次生代谢产物转运和代谢工程是植物科学研究热点之一。托品烷生物碱(TAs) 如莨菪碱，其生物合成途径及代谢工程研究较深入。但关于TAs转运的分子机理不清楚，基于TAs转运的代谢工程研究未见报道。托品酮还原反应是TAs合成途径中的分支点，包括生成托品(参与TAs合成)和假托品(参与打碗花精类生物碱合成)，对该分支点的代谢工程研究有待深入。综合调控代谢物转运和合成途径的TAs代谢工程研究未见报道。.本课题将从TAs商业药源植物颠茄中鉴定莨菪碱转运蛋白，解析其生物学功能，阐明莨菪碱转运分子机理；鉴定TAs合成途径的托品酮还原酶I(TRI)和竞争途径的托品酮还原酶II(TRII)，阐明其生化功能，为针对托品酮还原反应的TAs代谢工程提供理论依据。最终基于本课题鉴定的基因，采用综合调控“转运蛋白-合成途径关键酶-竞争途径关键酶”基因的方法建立新型的TAs代谢工程策略，并培育出TAs高产转基因颠茄。

Metabolite transportation and metabolic engineering are the hot spots of the plant science field. Biosynthesis of tropane alkaloids (TAs), such as hyoscyamine, has been intensively studied at the molecular and biochemical levels, and further metabolic engineering of TAs biosynthesis has made great progress. Unfortunately, the molecular mechnism on TAs transportation is still unknown and engineering TAs transportation is impossible without the knowkedge of TAs transporters. In the TAs biosynthetic pathway, tropinone reduction is the branch point. Tropinone reductase I (TRI) reduces tropinone to tropine that participates pharmaceutical TAs biosynthesis; tropinone reductase II reduces tropinone to pseudotropine that participates calystegin biosynthesis. These suggest that TRII might compete for the substrate tropinone with TRII. However, the effect of suppressing TRII on TAs biosynthesis is unclear. There is no report on improving TAs production by regulating TAs transportion and biosynthesis together..In this project, Atropa belladonna, the most commercially important plant for TAs production, is used as material. Hyoscyamine specific transporters will be functionally identified to understand how hyoscyamine is transported in planta and estimate their values in transport engineering. TRI and TRII of A. belladonna will be functionally identified and their roles in engineering of TAs production will be revealed. Finally, based on the genes discovered in this project, we will established a novel TAs metabolic engineering strategy through comprehensively regulating transporters-key enzymes involved in target metabolite biosynthesis-key enzymes competing for target metabolite biosynthesis. As a result of these research, the new varieties of A. belladonna with high-yield TAs will be developed.