Zuo J, Niu Q W, Chua N H
Laboratory of Plant Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
Plant J. 2000 Oct;24(2):265-73. doi: 10.1046/j.1365-313x.2000.00868.x.
We have developed an estrogen receptor-based chemical-inducible system for use in transgenic plants. A chimeric transcription activator, XVE, was assembled by fusion of the DNA-binding domain of the bacterial repressor LexA (X), the acidic transactivating domain of VP16 (V) and the regulatory region of the human estrogen receptor (E; ER). The transactivating activity of the chimeric XVE factor, whose expression was controlled by the strong constitutive promoter G10-90, was strictly regulated by estrogens. In transgenic Arabidopsis and tobacco plants, estradiol-activated XVE can stimulate expression of a GFP reporter gene controlled by the target promoter, which consists of eight copies of the LexA operator fused upstream of the -46 35S minimal promoter. Upon induction by estradiol, GFP expression levels can be eightfold higher than that transcribed from a 35S promoter, whereas the uninduced controls have no detectable GFP transcripts, as monitored by Northern blot analysis. Neither toxic nor adverse physiological effects of the XVE system have been observed in transgenic Arabidopsis plants under all the conditions tested. The XVE system thus appears to be a reliable and efficient chemical-inducible system for regulating transgene expression in plants.
我们开发了一种基于雌激素受体的化学诱导系统，用于转基因植物。通过融合细菌阻遏物LexA的DNA结合结构域（X）、VP16的酸性反式激活结构域（V）和人雌激素受体的调节区域（E；ER），组装了一种嵌合转录激活因子XVE。嵌合XVE因子的表达受强组成型启动子G10 - 90控制，其反式激活活性受到雌激素的严格调控。在转基因拟南芥和烟草植株中，雌二醇激活的XVE能刺激由靶启动子控制的GFP报告基因的表达，该靶启动子由八个LexA操纵子拷贝融合在 - 46 35S最小启动子上游组成。通过Northern印迹分析监测，在雌二醇诱导后，GFP表达水平可比由35S启动子转录的水平高八倍，而未诱导的对照则没有可检测到的GFP转录本。在所有测试条件下，均未在转基因拟南芥植株中观察到XVE系统的毒性或不良生理效应。因此，XVE系统似乎是一种用于调节植物中转基因表达的可靠且高效的化学诱导系统。
