3-磷酸甘油醛和丙酮酸是萜类化合物MEP通用合成途径的关键前体。如何实现这两个代谢物的平衡供给是萜类化合物高效合成的关键。3-磷酸甘油醛和丙酮酸是糖酵解中央代谢途径的代谢物。由于3-磷酸甘油醛会被持续不断地转化为丙酮酸，因此传统糖酵解途径很难实现3-磷酸甘油醛和丙酮酸的平衡供给。本项目拟以甘油为碳源，引入甘油新代谢途径提供丙酮酸，通过甘油传统代谢途径提供3-磷酸甘油醛并阻断其和丙酮酸之间的偶联。在此基础上，鉴定新旧两条甘油代谢途径的限速步骤，并用基因组编辑技术对这两条途径中的限速酶基因进行同时调控，筛选出最利于萜类化合物合成的组合。最后，基于碳代谢流和代谢中间物浓度分析，解析3-磷酸甘油醛和丙酮酸的比例及碳代谢流分布和萜类化合物合成之间的相互关系。本项目创建的3-磷酸甘油醛和丙酮酸平衡供给的新型人工调控策略有助于解析这两个关键前体对萜类化合物合成的调控机制。

Glyceraldehyde 3-phosphate (G3P) and pyruvate are two key precursors of MEP pathway, which is the common synthetic pathway of terpenoids compounds. Balanced supply of G3P and pyruvate is very important to obtain an efficient terpenoids synthetic pathway. These two precursors are metabolites of the central glycolysis pathway. Because G3P is continuously converted to pyruvate, it is very difficult to obtain balanced supply of these two precursors using traditional glycolysis pathway. In this project, glycerol is used as the carbon source and a novel glycerol metabolic pathway will be created for pyruvate supply. Traditional glycerol metabolic pathway will be used for G3P supply, and the connection between G3P and pyruvate will be disrupted. Rate limiting steps of these two glycerol metabolic pathways will be identified, and genome editing technologies will be used to modulate expression of these rate limiting genes. The best combination for terpenoids synthesis will be identified. In addition, carbon flux analysis will be performed, as well as measurement of key metabolites concentrations. The relationship between the ratio of G3P and pyruvate, carbon flux distribution and terpenoids synthesis will be identified. The new artificial regulation strategy will facilitate characterization of the regulating mechanism of G3P and pyruvate for terpenoids synthesis.