过量表达DXR基因提高青蒿中青蒿素的含量

Enhanced Artemisinin Content in Artemisia annua L. by Over-Expressing DXR Gene

青蒿素是从菊科植物青蒿地上部分提取的一种含过氧桥结构的倍半萜类物质,是治疗疟疾最有效的药物。青蒿素在青蒿中的含量较低。为了提高青蒿素含量,根据GenBank上公布的青蒿素生物合成途径中关键酶基因DXR的编码区序列,从青蒿叶片cDNA中克隆了DXR基因并将其构建到植物表达载体pFSN中。通过根癌农杆菌介导转化青蒿,获得14株转基因青蒿,经PCR鉴定外源基因已插入青蒿基因组中。采用HPLC-ELSD方法对青蒿素含量进行测定,转基因青蒿中青蒿素含量最高达到野生型的2.84倍,证明了过量表达DXR基因能够有效提高青蒿中青蒿素的含量。

Artemisinin, a type of sesquiterpene with peroxide bridge structure, extracted from the aerial part of Artemisia annua L,is now the most effective drug for malaria. However, the artemisinin content in A. annua is very low. In order to increase artemisinin content, DXR was over-expressed in A. annua. According to the published sequence on GenBank, specific primers were designed to clone DXR which was inserted into plant expression vector pFSN. The recombinant vector was applied to genetically transform A. annua by using an Agrobacterium tumefaciens-mediated method. PCR detections demonstrated the transgenic statuses of 14 independent plants transformed with DXR. HPLC-ELSD analysis showed that the artemisinin content of the transgenic plants had a 2. 84-fold increase in comparison with those of the wild type, which revealed the effectiveness of over-expressing DXR gene in enhancing artemisinin content.