Genome-wide identification of UDP-glycosyltransferases in the tea plant (Camellia sinensis) and their biochemical and physiological functions

Abstract

Tea (Camellia sinensis) has been an immensely important commercially grown crop for decades. This is due to the presence of essential nutrients and plant secondary metabolites that exhibit beneficial health effects. UDP-glycosyltransferases (UGTs) play an important role in the diversity of such secondary metabolites by catalysing the transfer of an activated sugar donor to acceptor molecules, and thereby creating a huge variety of glycoconjugates. Only in recent years, thanks to the sequencing of the tea plant genome, have there been increased efforts to characterise the UGTs in C. sinensis to gain an understanding of their physiological role and biotechnological potential. Based on the conserved plant secondary product glycosyltransferase (PSPG) motif and the catalytically active histidine in the active site, UGTs of family 1 in C. sinensis are identified here, and shown to cluster into 21 groups in a phylogenetic tree. Building on this, our current understanding of recently characterised C. sinensis UGTs (CsUGTs) is highlighted and a discussion on future perspectives made.

Characterization of CsUGT73AC15 as a Multifunctional Glycosyltransferase Impacting Flavonol Triglycoside Biosynthesis in Tea Plants

“…Several UGTs with flavonoid catalytic activity have been characterized in tea plants . Most are associated with the synthesis of monoglycosides, such as flavonol 3- O -glucosyltransferase (CsUGT78A14 and CsUGT72AM1), flavonol 3- O -galactosyltransferase (CsUGT78A15), anthocyanidin 3- O -galactosyltransferase (CsUGT78A15), and flavonoid 7- O -glycosyltransferase (CsUGT75L12 and CsUGT74Y1). ,− Additionally, UGTs like CsUGT73A20 and CsUGT79B28 are capable of catalyzing the formation of flavonol diglycosides. , However, our understanding of UGTs involved in the formation of flavonoid triglycosides in tea plants remains limited, which presents a significant gap in our knowledge of these complex biosynthetic pathways.…”

Discovery, characterization, and comparative analysis of new UGT72 and UGT84 family glycosyltransferases

“…Uridine diphosphate (UDP)-dependent glycosyltransferases (UGTs) play a pivotal role in the natural glycosylation and biosynthesis of various phenolic glycosides by transferring UDP-sugars to acceptor substrates 7 – 10 . The lack of well-characterized UGT-catalyzed transformations limits the practical usage of these enzymes, which presents the need for the discovery of new catalytic activities 11 – 13 .…”