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Plant Physiol

Title:		Volatile Glycosylation in Tea Plants: Sequential Glycosylations for the Biosynthesis of Aroma beta-Primeverosides Are Catalyzed by Two Camellia sinensis Glycosyltransferases
Author(s):		Ohgami S; Ono E; Horikawa M; Murata J; Totsuka K; Toyonaga H; Ohba Y; Dohra H; Asai T; Matsui K; Mizutani M; Watanabe N; Ohnishi T;
Address:		"Graduate School of Agriculture (S.O., K.T., Y.O., T.A., T.O.) and Research Institute of Green Science and Technology (H.D., T.O.), Shizuoka University, Shizuoka 422-8529, Japan;Research Institute, Suntory Global Innovation Center, Shimamoto, Mishima, Osaka 618-8503, Japan (E.O., H.T.);Bioorganic Research Institute, Suntory Foundation for Life Sciences, Shimamoto, Mishima, Osaka 618-8503, Japan (M.H., J.M.);Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan (K.M.);Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan (M.M.); andGraduate School of Engineering, Shizuoka University, Hamamatsu 432-8561, Japan (N.W.). Graduate School of Agriculture (S.O., K.T., Y.O., T.A., T.O.) and Research Institute of Green Science and Technology (H.D., T.O.), Shizuoka University, Shizuoka 422-8529, Japan;Research Institute, Suntory Global Innovation Center, Shimamoto, Mishima, Osaka 618-8503, Japan (E.O., H.T.);Bioorganic Research Institute, Suntory Foundation for Life Sciences, Shimamoto, Mishima, Osaka 618-8503, Japan (M.H., J.M.);Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan (K.M.);Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan (M.M.); andGraduate School of Engineering, Shizuoka University, Hamamatsu 432-8561, Japan (N.W.) eiichiro_ono@suntory.co.jp dtonish@ipc.shizuoka.ac.jp"
Journal Title:		Plant Physiol
Year:		2015
Volume:		20150428
Issue:		2
Page Number:		464 - 477
DOI:		10.1104/pp.15.00403
ISSN/ISBN:		1532-2548 (Electronic) 0032-0889 (Print) 0032-0889 (Linking)
Abstract:		"Tea plants (Camellia sinensis) store volatile organic compounds (VOCs; monoterpene, aromatic, and aliphatic alcohols) in the leaves in the form of water-soluble diglycosides, primarily as beta-primeverosides (6-O-beta-D-xylopyranosyl-beta-D-glucopyranosides). These VOCs play a critical role in plant defenses and tea aroma quality, yet little is known about their biosynthesis and physiological roles in planta. Here, we identified two UDP-glycosyltransferases (UGTs) from C. sinensis, UGT85K11 (CsGT1) and UGT94P1 (CsGT2), converting VOCs into beta-primeverosides by sequential glucosylation and xylosylation, respectively. CsGT1 exhibits a broad substrate specificity toward monoterpene, aromatic, and aliphatic alcohols to produce the respective glucosides. On the other hand, CsGT2 specifically catalyzes the xylosylation of the 6'-hydroxy group of the sugar moiety of geranyl beta-D-glucopyranoside, producing geranyl beta-primeveroside. Homology modeling, followed by site-directed mutagenesis of CsGT2, identified a unique isoleucine-141 residue playing a crucial role in sugar donor specificity toward UDP-xylose. The transcripts of both CsGTs were mainly expressed in young leaves, along with beta-primeverosidase encoding a diglycoside-specific glycosidase. In conclusion, our findings reveal the mechanism of aroma beta-primeveroside biosynthesis in C. sinensis. This information can be used to preserve tea aroma better during the manufacturing process and to investigate the mechanism of plant chemical defenses"
Keywords:		"*Biocatalysis Camellia sinensis/*enzymology/genetics Gene Expression Regulation, Enzymologic Glycosides/*biosynthesis/chemistry Glycosylation Glycosyltransferases/genetics/*metabolism Kinetics Molecular Sequence Data Mutagenesis Organ Specificity Phylogen;"
Notes:		"MedlineOhgami, Shoji Ono, Eiichiro Horikawa, Manabu Murata, Jun Totsuka, Koujirou Toyonaga, Hiromi Ohba, Yukie Dohra, Hideo Asai, Tatsuo Matsui, Kenji Mizutani, Masaharu Watanabe, Naoharu Ohnishi, Toshiyuki eng Research Support, Non-U.S. Gov't 2015/04/30 Plant Physiol. 2015 Jun; 168(2):464-77. doi: 10.1104/pp.15.00403. Epub 2015 Apr 28"