Adaptation to specialized environments allows microorganisms to inhabit an enormous variety of ecological niches. Growth inside plant tissues is a niche offering a constant nutrient supply, but to access this niche, plant defense mechanisms ranging from passive barriers to induced defense reactions have to be overcome. Pathogens have to break several, if not all, of these barriers. For this purpose, they secrete effector molecules into plant cells to interfere with individual defense responses. Plant defense is organized in multiple layers, and therefore the action of effectors likely follows this same order, leading to a hierarchy in effector orchestration. In this review we summarize the latest findings regarding the level at which effectors manipulate plant immunity. Particular attention is given to those effectors whose mechanism of action is known. Additionally, we compare methods to identify and characterize effector molecules.

中文翻译：

---

突破壁垒：微生物效应分子破坏了植物的免疫力。

适应特殊环境可使微生物栖息于各种各样的生态位中。植物组织内部的生长是提供恒定营养供应的生态位，但是要进入该生态位，必须克服从被动屏障到诱导防御反应等多种植物防御机制。病原体必须打破这些障碍中的几个（即使不是全部）障碍。为此，它们将效应分子分泌到植物细胞中以干扰个体防御反应。植物防御是多层组织的，因此效应器的动作可能遵循相同的顺序，从而导致效应器编排中的层次结构。在这篇综述中，我们总结了关于效应子操纵植物免疫力水平的最新发现。特别注意那些作用机理已知的效应子。此外，我们比较了鉴定和表征效应分子的方法。