参与水稻光合作用的PsbR3基因启动子的功能分析

本实验旨在研究水稻光合作用蛋白中各基因的表达模式. 采用RT-PCR和定量real-time PCR数据分析水稻不同组织的mRNA表达水平.结果显示，PsaK和PsbR3基因仅在茎、叶等绿色组织表达，而胚、胚乳部分均不表达.通过其启动子克隆、植物表达载体构建，以及农杆菌介导转化后，GUS组织染化分析和GUS荧光定量分析表明,两启动子均为组织特异性优势表达，PsbR3启动报告酶GUS在叶片中的表达活性为Actin启动子的3.29倍，而PsaK启动报告酶GUS在叶片中的表达活性低于Actin启动子的.这些初步结果提示,PsbR3启动子决定水稻绿色组织茎叶的优势表达，PsbR3基因可能参与水稻光合作用.

Characterization of PsbR3 Promoter of Rice in Photosynthesis

Promoter often determines the tissue specificity of gene expression in both plants and animals. In this study, we demonstrated that the PsbR3 promoter defined the specific gene expression in rice green tissues. The expression profiles of genes responsible for photosynthesis in different tissues of rice were analyzed by RT- PCR and quantitative real-time PCR (qRT-PCR). The results showed that PsaK and PsbR3 genes were highly expressed in green tissues such as leaf and stem but not in embryo or endosperm. To analyze the tissue specificity of the two gene promoters, GUS reporter driven by the Psak and PsbR3 promoters were constructed and used for transfection. Both histochemical staining and quantitative analysis of GUS activity showed that the two promoters appeared to be tissues specific. The Gus activity driven by the PsbR′ promoter was 3.3 folds compared to the empty vector (control); while the GUS activity driven by PsaK was lower than the control. These results suggested that PsbR3 promoter contributed to the specific expression in rice green tissues; and PsbR3 gene might associate photosynthesis.