Jo Hye-Jeong, Han Jung Yeon, Hwang Hwan-Su, Choi Yong Eui
Department of Forest Resources, College of Forest and Environmental Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea.
Department of Forest Resources, College of Forest and Environmental Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea.
Phytochemistry. 2017 Mar;135:53-63. doi: 10.1016/j.phytochem.2016.12.011. Epub 2016 Dec 21.
Siberian ginseng (Eleutherococcus senticosus) is a woody medical shrub belonging to the Araliaceae family. E. senticosus contains various types of saponins, including oleanane, noroleanane, lupane, and 3,4-secolupane types, depending on the aglycone structure. Oleanane-type triterpenes are the major saponin components in E. senticosus. Two enzymes (β-amyrin synthase and β-amyrin 28-oxidase) are essential for oleanane-type saponin biosynthesis from 2,3-oxidosqualene. In the present study, two full-length cDNAs encoding EsBAS and CYP716A244 were isolated based on transcriptomics analysis of plant leaves. Both β-amyrin synthase (EsBAS) and β-amyrin 28-oxidase (CYP716A244), isolated from E. senticosus, were functionally characterised. β-amyrin production was confirmed by heterologous expression of the EsBAS gene in yeast and tobacco. Oleanolic acid production was confirmed by co-expression of both EsBAS and CYP716A244 in engineered yeast and transgenic tobacco.
西伯利亚人参（刺五加）是一种属于五加科的木本药用灌木。根据苷元结构，刺五加含有多种类型的皂苷，包括齐墩果烷型、去甲齐墩果烷型、羽扇豆烷型和3,4-裂羽扇豆烷型。齐墩果烷型三萜是刺五加中的主要皂苷成分。两种酶（β-香树脂醇合酶和β-香树脂醇28-氧化酶）对于从2,3-氧化角鲨烯生物合成齐墩果烷型皂苷至关重要。在本研究中，基于对植物叶片的转录组学分析，分离出了两个编码EsBAS和CYP716A244的全长cDNA。从刺五加中分离出的β-香树脂醇合酶（EsBAS）和β-香树脂醇28-氧化酶（CYP716A244）均进行了功能表征。通过在酵母和烟草中对EsBAS基因进行异源表达，证实了β-香树脂醇的产生。通过在工程酵母和转基因烟草中共表达EsBAS和CYP716A244，证实了齐墩果酸的产生。
