Nelumbo nucifera, also known as sacred lotus, is a perennial aquatic plant which has been cultivated for thousands of years in China. According to the “Chinese Pharmacopoeia”, its leaf, rhizome node, seed, plumule, stamen, and tori can all be used as medicine with different medicinal effects.
Flavonoid C-glycosides in the lotus plumule have received intense attention recently due to the extensive variety including many kinds of flavonoid di-C-glycosides. Previous studies mainly focused on the identification and pharmacological activity of the flavonoid C-glycosides, but to date, there is very little information about the molecular mechanism of flavonoid C-glycosides biosynthesis.
In a study just published in The Plant Journal, Professor Liangsheng Wang's team from the Institute of Botany, Chinese Academy of Sciences cloned and identified two glycosyltransferases, i.e. UGT708N1 and UGT708N2, which are involved in the biosynthesis of flavone C-glycosides.
In vitro and in vivo evidences suggested that UGT708N1 and UGT708N2 can C-glycosylate 2-hydroxyflavanones and 2-hydroxynaringenin C-glucoside, forming flavone mono-C-glycosides and di-C-glycosides after dehydration, respectively.
Moreover, enzyme assays using cell-free extracts of lotus plumule suggested that flavone di-C-glycosides were biosynthesized through sequentially C-glucosylating and C-arabinosylating/C-xylosylating 2-hydroxynaringenin.
Taken together, this study provides novel insights into the biosynthesis of flavonoid di-C-glycosides by proposing a new flavone C-glycosides biosynthetic pathway of N. nucifera and identifying a novel UGT (UGT708N2) that specifically catalyzes the second glycosylation in which a wide range of sugar donors including arabinose and xylose can be utilized.
"These enzymes provide us with a novel insight into the biosynthetic pathway of flavonoid C-glycosides in plants considering lotus is an ancient angiosperm. Because the content and variety of flavonoid C-glycosides is quite high in lotus plumule, this part could be considered as an enzyme reserve for synthetic biology study of flavonoid C-glycosides." said Prof. Liangsheng Wang, the group leader of this team.
Lotus plumule and flower tepal at 5 different developmental stages.
Articlelink: https://doi.org/10.1111/tpj.15168
Email: wanglsh@ibcas.ac.cn
liucheng@ibcas.ac.cn
Institute of Botany, Chinese Academy of Sciences
Nelumbo nucifera, also known as sacred lotus, is a perennial aquatic plant which has been cultivated for thousands of years in China. According to the “Chinese Pharmacopoeia”, its leaf, rhizome node, seed, plumule, stamen, and tori can all be used as medicine with different medicinal effects.
Flavonoid C-glycosides in the lotus plumule have received intense attention recently due to the extensive variety including many kinds of flavonoid di-C-glycosides. Previous studies mainly focused on the identification and pharmacological activity of the flavonoid C-glycosides, but to date, there is very little information about the molecular mechanism of flavonoid C-glycosides biosynthesis.
In a study just published in The Plant Journal, Professor Liangsheng Wang's team from the Institute of Botany, Chinese Academy of Sciences cloned and identified two glycosyltransferases, i.e. UGT708N1 and UGT708N2, which are involved in the biosynthesis of flavone C-glycosides.
In vitro and in vivo evidences suggested that UGT708N1 and UGT708N2 can C-glycosylate 2-hydroxyflavanones and 2-hydroxynaringenin C-glucoside, forming flavone mono-C-glycosides and di-C-glycosides after dehydration, respectively.
Moreover, enzyme assays using cell-free extracts of lotus plumule suggested that flavone di-C-glycosides were biosynthesized through sequentially C-glucosylating and C-arabinosylating/C-xylosylating 2-hydroxynaringenin.
Taken together, this study provides novel insights into the biosynthesis of flavonoid di-C-glycosides by proposing a new flavone C-glycosides biosynthetic pathway of N. nucifera and identifying a novel UGT (UGT708N2) that specifically catalyzes the second glycosylation in which a wide range of sugar donors including arabinose and xylose can be utilized.
"These enzymes provide us with a novel insight into the biosynthetic pathway of flavonoid C-glycosides in plants considering lotus is an ancient angiosperm. Because the content and variety of flavonoid C-glycosides is quite high in lotus plumule, this part could be considered as an enzyme reserve for synthetic biology study of flavonoid C-glycosides." said Prof. Liangsheng Wang, the group leader of this team.
Lotus plumule and flower tepal at 5 different developmental stages.
Articlelink: https://doi.org/10.1111/tpj.15168
Email: wanglsh@ibcas.ac.cn
liucheng@ibcas.ac.cn
Institute of Botany, Chinese Academy of Sciences