Unravelling the consecutive glycosylation and methylation of flavonols in peach in response to UV‐B irradiation

Abstract

Flavonol glycosides are bioactive compounds important for plant defence and human nutrition. Glycosylation and methylation play an important role in enriching the diversity of flavonols in response to the environment. Peach flowers and fruit are rich in flavonol diglycosides such as isorhamnetin 3-O-rutinoside (I3Rut), kaempferol 3-Orutinoside and quercetin 3-O-rutinoside, and flavonol monoglycosides such as I 3-Oglucoside and Q 3-O-galactoside. UV-B irradiation of fruit significantly induced

Identification of UDP-rhamnosyltransferases and UDP-galactosyltransferase involved in flavonol glycosylation inMorella rubra

“…N. benthamiana could serve as a plant host for metabolic engineering to produce plant metabolites with complex structure. However, heterologous plant systems for metabolic engineering may have a problem, which is the potential production of non-target compounds, while overexpressing transcription factors that control specific metabolite pathways could direct the flux to the target pathways and enhance production levels [ 40 , 41 ]. For example, in the present study, by coexpressing with the flavonol-specific transcription factor MrMYB12, large amounts of target flavonol rhamnosides and galactosides were produced in N. benthamiana .…”

Genome-wide analysis of UDP-glycosyltransferase gene family and identification of members involved in flavonoid glucosylation in Chinese bayberry (Morella rubra)

“…UV-B stress is an efficient treatment for induction of flavonoid glycosides accumulation in plants ( Kolb et al, 2001 ; Stracke et al, 2010 ; Henry-Kirk et al, 2018 ; Xie et al, 2022 ). Therefore, we carried out UV-B treatment for investigation and identification of MrUGTs involved in flavonoid glucosylation ( Figure 5 ).…”

“…This makes it possible to predict functional UGTs by phylogenetic analysis. For example, UGT members in group A were considered to be related to biosynthesis of flavonoid disaccharides, and examples include Cis1,6RhaT ( Frydman et al, 2004 ), Cm1,2RhaT ( Frydman et al, 2013 ), and PpUGT79AK6 ( Xie et al, 2022 ). UGT members in group O usually exhibited activity toward plant hormone zeatin.…”

“…In model plant Arabidopsis , AtUGT78D2 was identified as flavonoid 3- O -glucosyltransferase by enzymatic activity analysis and T-DNA-inserted mutants ( Tohge et al, 2005 ). Recently, PpUGT78T3 was identified as UDP-glucosyltransferase involved in regulation of flavonol glucosides in response to UV-B ( Xie et al, 2022 ).…”

“…Amino acids in PSPG-box were important for glycosyl transfer activity of UGTs ( Shao et al, 2005 ; Offen et al, 2006 ; Osmani et al, 2009 ). For example, last amino acid residue of PSPG-box for UDP-glucosyltransferases usually was glutamine (Gln), and examples include VvGT1 ( Ford et al, 1998 ), MdUGT71B1 ( Xie et al, 2020 ), and PpUGT78T3 ( Xie et al, 2022 ). However, other amino acids could also influence UGT sugar donor preference and more UGTs with different functions should be identified to elucidate the mechanism of sugar donor preference of UGTs.…”