]. Sci China Life Sci, 2020, 63(7):1037-1052. doi: 10.1007/s11427-019-1604-3 pmid: 32112268
[22]	Trapero A, Ahrazem O, Rubio-Moraga A, et al. Characterization of a glucosyltransferase enzyme involved in the formation of kaempferol and quercetin sophorosides in Crocus sativus[J]. Plant Physiol, 2012, 159(4):1335-1354. doi: 10.1104/pp.112.198069 pmid: 22649274
[23]	Knoch E, Sugawara S, Mori T, et al. UGT79B31 is responsible for the final modification step of pollen-specific flavonoid biosynthesis in Petunia hybrida[J]. Planta, 2018, 247(4):779-790. doi: 10.1007/s00425-017-2822-5 pmid: 29214446
[24]	Li P, Li YJ, Zhang FJ, et al. The Arabidopsis UDP-glycosyltransferases UGT79B2 and UGT79B3, contribute to cold, salt and drought stress tolerance via modulating anthocyanin accumulation[J]. Plant J, 2017, 89(1):85-103. doi: 10.1111/tpj.13324 URL
[25]	Casas MI, Falcone-Ferreyra ML, Jiang N, et al. Identification and characterization of maize salmon silks genes involved in insecticidal maysin biosynthesis[J]. Plant Cell, 2016, 28(6):1297-1309. doi: 10.1105/tpc.16.00003 URL
[26]	Jung SC, Kim W, Park SC, et al. Two ginseng UDP-glycosyltransferases synthesize ginsenoside Rg3 and Rd[J]. Plant Cell Physiol, 2014, 55(12):2177-2188. doi: 10.1093/pcp/pcu147 URL
[27]	Wu BP, Gao LX, Gao J, et al. Genome-wide identification, expression patterns, and functional analysis of UDP glycosyltransferase family in peach(Prunus persica L. batsch)[J]. Front Plant Sci, 2017, 8:389.
[28]	Irmisch S, Jancsik S, Man Saint Yuen M, et al. Complete biosynthesis of the anti-diabetic plant metabolite montbretin A[J]. Plant Physiol, 2020, 184(1):97-109. doi: 10.1104/pp.20.00522 pmid: 32647038
[29]	Wilson AE, Wu S, Tian L. PgUGT95B2 preferentially metabolizes flavones/flavonols and has evolved independently from flavone/flavonol UGTs identified in Arabidopsis thaliana[J]. Phytochemistry, 2019, 157:184-193. doi: S0031-9422(18)30304-2 pmid: 30419412
[30]	Nagatomo Y, Usui S, Ito T, et al. Purification, molecular cloning and functional characterization of flavonoid C-glucosyltransferases from Fagopyrum esculentum M. (buckwheat)cotyledon[J]. Plant J, 2014, 80(3):437-448. doi: 10.1111/tpj.12645 URL
[31]	Hofer B. Recent developments in the enzymatic O-glycosylation of flavonoids[J]. Appl Microbiol Biotechnol, 2016, 100(10):4269-4281. doi: 10.1007/s00253-016-7465-0 pmid: 27029191
[32]	Gachon CMM, Langlois-Meurinne M, Saindrenan P. Plant secondary metabolism glycosyltransferases:the emerging functional analysis[J]. Trends Plant Sci, 2005, 10(11):542-549. doi: 10.1016/j.tplants.2005.09.007 URL
[33]	Rojas Rodas F, Rodriguez TO, Murai Y, et al. Linkage mapping, molecular cloning and functional analysis of soybean gene Fg2 encoding flavonol 3-O-glucoside(1→6)rhamnosyltransferase[J]. Plant Mol Biol, 2014, 84(3):287-300. doi: 10.1007/s11103-013-0133-1 URL
[34]	Di SK, Yan F, Rodas FR, et al. Linkage mapping, molecular cloning and functional analysis of soybean gene Fg3 encoding flavonol 3-O-glucoside(1→2)glucosyltransferase[J]. BMC Plant Biol, 2015, 15:126. doi: 10.1186/s12870-015-0504-7 URL
[35]	Rojas Rodas F, Di SK, Murai Y, et al. Cloning and characterization of soybean gene Fg1 encoding flavonol 3-O-glucoside/galactoside(1→6)glucosyltransferase[J]. Plant Mol Biol, 2016, 92(4/5):445-456. doi: 10.1007/s11103-016-0523-2 URL
[36]	Masada S, Terasaka K, Oguchi Y, et al. Functional and structural characterization of a flavonoid glucoside 1, 6-glucosyltransferase from Catharanthus roseus[J]. Plant Cell Physiol, 2009, 50(8):1401-1415. doi: 10.1093/pcp/pcp088 URL
[37]	Yonekura-Sakakibara K, Nakabayashi R, Sugawara S, et al. A flavonoid 3-O-glucoside:2''-O-glucosyltransferase responsible for terminal modification of pollen-specific flavonols in Arabidopsis thaliana[J]. Plant J, 2014, 79(5):769-782. doi: 10.1111/tpj.12580 URL
[38]	Morita Y, Hoshino A, Kikuchi Y, et al. Japanese morning glory dusky mutants displaying reddish-brown or purplish-gray flowers are deficient in a novel glycosylation enzyme for anthocyanin biosynthesis, UDP-glucose:anthocyanidin 3-O-glucoside-2''-O-glucosyltransferase, due to 4-bp insertions in the gene[J]. Plant J, 2005, 42(3):353-363. pmid: 15842621
[39]	Frydman A, Weisshaus O, Bar-Peled M, et al. Citrus fruit bitter flavors:isolation and functional characterization of the gene Cm1, 2RhaT encoding a 1, 2 rhamnosyltransferase, a key enzyme in the biosynthesis of the bitter flavonoids of citrus[J]. Plant J, 2004, 40(1):88-100. pmid: 15361143
[40]	Kroon J, Souer E, de Graaff A, et al. Cloning and structural analysis of the anthocyanin pigmentation locus Rt of Petunia hybrida:characterization of insertion sequences in two mutant alleles[J]. Plant J, 1994, 5(1):69-80. pmid: 8130799
[41]	Witte S, Moco S, Vervoort J, et al. Recombinant expression and functional characterisation of regiospecific flavonoid glucosyltransferases from Hieracium pilosella L[J]. Planta, 2009, 229(5):1135-1146. doi: 10.1007/s00425-009-0902-x pmid: 19238428
[42]	Su XJ, Shen GA, Di SK, et al. Characterization of UGT716A1 as a multi-substrate UDP:flavonoid glucosyltransferase gene in Ginkgo biloba[J]. Front Plant Sci, 2017, 8:2085. doi: 10.3389/fpls.2017.02085 URL
[43]	Yonekura-Sakakibara K, Tohge T, Niida R, et al. Identification of a flavonol 7-O-rhamnosyltransferase gene determining flavonoid pattern in Arabidopsis by transcriptome coexpression analysis and reverse genetics[J]. J Biol Chem, 2007, 282(20):14932-14941. doi: 10.1074/jbc.M611498200 pmid: 17314094
[44]	Jones P, Messner B, Nakajima JI, et al. UGT73C6 and UGT78D1, glycosyltransferases involved in flavonol glycoside biosynthesis in Arabidopsis thaliana[J]. J Biol Chem, 2003, 278(45):43910-43918. doi: 10.1074/jbc.M303523200 pmid: 12900416
[45]	Noguchi A, Horikawa M, Fukui Y, et al. Local differentiation of sugar donor specificity of flavonoid glycosyltransferase in Lamiales[J]. Plant Cell, 2009, 21(5):1556-1572. doi: 10.1105/tpc.108.063826 pmid: 19454730
[46]	Yin QG, Shen GA, Di SK, et al. Genome-wide identification and functional characterization of UDP-glucosyltransferase genes involved in flavonoid biosynthesis in Glycine max[J]. Plant Cell Physiol, 2017, 58(9):1558-1572. doi: 10.1093/pcp/pcx081 pmid: 28633497
[47]	Griesser M, Vitzthum F, Fink B, et al. Multi-substrate flavonol O-glucosyltransferases from strawberry(Fragaria × ananassa)achene and receptacle[J]. J Exp Bot, 2008, 59(10):2611-2625. doi: 10.1093/jxb/ern117 pmid: 18487633
[48]	Okitsu N, Matsui K, Horikawa M, et al. Identification and characterization of novel Nemophila menziesii flavone glucosyltransferases that catalyze biosynthesis of flavone 7, 4'-O-diglucoside, a key component of blue metalloanthocyanins[J]. Plant Cell Physiol, 2018, 59(10):2075-2085. doi: 10.1093/pcp/pcy129 pmid: 29986079
[49]	Ono E, Fukuchi-Mizutani M, Nakamura N, et al. Yellow flowers generated by expression of the aurone biosynthetic pathway[J]. Proc Natl Acad Sci USA, 2006, 103(29):11075-11080. doi: 10.1073/pnas.0604246103 URL
[50]	Ono E, Nakayama T. Molecular breeding of novel yellow flowers by engineering the aurone biosynthetic pathway[J]. Transgen Plant J, 2007, 1(1):66-80.
[51]	Li J, Li ZB, Li CF, et al. Molecular cloning and characterization of an isoflavone 7-O-glucosyltransferase from Pueraria Lobata[J]. Plant Cell Rep, 2014, 33(7):1173-1185. doi: 10.1007/s00299-014-1606-7 pmid: 24700248
[52]	Tohge T, Nishiyama Y, Hirai MY, et al. Functional genomics by integrated analysis of metabolome and transcriptome of Arabidopsis plants over-expressing an MYB transcription factor[J]. Plant J, 2005, 42(2):218-235. pmid: 15807784
[53]	Yonekura-Sakakibara K, Tohge T, Matsuda F, et al. Comprehensive flavonol profiling and transcriptome coexpression analysis leading to decoding gene-metabolite correlations in Arabidopsis[J]. Plant Cell, 2008, 20(8):2160-2176. doi: 10.1105/tpc.108.058040 pmid: 18757557
[54]	Yin RH, Messner B, Faus-Kessler T, et al. Feedback inhibition of the general phenylpropanoid and flavonol biosynthetic pathways upon a compromised flavonol-3-O-glycosylation[J]. J Exp Bot, 2012, 63(7):2465-2478. doi: 10.1093/jxb/err416 pmid: 22249996
[55]	Miller KD, Guyon V, Evans JN, et al. Purification, cloning, and heterologous expression of a catalytically efficient flavonol 3-O-galactosyltransferase expressed in the male gametophyte of Petunia hybrida[J]. J Biol Chem, 1999, 274(48):34011-34019. doi: 10.1074/jbc.274.48.34011 pmid: 10567367
[56]	Devaiah SP, Owens DK, Sibhatu MB, et al. Identification, recombinant expression, and biochemical analysis of putative secondary product glucosyltransferases from Citrus paradisi[J]. J Agric Food Chem, 2016, 64(9):1957-1969. doi: 10.1021/acs.jafc.5b05430 URL
[57]	Birchfield AS, McIntosh CA. The effect of recombinant tags on Citrus paradisi flavonol-specific 3-O glucosyltransferase activity[J]. Plants(Basel), 2020, 9(3):402.
[58]	Zhao MY, Jin JY, Gao T, et al. Glucosyltransferase CsUGT78A14 regulates flavonols accumulation and reactive oxygen species scavenging in response to cold stress in Camellia sinensis[J]. Front Plant Sci, 2019, 10:1675. doi: 10.3389/fpls.2019.01675 pmid: 31929783
[59]	He XQ, Huang RH, Liu LP, et al. CsUGT78A15 catalyzes the anthocyanidin 3-O-galactoside biosynthesis in tea plants[J]. Plant Physiol Biochem, 2021, 166:738-749. doi: 10.1016/j.plaphy.2021.06.029 URL
[60]	Ono E, Homma Y, Horikawa M, et al. Functional differentiation of the glycosyltransferases that contribute to the chemical diversity of bioactive flavonol glycosides in grapevines(Vitis vinifera)[J]. Plant Cell, 2010, 22(8):2856-2871. doi: 10.1105/tpc.110.074625 URL
[61]	He F, Chen WK, Yu KJ, et al. Molecular and biochemical characterization of the UDP-glucose:anthocyanin 5-O-glucosyltransferase from Vitis amurensis[J]. Phytochemistry, 2015, 117:363-372. doi: 10.1016/j.phytochem.2015.06.023 URL
[62]	Dai LH, Hu YM, Chen CC, et al. Flavonoid C-glycosyltransferases:function, evolutionary relationship, catalytic mechanism and protein engineering[J]. Chembioeng Rev, 2021, 8(1):15-26. doi: 10.1002/cben.202000009 URL
[63]	Tegl G, Nidetzky B. Leloir glycosyltransferases of natural product C-glycosylation:structure, mechanism and specificity[J]. Biochem Soc Trans, 2020, 48(4):1583-1598. doi: 10.1042/BST20191140 URL
[64]	Mashima K, Hatano M, Suzuki H, et al. Identification and characterization of apigenin 6-C-glucosyltransferase involved in biosynthesis of isosaponarin in wasabi(Eutrema japonicum)[J]. Plant Cell Physiol, 2019, 60(12):2733-2743. doi: 10.1093/pcp/pcz164 pmid: 31418788
[65]	Ren ZY, Ji XY, Jiao ZB, et al. Functional analysis of a novel C-glycosyltransferase in the orchid Dendrobium catenatum[J]. Hortic Res, 2020, 7:111. doi: 10.1038/s41438-020-0330-4 URL
[66]	He JB, Zhao P, Hu ZM, et al. Molecular and structural characterization of a promiscuous C-glycosyltransferase from Trollius chinensis[J]. Angew Chem Int Ed Engl, 2019, 58(33):11513-11520. doi: 10.1002/anie.201905505 URL
[67]	Wang X, Li CF, Zhou C, et al. Molecular characterization of the C-glucosylation for puerarin biosynthesis in Pueraria Lobata[J]. Plant J, 2017, 90(3):535-546. doi: 10.1111/tpj.13510 URL
[68]	He XZ, Blount JW, Ge SJ, et al. A genomic approach to isoflavone biosynthesis in kudzu(Pueraria Lobata)[J]. Planta, 2011, 233(4):843-855. doi: 10.1007/s00425-010-1344-1 URL