Sandhu J S, Webster C I, Gray J C
Department of Plant Sciences and Cambridge Centre for Molecular Recognition, University of Cambridge, UK.
Plant Mol Biol. 1998 Jul;37(5):885-96. doi: 10.1023/a:1006051832213.
The role of an A/T-rich positive regulatory region (P268, -444 to -177 from the translation start site) of the pea plastocyanin gene (PetE) promoter has been investigated in transgenic plants containing chimeric promoters fused to the beta-glucuronidase (GUS) reporter gene. This region enhanced GUS expression in leaves of transgenic tobacco plants when fused in either orientation to a minimal pea PetE promoter (-176 to +4) and in roots when fused in either orientation upstream or downstream of a minimal cauliflower mosaic virus 35S promoter (-90 to +5). The region was also able to enhance GUS expression in microtubers of transgenic potato plants when placed in either orientation upstream of a minimal class I patatin promoter (-332 to +14). Dissection of P268 revealed that cis elements responsible for enhancing GUS expression from the minimal PetE promoter were distributed throughout P268. Multiple copies of a 31 bp A/T-rich sequence from within P268 and of a 26 bp random A/T sequence were able to enhance GUS expression from the minimal PetE promoter, indicating that A/T-rich sequences are able to act as quantitative, non-tissue-specific enhancer elements in higher plants.
在含有与β-葡萄糖醛酸酶（GUS）报告基因融合的嵌合启动子的转基因植物中，研究了豌豆质体蓝素基因（PetE）启动子富含A/T的正调控区（P268，翻译起始位点上游-444至-177）的作用。当以任一方向与最小豌豆PetE启动子（-176至+4）融合时，该区域增强了转基因烟草植株叶片中的GUS表达；当以任一方向融合在最小花椰菜花叶病毒35S启动子（-90至+5）的上游或下游时，该区域增强了根中的GUS表达。当置于最小I类马铃薯块茎蛋白启动子（-332至+14）上游的任一方向时，该区域也能够增强转基因马铃薯植株微型块茎中的GUS表达。对P268的剖析表明，负责增强最小PetE启动子GUS表达的顺式元件分布在整个P268中。来自P268的一个31 bp富含A/T的序列和一个26 bp随机A/T序列的多个拷贝能够增强最小PetE启动子的GUS表达，表明富含A/T的序列能够作为高等植物中的定量、非组织特异性增强子元件。
