中文摘要：

三七总皂苷为三七主要的药用活性成分,但因其产量较低,使其药用价值很难得到推广。三七皂苷和甾醇分别经达玛烯二醇合酶（DS）和环阿屯醇合酶（CAS）的催化共同的前体物质2, 3-氧化鲨烯生成。利用Gateway技术建立了CAS基因的RNA 干扰（RNAi）表达载体,并利用农杆菌介导法将其转移并整合至三七基因组中,由此方法抑制CAS的表达,阻断植物甾醇的合成,间接增加三七皂苷的产量。

英文摘要：

PNS （panax notoginseng saponins） is the main medical bioactive component from Panax notoginseng. The medical value of PNS cannot be extended because of its low production. From previous studies inferred that both PNS and phytosterol are derived from the precursor 2,3-oxidosqualene. The enzyme cycloartenol synthase （CAS） and dammarenediol synthase （DS） are responsible for PNS and phytosterol biosynthesis, respectively. The CAS RNAi expression vector is established by Gateway technology. By the way of agrobacterium-mediated method, the vector was transferred and integrated into the Panax notoginseng genome to suppress the expression of CAS, block the synthesis of phytosterol, and increase the PNS production indirectly.