摘要： NSTs在细胞中负责将核苷酸单糖转运到高尔基体（Golgi）/内质网（ER）中，为细胞壁多糖分子的生物合成提供底物，水稻NSTs基因的研究将为深入了解植物NSTs蛋白的功能奠定良好基础。通过拟南芥AtURGT基因序列的同源比对，在水稻中发现了一个可能具有转运UDP-鼠李糖/UDP-半乳糖活性的基因，命名为OsURGT1（UDP-_L-Rha/UDP-_D-Gal transporters）。对其编码蛋白进行了氨基酸组成、进化关系、理化性质、跨膜结构域和高级结构的预测，对其启动子序列进行了顺式作用元件分析，同时还检测并分析了OsURGT1基因在水稻中的组织转录表达谱、激素及非生物胁迫处理诱导表达谱。结果显示：OsURGT1基因全长为3 421 bp，含有5个外显子；CDS全长为996 bp，编码331个氨基酸长度的蛋白，此蛋白被预测是一个疏水性蛋白，含有9个跨膜结构域；蛋白高级结构建模结果表明，其与一个NST模板蛋白高度相似。基因启动子顺式作用元件分析结果表明，OsURGT1基因有可能参与多种激素调控途径和逆境胁迫调控途径。转录表达谱分析结果表明，OsURGT1基因在水稻整个生长发育时期和各个组织部位都有表达，在叶中的表达量相对最高；对6种激素（ABA、Eth、GA、SA、MeJA、2，4-D）处理皆有较强的响应表达；对干旱、低温、盐、氧化、高温、重金属等逆境胁迫也有不同程度的响应表达。综上可知，OsURGT1基因编码一个NST蛋白家族成员，并可能参与部分激素调控和逆境胁迫响应过程。

关键词: 水稻, TPT/NST家族, 核苷酸单糖, 生物信息学分析, 逆境胁迫, 表达谱分析

Abstract: NSTs are responsible for the transport of nucleotide sugars to the Golgi/ER in cells,which provides substrates for the biosynthesis of cell wall polysaccharide molecules. The research of rice NSTs genes will lay the foundation for the further understanding of the functions of plant NSTs proteins. A gene that might transport UDP-rhamnose/UDP-galactose in rice was detected and named OsURGT1. The composition of amino acid residues,phylogenetic tree,physicochemical properties,transmembrane domain and advanced structure of the protein encoded by OsURGT1 gene were predicted,and cis-acting elements of its promoter sequence was analyzed;The expression profiles of OsURGT1 gene in different rice tissues and in rice treated by hormones and abiotic stresses were detected. The results displayed that the full length genome sequence of OsURGT1 gene was 3 421 bp,this gene contained five exons,the full length coding sequence was 996 bp,encoding 331 amino acids.This protein was predicted to be a hydrophobic protein with 9 transmembrane domains. The advanced structure prediction results of OsURGT1 protein showed that it was highly similar to an template protein of NST. The cis-acting element analysis results of the promoter indicated that OsURGT1 gene might involved in multiple hormonal regulation pathways and stress responses. The expression profile results showed that OsURGT1 gene was expressed in the whole developmental stages and in all the tissues of rice with a relatively higher expression level in leaves;the expression level of this gene was strongly induced by the treatment of six hormones (ABA,Eth,GA,SA,MeJA,2,4-D);the treatments of drought,low temperature,salt,oxidation,high temperature,heavy metal also could induce the expression of OsURGT1 gene at different degrees. Comprehensively,the OsURGT1 gene encodes a member of NST protein family and maybe involved in multiple hormone regulation and stress response processes.

Key words: Rice, TPT/NST family, Nucleotide sugar, Bioinformatics analysis, Adversity stress, Expression profile analysis

中图分类号: 

• Q751

• S511.03