Rasmussen Thomas Bruun, Donaldson Iain A
Danisco Innovation, Langebrogade 1, 1001, Copenhagen K, Denmark.
Plant Cell Rep. 2006 Oct;25(10):1035-42. doi: 10.1007/s00299-006-0158-x. Epub 2006 May 3.
We report the investigation of an endosperm-specific promoter from the rsus3 gene from rice (Oryza sativa). The promoter was characterized by deletion analysis and transient expression in guar (Cyamopsis tetragonoloba) seed-tissue. Transient expression was monitored by histochemical GUS assay, and quantitative dual reporter assays comprising firefly luciferase as a test reporter, and Renilla luciferase and GUS as reference reporters. These revealed high expression levels of the reporter genes directed by the rsus3 promoter in guar endosperm. Specificity for this tissue in seeds was apparent from a virtual absence of reporter activity in guar cotyledons. Removal of a putative intron region only slightly raised the expression level, whereas duplication of the minimal promoter region, in a tandem-repeat rsus3 promoter construct, retained endosperm specificity in guar, and displayed three times the reporter activity observed with the single copy construct.
我们报告了对来自水稻（Oryza sativa）rsus3基因的胚乳特异性启动子的研究。通过缺失分析和在瓜尔豆（Cyamopsis tetragonoloba）种子组织中的瞬时表达对该启动子进行了表征。通过组织化学GUS测定以及包括萤火虫荧光素酶作为测试报告基因、海肾荧光素酶和GUS作为参考报告基因的定量双报告基因测定来监测瞬时表达。这些结果显示，rsus3启动子指导的报告基因在瓜尔豆胚乳中具有高表达水平。从瓜尔豆子叶中几乎没有报告基因活性可以明显看出该启动子对种子中该组织的特异性。去除一个推定的内含子区域仅略微提高了表达水平，而在串联重复的rsus3启动子构建体中最小启动子区域的重复，在瓜尔豆中保留了胚乳特异性，并显示出单拷贝构建体所观察到的报告基因活性的三倍。
