植物的化学诱导表达系统

The Chemical-inducible Expression System of Plant Genes

利用植物内源性化学诱导启动子或其它生物的化学诱导响应元件都可以在植物中构建化学诱导表达系统。化学诱导表达系统可以分为去抑制、失活、激活三种 ,三种方式的原理相似 ,需要两个转录单位组成 ,第一个转录单位由一个组成型启动子 (如CaMV 35S)转录一个对化学诱导剂敏感的转录因子 ,第二个转录单位含有多个能结合转录因子的位点与一个基本植物启动子 (如截短的CaMV 35S)组成的嵌合型启动子调控目的基因的表达。构建双元调控系统可以克服单元系统的不足。文章叙述了一些已构建的化学诱导系统的特征和局限性 ,阐明了理想化学诱导表达系统的要求和理想化学诱导剂的条件。指出化学诱导系统的应用是很有前途的。

To establish chemical-inducible systems for regulated expression of plant genes, two different strategies are being adopted. The first strategy is using endogenous chemical-inducible promoters in plants. The second strategy involves using regulatory elements responding to chemicals from other organism that are not usually encountered by plants. Chemical-inducible expression systems in plants, in general, are based on de-repression, inactivation, and activation of transcription of the target gene. All these systems contain two transcription units, whereas the first unit employs a constitutive promoter (e.g. CaMV 35S) to express a chemical-responsive transcription factor. The second unit consists of multiple copies of the transcription factor binding site linked to a minimal plant promoter (e.g. a truncated CaMV 35S), which is used to expression the target gene. In order to overcome the drawbacks of the single-control inducible system, the dual-control inducible system was developed by combining the advantages of the two systems and eliminating most of the disadvantages. This paper described the properties of some chemical-inducible systems in plant and desired properties of an ideal chemical-inducible system and properties required for an ideal chemical inducer. The chemical-inducible system are promoter for transgene application for experimental and field use.