Functional characterization of NES and GES responsible for the biosynthesis of (E)-nerolidol and (E, E)-geranyllinalool in Tripterygium wilfordii

作者：Su, Ping; Hu, Tianyuan; Liu, Yujia; Tong, Yuru; Guan, Hongyu; Zhang, Yifeng; Zhou, Jiawei; Huang, Luqi^*; Gao, Wei^*

来源：Scientific Reports, 2017, 7(1): 40851.

DOI：10.1038/srep40851

• DIPHOSPHATE SYNTHASE
• PLASTID TERPENOIDS
• FLORAL SCENT
• IDENTIFICATION
• GENE
• METABOLISM
• PHYTOENE
• CLONING

Triptolide and celastrol, two principal bioactive compounds in Tripterygium wilfordii, are produced from geranylgeranyl diphosphate (GGPP) and farnesyl diphosphate ((E, E)-FPP) through terpenoid biosynthesis pathway. However, little is known about T. wilfordii terpene synthases which could competitively utilize GGPP and (E, E)-FPP as substrates, producing C-15 and C-20 tertiary alcohols. Here we firstly cloned the genes encoding nerolidol synthase (NES) and geranyllinalool synthases (GES1, GES2), which are responsible for the biosynthesis of (E)-nerolidol and (E, E)-geranyllinalool. In vitro characterization of recombinant TwNES and TwGES1 revealed both were functional enzymes that could catalyze the conversion of (E, E)-FPP and GGPP to (E)-nerolidol and (E, E)-geranyllinalool, which were consistent with the results of yeast fermentation. Biochemical characterization revealed TwNES and TwGES1 had strong dependency for Mg2+, K-m and K-cat/K-m values of TwNES for (E, E)-FPP were 12.700 mu M and 0.029 s(-1)/mu M, and TwGES1 for GGPP were 2.039 mu M and 0.019 s(-1)/mu M. Real-time PCR analysis showed the expression levels of NES and GES1 increased by several fold in the suspension cells treated with alamethicin, indicating TwNES and TwGES1 are likely to utilize GGPP and (E, E)-FPP to generate tertiary alcohols as precursor of plant volatiles, which play important roles in the ecological interactions between T. wilfordii and other organisms.

• 出版日期2017-1-27
• 单位中医学科学院; 首都医科大学; 中国中医科学院