青蒿素是目前疗效最好的抗疟药物，其需求量大，但青蒿中含量极低。根据青蒿素合成部位的复杂性，可以推测青蒿素合成中存在代谢产物的转运，这些代谢产物转运机制的研究对植物代谢工程改良青蒿具有重要意义。但是青蒿素合成途径中代谢产物的转运机制尚未被报道。申请人前期筛选到参与青蒿素合成的PDR类转运蛋白（AaPDR1，AaPDR2和AaPDR4）。生物信息学分析，转基因青蒿基因表达，代谢产物分析和酵母突变体转运等实验暗示分泌型腺毛中特异表达的AaPDR1参与青蒿素直接前体物质二氢青蒿酸的转运；AaPDR2和AaPDR4也参与了青蒿素的合成。本项目拟在前期基础上，进一步通过亚细胞定位，爪蟾卵母细胞系统和目的蛋白与底物结合等实验探究候选转运蛋白的转运底物，揭示青蒿素合成途径中代谢产物的转运机制。该项目的实施将对利用代谢工程进一步提高青蒿素含量和异源合成青蒿素前体物质具有非常重大的意义。

Artemisinin, isolated from Artemisia annua L., is widely used in the treatment of malaria. However, the artemisinin content in A. annua is relatively low. Previous studies showed that the artemisinin biosynthesis involved metabolites movement. But the mechanisms by which these molecules are transported remain poorly understood. Previously, we isolated AaPDR1, AaPDR2 and AaPDR4 from the glandular trichome transcriptome database in A. annua. These results suggested that the glandular trichome-specific transporter AaPDR1 was involved in dihydroartemisinic acid transport in artemisinin biosynthesis. AaPDR2 and AaPDR4 respectively promoted the artemisinin biosynthesis in transgenic A. annua plants. Based on these preliminary studies, we intended to verify the function of PDR transporters in A. annua and further reveal the transport mechanism in artemisinin biosynthesis via the transgenic A. annua plants analysis, xenopus oocyte expression system and the substrate binding analysis. Given the crucial role of transporters in metabolic engineering, determining to reveal the transport mechanism involved in artemisinin biosynthesisis important to improve the artemisinin yield both in planta and in yeast.