白桦糖基转移酶基因BpGT14在细胞壁发育中的功能研究

项目名称： 白桦糖基转移酶基因BpGT14在细胞壁发育中的功能研究

项目编号： No.31200463

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 林学

项目作者： 曾凡锁

作者单位： 东北林业大学

项目金额： 23万元

中文摘要： 糖基转移酶(GT)是植物细胞壁多聚糖和糖蛋白合成的关键酶。前期的转基因白桦研究获得一个茎干发育畸形、纤维素含量较低的突变体。T-DNA插入失活基因（命名BpGT14）具有植物GT14家族的保守结构域。该家族基因在细胞壁生物合成中的具体功能还不明确。以gt14突变体及转基因互补植株、BpGT14过表达植株和野生型四种基因型为材料，采用显微及亚显微结构观察和茎干机械强度测试等方法解析BpGT14在细胞壁结构、组成及茎干发育中的功能。研究该基因对细胞壁中多糖和糖蛋白合成及分布的影响,明确该糖基转移酶活性及修饰底物。筛选BpGT14上游调控蛋白及与GT14相互作用的蛋白，结合RNA原位杂交阐明该基因的表达调控模式,并解析其在组培生根过程中的作用机制。通过以上研究明确BpGT14在白桦细胞壁生物合成和组装中的功能及其对茎干和根系发育的影响，为定向改造细胞壁组成、木材特性和生物质能源定向利用奠定基础。

中文关键词： 白桦；糖基转移酶；细胞壁发育；启动子元件；

英文摘要： Glycosyltransferases (GTs) are one of the largest enzyme groups required for the synthesis of complex wall polysaccharides and glycoproteins in plants. However, due to the limited number of related mutants that have observable phenotypes, the biological function(s) of most GTs in cell-wall biosynthesis and assembly have remained elusive.We haved obtained a mutant, which show pleiotropic phenotypes, including brittleness of the plant body and retarded growth. The gt14 mutant showed impaired cellulose biosynthesis.The gene was cloned and named as BpGT14,which encodes a protein that contains high sequence similarity with glycosyltransferase 14 family. We selected the gt14 mutant and transgenic complementary plants, BpGT14 over expression plant and wild type birch as materials. Based on the stem and root cross-sectioning microscopy and submicroscopic structure and breaking force, the function of BpGT14 in cell wall structure and stem development will be analyzed. We study the effect of BpGT14 gene on the synthesis and distribution of cell wall polysaccharides and glycoproteins and reveal the glycosyltransferase activity. Screening BpGT14 upstream regulatory proteins and GT14-interacting proteins, combined with the RNA in situ hybridization, the study can clarify the expression pattern of BpGT14 gene. Based on the ab

英文关键词： Betula platypylla Suk.；BpGT14；Cell wall；Promoter elements；