目的 刺五加三萜皂苷是我国传统中药刺五加的主要活性成分之一，具有抗炎、抗癌、抗疲劳、抗氧化等多种功效。但由于刺五加自然资源缺乏，难以满足对三萜皂苷的需求，急需寻求可持续资源利用新模式。目前，生物合成已成为植物次生代谢物积累的重要途径，为此，探寻出刺五加三萜皂苷的生物合成途径具有重要意义。方法 本文通过同源搜索和系统发育分析，预测并克隆了刺五加三萜皂苷合成途径中关键基因EsOSC5，并通过农杆菌介导的烟草瞬时表达实验，获得代谢产物；利用GC-MS检测其次生代谢产物并确定EsOSC5基因功能。结果 挖掘并克隆出片段大小为2286 bp的EsOSC5基因；EsOSC5基因转化烟草的瞬时表达实验及GC-MS次生代谢产物检测数据表明，β-香树脂醇为该基因的代谢产物。结论 EsOSC5基因可促进刺五加β-香树脂醇（三萜皂苷前体）的合成积累，该基因为刺五加β-香树脂醇合酶基因。

Objective Triterpene saponins of Eleutherococcus senticosus is one of active compounds of Eleutherococcus senticosus, a traditional medicinal plant in China. It has many effects, such as anti-inflammatory, anti-cancer, anti-fatigue, anti-oxidation and so on. However, due to the lack of natural resources, it is difficult to extract a large number of triterpene saponins from Eleutherococcus senticosus, so it is urgent to find a new model of sustainable resource utilization. At present, biosynthesis has become an important pathway for the accumulation of plant secondary metabolites. Therefore, it is of great significance to explore the biosynthesis pathway of triterpene saponins in Eleutherococcus senticosus.Methods In this research, EsOSC who is important in the triterpene saponin synthesis pathway of Eleutherococcus senticosus was predicted, cloned and its function was verified by transient expression experiment, which provided a theoretical basis for the analysis of the triterpene saponin biosynthesis pathway of Eleutherococcus senticosus, and through molecular technology to improve the accumulation of triterpene saponins in the process of reproduction. Through homology search and phylogenetic analysis, the EsOSC gene was excavated, and the metabolites were obtained by PCR cloning and agrobacterium mediated transient expression experiment in tobacco; GC-MS was used to detect its secondary metabolites and determine the function of EsOSC. The fragment with the size of 2286 bp was excavated and cloned EsOSC5, which was similar in the evolution of β-amyrin synthase; The transient expression experiment of EsOSC5 transformed tobacco and the detection data of secondary metabolites by GC-MS showed that, β-amyrin is the metabolite of this gene.Conclusion EsOSC5 can promote β-amyrin in Eleutherococcus senticosus. The gene is β-amyrin synthase of Eleutherococcus senticosus.

东北林业大学中央高校基本科研业务费专项资金项目（2572020BD01）：刺五加基因组测序及重要活性成分相关基因的挖掘，负责人：华欣。