Laxa Miriam
Institute of Botany, Leibniz University Hannover Hannover, Germany.
Front Plant Sci. 2017 Jan 6;7:1977. doi: 10.3389/fpls.2016.01977. eCollection 2016.
Many plant promoters were characterized and used for transgene expression in plants. Even though these promoters drive high levels of transgene expression in plants, the expression patterns are rarely constitutive but restricted to some tissues and developmental stages. In terms of crop improvement not only the enhancement of expression but, in particular, tissue-specific and spatial expression of genes plays an important role. Introns were used to boost expression in transgenic plants in the field of crop improvement for a long time. However, the mechanism behind this so called intron-mediated enhancement (IME) is still largely unknown. This review highlights the complexity of IME on the levels of its regulation and modes of action and gives an overview on IME methodology, examples in fundamental research and models of proposed mechanisms. In addition, the application of IME in heterologous gene expression is discussed.
许多植物启动子已被表征并用于植物中的转基因表达。尽管这些启动子在植物中驱动高水平的转基因表达，但其表达模式很少是组成型的，而是局限于某些组织和发育阶段。就作物改良而言，不仅表达的增强，特别是基因的组织特异性和空间表达起着重要作用。在作物改良领域，内含子长期以来被用于提高转基因植物中的表达。然而，这种所谓的内含子介导增强（IME）背后的机制在很大程度上仍然未知。本综述强调了IME在其调控水平和作用模式方面的复杂性，并概述了IME方法、基础研究中的实例以及提出的机制模型。此外，还讨论了IME在异源基因表达中的应用。
