紫薯糖基化修饰酶Ib3GGT对花青素修饰和富集的研究

项目名称： 紫薯糖基化修饰酶Ib3GGT对花青素修饰和富集的研究

项目编号： No.31501357

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 食品科学、农学基础与作物学

项目作者： 王红霞

作者单位： 中国科学院上海生命科学研究院

项目金额： 20万元

中文摘要： 花青素糖基化修饰影响花青素在细胞中的稳定性。不同于拟南芥，紫薯以花青素-3-O-葡糖苷进一步糖基化形成花青素-3-O-葡糖苷-2”-O-葡糖苷(又称花青素-3-O-槐糖苷)为基础衍生出花青素的不同组分，解析催化该步骤的糖基转移酶Ib3GGT的生物学功能，可深入了解该酶对紫薯花青素糖基化修饰、转运及富集的影响。前期实验表明Ib3GGT可催化花青素-3-O-葡糖苷形成花青素-3-O-槐糖苷，且其定位在内质网及高尔基体中表明该酶是在花青素转运到液泡前进行糖基化修饰的。干扰及过表达Ib3GGT的转基因紫薯幼叶花青素自发荧光实验表明该酶影响到花青素在液泡中的富集程度。下一步将开展酵母双杂等实验寻找Ib3GGT与花青素转运及富集有关的互作蛋白、酵母中该酶功能的验证和转基因植株的分析等。本研究旨在阐明紫薯花青素进一步糖基化修饰与花青素转运及富集的联系，为解析花青素的富集机制及作物花青素改良提供理论依据。

中文关键词： 紫薯；花青素富集；；花青素-3-O-葡糖苷糖基转移酶；基因功能；遗传改良

英文摘要： The glycosylation of anthocyanidin influences anthocyanins stability in plant cells and is a key process leading to compound diversity and function. In contrast to Arabidopsis, purple sweet potato anthocyanidin 3-O-glucosides can be further modified to yield anthocyanidin 3-O-glucoside-2’’-O-glucoside (i.e. anthocyanidin 3-O-sophorosides) by the enzyme UDP-glucose:anthocyanidin 3- O- glucoside-2”- O- glucosyltransferase (3GGT). The aim of this study is to explore biological functions of purple sweet potato Ib3GGT on glycosylation, transport and compounds diversity of anthocyanins. Our previous study demonstrated that Ib3GGT was localized in endoplasmic reticulum and golgi apparatus and catalyzed the substrate anthocyanidin 3-O-glucosides into anthocyanidin 3-O-sophorosides. Thus, anthocyanin was modified by Ib3GGT before transported and accumulated in vacuole. Detection of anthocyanin autofluorescence in young leaf of RNAi and overexpression Ib3GGT transgenic plant revealed that anthocyanin accumulation in vacuole was affected of Ib3GGT level. In future study, we will look for the interaction proteins of Ib3GGT through yeast-two-hybrid and co-imunoprecipitation methods. Our objective is to elucidate the biological function of Ib3GGT in further anthocyanidin glycosylation. This work can provide the fundamental knowledge and new approaches for anthocyanin improvement in crops.

英文关键词： purple sweetpotato;anthocyanin accumulation; Anthocyanidin-3-O-glucoside glucosyltransferase;gene function ;genetic improvement