Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Nat Plants. 2023 Aug;9(8):1184-1190. doi: 10.1038/s41477-023-01466-1. Epub 2023 Aug 3.
Plant nucleotide-binding leucine-rich repeat receptors (NLRs) are intracellular immune receptors that are activated by their direct or indirect interactions with virulence effectors. NLR activation triggers a strong immune response and consequent disease resistance. However, the NLR-driven immune response can be targeted by virulence effectors. It is thus unclear how immune activation can occur concomitantly with virulence effector suppression of immunity. Recent observations suggest that the activation of effector-triggered immunity does not sustain defence gene expression in tissues in contact with the hemi-biotrophic pathogen Pseudomonas syringae pv. tomato. Instead, strong defence was observed on the border of the infection area. This response is reminiscent of localized acquired resistance (LAR). LAR is a strong defence response occurring in a ~2 mm area around cells in contact with the pathogen and probably serves to prevent the spread of pathogens. Here we propose that effector-triggered immunity is essentially a quarantining mechanism to prevent systemic pathogen spread and disease, and that the induction of LAR is a key component of this mechanism.
植物核苷酸结合富含亮氨酸重复受体 (NLR) 是细胞内免疫受体，通过与毒力效应因子的直接或间接相互作用而被激活。NLR 的激活引发强烈的免疫反应和随后的疾病抗性。然而，NLR 驱动的免疫反应可能会被毒力效应因子靶向。因此，尚不清楚免疫激活如何能够与毒力效应因子抑制免疫同时发生。最近的观察表明，效应子触发的免疫激活不会维持与半生物营养性病原体丁香假单胞菌 pv.番茄接触的组织中的防御基因表达。相反，在感染区域的边界观察到强烈的防御。这种反应使人联想到局部获得性抗性 (LAR)。LAR 是一种强烈的防御反应，发生在与病原体接触的细胞周围约 2mm 的区域，可能有助于防止病原体的传播。在这里，我们提出效应子触发的免疫本质上是一种隔离机制，以防止系统性的病原体传播和疾病，而 LAR 的诱导是该机制的关键组成部分。
