Abstract:
Viral promoters can be used to drive heterologous gene expression in transgenic plants. As part of our quest to look for new promoters, we have explored, for the first time, the promoters of okra enation leaf curl virus (OELCuV), a begomovirus infecting okra (Abelmoschus esculentus). The Rep and CP promoters of OELCuV fused with the gfp reporter gene, were expressed transiently in the natural host okra and the laboratory host cotton and Nicotiana benthamiana. The expression levels of the promoters were quantified through confocal laser scanning microscopy and GFP assay in N. benthamiana and okra. The results indicated that the Rep promoter was more active than the CP promoter, whose activity was similar to that of CaMV 35S promoter. Additionally, the Rep and CP promoters showed increase of expression, probably due to transactivation, when assayed following inoculation of OELCuV and betasatellite DNAs in cotton plants. A moderate increase in promoter activity in N. benthamiana was also seen, when assayed following the inoculation of the heterologous begomovirus Sri Lankan cassava mosaic virus.
摘要:
病毒启动子可用于驱动转基因植物中的异源基因表达。作为我们寻找新推动者的一部分,我们探索过,第一次,秋葵成叶卷曲病毒(OELCuV)的启动子,感染秋葵(Abelmoschusesculentus)的双生病毒。OELCuV的Rep和CP启动子与gfp报告基因融合,在天然寄主秋葵和实验室寄主棉花和烟草中短暂表达。通过共聚焦激光扫描显微镜和GFP测定在N.benthamiana和秋葵中定量启动子的表达水平。结果表明Rep启动子的活性高于CP启动子,其活性与CaMV35S启动子相似。此外,Rep和CP启动子显示表达增加,可能是由于反式激活,在棉花植物中接种OELCuV和β卫星DNA后进行测定。还观察到N.benthamiana的启动子活性适度增加,在接种异源双生病毒斯里兰卡木薯花叶病毒后进行测定。