Lang Zhihong, Zhou Peng, Yu Jingjuan, Ao Guangming, Zhao Qian
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100094, People's Republic of China.
Planta. 2008 Jan;227(2):387-96. doi: 10.1007/s00425-007-0625-9. Epub 2007 Sep 26.
SBgLR (Solanum tuberosum genomic lysine-rich) gene was isolated from a potato genomic library using SB401 (S. berthaultii 401) cDNA as probe. RT-PCR analysis of SBgLR gene expression profile and microscopic analysis of green fluorescent protein (GFP) expression in tobacco plants transformed with SBgLR promoter-GFP reporters indicate that SBgLR is a pollen-specific gene. A series of 5'deletions of SBgLR promoter were fused to the beta-glucuronidase (GUS) gene and stably introduced into tobacco plants. Histochemical and quantitative assays of GUS expression in transgenic plants allowed us to localize an enhancer of SBgLR promoter to the region -345 to -269 relative to the translation start site. This 76 bp (-345 to -269) fragment enhanced GUS expression in leaves, stems and roots when fused to -90/+6 CaMV 35S minimal promoter. Deletion analysis showed that a cis-element, which can repress gene expression in root hairs, was located in the region -345 to -311. Further study indicated that the -269 to -9 region was sufficient to confer pollen-specific expression of GFP when fused to CaMV 35S enhancer.
利用SB401（伯氏马铃薯401）cDNA作为探针，从马铃薯基因组文库中分离出SBgLR（马铃薯基因组富含赖氨酸）基因。对SBgLR基因表达谱进行逆转录聚合酶链反应（RT-PCR）分析，并用SBgLR启动子-绿色荧光蛋白（GFP）报告基因转化烟草植株，对GFP表达进行显微镜分析，结果表明SBgLR是一个花粉特异性基因。将一系列SBgLR启动子的5'端缺失片段与β-葡萄糖醛酸酶（GUS）基因融合，并稳定导入烟草植株。通过对转基因植株中GUS表达进行组织化学和定量分析，我们将SBgLR启动子的一个增强子定位到相对于翻译起始位点的-345至-269区域。当该76bp（-345至-269）片段与-90/+6花椰菜花叶病毒（CaMV）35S最小启动子融合时，可增强其在叶、茎和根中的GUS表达。缺失分析表明，一个可抑制根毛中基因表达的顺式元件位于-345至-311区域。进一步研究表明，当与CaMV 35S增强子融合时，-269至-9区域足以赋予GFP花粉特异性表达。
