水稻RSSG8基因启动子与GUS融合基因的构建及在烟草中的瞬间表达

使用染色体步移(Genome walking)法，从籼稻(Oryza sativa subsp．indica)桂朝2号基因组中克隆到长度为471bp的水稻精细胞优势表达基因RSSG8的启动子片段R8PN，并进行了全序列测定和分析．该段序列中含有3个CAAT-box，6个Gobox和多种植物顺式作用元件，但没有发现典型的TATA-box，推测为一种特殊的启动子结构，为了鉴定RSSG8基因的基本启动子元件，将二条长度不同的5’端侧翼区缺失体(分别长471bp，260bp)定向插入载体pBI121中，取代原有的CaMV 35S启动子，构了驱动报告基因GUS的植物表达载体pRGUS1，pRGUS2，通过农杆菌介导的瞬时表达法转化烟草叶片和花粉，快速鉴定启动子片段中起关键作用的区域，结果显示两个缺失片段都能启动GUS的表达，可以初步判定这两个片段具有启动子功能。

Construction and Transient Expression of Chimeric Genes Consisting of the Promoter of Rice RSSG8 Gene and GUS Gene in Tobacco

The promoter of RSSG8 gene in rice was cloned through twice genome walking and it was fully sequenced and analyzed. This sequence named R8PN includes three CAAT-box, six G-box and several cis-acting regulatory element, but no classical TATA-box, and is conjectured as a novel promoter. In order to identify the key functional regions of the promoter, the authors insert R8PN's two absence sequences into another vector pBI121 to take place of CaMV 35S promoter to get two expression vectors pRGUS1 and pRGUS2. By transient expressing in the leaves and pollens of tobacco transformated by Agrobecterium tumefaciens, the key functional regions of the promoter was rapidly identified. Results indicate that both the two absent segments can promote the expression of GUS gene. According to the results, the authors consider the two segments acting as promoter.