Swiss Federal Institute of Technology (ETH-Z), Department of Biology, Universitätstrasse 2, 8092 Zurich, Switzerland.
Curr Opin Plant Biol. 2011 Oct;14(5):580-7. doi: 10.1016/j.pbi.2011.07.011. Epub 2011 Aug 19.
In plants, once triggered within a single-cell type, transgene-mediated RNA-silencing can move from cell-to-cell and over long distances through the vasculature to alter gene expression in tissues remote form the primary sites of its initiation. Although, transgenic approaches have been instrumental to genetically decipher the components and channels required for mobile silencing, the possible existence and biological significance of comparable endogenous mobile silencing pathways has remained an open question. Here, we summarize the results from recent studies that shed light on the molecular nature of the nucleic acids involved and on existing endogenous mechanisms that allow long-distance gene regulation and epigenetic modifications. We further elaborate on these and other results to propose a unified view of various non-cell autonomous RNA silencing processes that appear to differ in their genetic requirement and modes of perpetuation in plants.
在植物中，一旦在单一细胞类型中被触发，转基因介导的 RNA 沉默可以在细胞间移动，并通过脉管系统远距离传播，从而改变远离其起始主要部位的组织中的基因表达。尽管转基因方法对于遗传解析移动沉默所需的组件和通道是至关重要的，但可比的内源性移动沉默途径的可能存在和生物学意义仍然是一个悬而未决的问题。在这里，我们总结了最近的研究结果，这些结果阐明了涉及的核酸的分子性质，以及允许远距离基因调控和表观遗传修饰的现有内源性机制。我们进一步详细阐述了这些和其他结果，提出了一个统一的观点，即各种非细胞自主的 RNA 沉默过程似乎在遗传要求和在植物中的持续方式上有所不同。
