VB6包括6个吡啶衍生物。植物合成的VB6对植物自身的生长发育和逆境适应，以及人和动物营养具有重要意义。目前，植物VB6的从头合成途径已经明确，合成后的代谢转换更加重要，但还知之甚少。我们成功解析了植物（烟草）体内VB6的代谢转换，获得了重要调控信息和研究线索，提出了代谢转换的调控假说并克隆出代谢酶基因。本项目继续使用烟草，以PLP磷酸酶、PL还原酶和PM-丙酮酸转氨酶为焦点，采用基因操作技术构建实验模型，在酶作用分子水平上明确VB6代谢转换的平衡位点、PLP和PL水平的调控机制、PL和PM相互转换的生理意义等重要问题；结合转录组和蛋白组学分析，获取涉及VB6代谢转换的基因调控网络重要信息；通过降解产物和作用酶的鉴定，探索VB6的降解问题。本项目为原创性和前沿性研究，为阐明植物体内VB6作用机理的理论研究奠定基础，为提高食源性植物的VB6含量和增强植物逆境适应能力的应用研究提供理论依据。

VB6 consists of six interconvertible pyridine compounds including PN, PM, PL and their phosphorylated derivatives, PNP, PMP and PLP. As an important secondary metabolite, VB6 plays a crucial role in plant growth and development, acts as efficient antioxidants to increase tolerance to biotic and abiotic stresses, and is an important nutrition for human and animals. At present, the de novo synthesis pathway of VB6 in plants has been clear, and the metabolic conversion of VB6 after de novo synthesis is more important, but still a lot of unknown. Tobacco, an important model and economic plant, its VB6 biosynthetic pathway was first illuminated. We have successfully revealed the metabolic conversion of VB6 in tobacco, obtained important information and clues for further study, put forward the regulation hypothesis about VB6 metabolic conversion and cloned the genes of metabolic enzymes. In this project, we intend to use tobacco continually, focus on the PLP phosphatase, PL reductase and PM-pyruvate transaminase, establish the experimental model by genetic manipulation techniques, further reveal the balance site and the regulatory mechanism of VB6 metabolic conversion at the molecular level of enzyme action, including the regulation of PLP and PL levels, the physiological significance of PL and PM conversion, such important issues. The project also identify the important information about the genetic regulatory network involving VB6 metabolic conversions by combining transcriptomic and proteomic analysis, and explore the degradation of VB6 by identifying the degradation products and the action enzymes. This project is an original and cutting-edge research, and aims to lay a foundation for the theoretical research on the mechanism of VB6 action in plants, provide the theoretical basis for the application research to improve the VB6 content in food plant, and enhance the ability of plants to adapt adversity by utilizing VB6 special physiological functions.