Production and stabilization of antioxidant compounds in genetically modified plants introduced engineered glucosyltransferases.

多酚类化合物，如类黄酮、花青素和儿茶素，是强抗氧化剂，可以预防由活性氧和/或其他氧化剂引起的疾病。这些抗氧化多酚是植物在对抗环境胁迫时产生的，它们具有减少植物细胞氧化应激的功能。转基因植物中多酚类化合物的生产能力和稳定性提高，被认为更能抵抗氧化剂和氧化胁迫，并能在空气污染的地区生存。另一方面，将高抗氧化植物作为食物和药物资源，可以预防由氧化应激和环境氧化剂引起的人类疾病。一组花青素通常在许多植物物种中产生，并通过糖基化在植物细胞中的分子中稳定下来。此外，花青素的产生受转录因子如Myc和Myb同源蛋白的协调调节。本项目主要研究了(1)植物糖基转移酶工程重组蛋白对花青素稳定性和溶解度的影响；(2)引入Myc或Myb同源蛋白的转基因植物对花青素产率的影响。利用来自不同植物物种的葡萄糖基转移酶克隆，研究了底物特异性。在引入Myc和Myb同源物的转基因植物中，花青素的产量增加。通过酵母细胞的单/双杂交系统，研究了这些因子在体外的交互激活功能。

Polyphenol compounds such as flavonoids, athocyanins and catecins act as strong antioxidants and prevent deseases occored by active oxygen and or other oxidants. These antioxidant polyphenols are produced in plant against environmental stresses and they have functions to reduce the oxidative stresses in plant cells. Genetically modified plants in which producibility and stability of polyphenol compounds increased are supposed to be more resistant against oxidants and oxydative stresses and can survive in arear of air pollution. On the other hand, taking high-antioxidant plants as food and medicinal resources might prevent human deseases that are induced by oxidative stresses and environmental oxidants. A group of anthocyanins are commonly produced in many plant species, and stabilized by glucosylation in their molecules in plant cells. Furthermore, anthocyanin production is coordinately regulated by transcriptional factors such as Myc and Myb homologue proteins. In this project, (1)the modification of stability and solubility of anthocyanins with engineered recombinant proteins of plant glucosyltransferases and(2)the modification of anthocyanin producibility in transgenic plant introduced Myc or Myb homologue proteins were investigated. Using several clones of glucosyltransferases from different plant species, substrate specificities were investigated. In transgenic plants introduced Myc and Myb omologues, productions of anthocyanin were increased. The details of transactivational functions of these factors were studied in vitro by using one/two hybrid systems in yeast cells.