Robatzek Silke
Max-Planck-Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, 50829 Köln, Germany.
Cell Microbiol. 2007 Jan;9(1):1-8. doi: 10.1111/j.1462-5822.2006.00829.x. Epub 2006 Nov 1.
In plants, perception of pathogen-associated molecular patterns at the surface is the first line of defence in cellular immunity. This review summarizes recent evidence of the involvement of vesicle trafficking in the plant's immune response against pathogens. I first discuss aspects of ligand-stimulated receptor endocytosis. The best-characterized pattern-recognition receptor (PRR), FLS2, is a transmembrane leucine-rich repeat receptor kinase that recognizes bacterial flagellin. FLS2 was recently shown to undergo internalization upon activation with its cognate ligand. An animal PRR, TLR4 that mediates perception of bacterial-derived lipopolysaccharides, similarly exhibits ligand-stimulated endocytosis. The second focus is N-ethylmaleimide-sensitive factor adaptor protein receptor (SNARE)-mediated immunity involving syntaxins and their cognate partners. One of the genes involved in basal immunity in Arabidopsis, PEN1, encodes a syntaxin that focally accumulates at fungal penetration sites, raising the possibility that induced exocytosis is important for active defence. Pathogen-triggered endocytic and exocytic processes have to be balanced to ensure host cell homeostasis. Thus, understanding how phytopathogens have evolved strategies to exploit host cell vesicle trafficking to manipulate immune responses is currently an area of intense study.
在植物中，对病原体相关分子模式的识别是细胞免疫的第一道防线。本综述总结了囊泡运输参与植物对病原体免疫反应的最新证据。我首先讨论配体刺激的受体内吞作用的相关方面。特征最明确的模式识别受体（PRR）FLS2是一种跨膜富含亮氨酸重复序列的受体激酶，可识别细菌鞭毛蛋白。最近研究表明，FLS2在与同源配体激活后会发生内化。一种介导对细菌衍生脂多糖识别的动物PRR，即TLR4，同样表现出配体刺激的内吞作用。第二个重点是N - 乙基马来酰亚胺敏感因子衔接蛋白受体（SNARE）介导的免疫，涉及 syntaxin及其同源伴侣。拟南芥中参与基础免疫的基因之一PEN1编码一种 syntaxin，它在真菌穿透位点局部积累，这增加了诱导性胞吐作用对主动防御很重要的可能性。病原体触发的内吞和胞吐过程必须保持平衡，以确保宿主细胞的稳态。因此，了解植物病原体如何进化策略利用宿主细胞囊泡运输来操纵免疫反应，目前是一个深入研究的领域。
