Department of Biochemistry, University of Johannesburg, Auckland Park, South Africa.
Adv Exp Med Biol. 2012;738:79-107. doi: 10.1007/978-1-4614-1680-7_6.
The ability to distinguish' self' from 'nonself' is the most fundamental aspect of any immune system. The evolutionary solution in plants to the problems of perceiving and responding to pathogens involves surveillance of nonself, damaged-self and altered-self as danger signals. This is reflected in basal resistance or nonhost resistance, which is the innate immune response that protects plants against the majority of pathogens. In the case of surveillance of nonself, plants utilize receptor-like proteins or -kinases (RLP/Ks) as pattern recognition receptors (PRRs), which can detect conserved pathogen/microbe-associated molecular pattern (P/MAMP) molecules. P/MAMP detection serves as an early warning system for the presence of a wide range of potential pathogens and the timely activation of plant defense mechanisms. However, adapted microbes express a suite of effector proteins that often interfere or act as suppressors of these defenses. In response, plants have evolved a second line of defense that includes intracellular nucleotide binding leucine-rich repeat (NB-LR)-containing resistance proteins, which recognize isolate-specific pathogen effectors once the cell wall has been compromised. This host-immunity acts within the species level and is controlled by polymorphic host genes, where resistance protein-mediated activation of defense is based on an 'altered-self' recognition mechanism.
区分“自我”和“非我”是任何免疫系统最基本的方面。植物在感知和应对病原体方面的进化解决方案涉及到对非我、受损自我和改变自我的监视，将其视为危险信号。这反映在基础抗性或非寄主抗性中，即先天免疫反应，它保护植物免受大多数病原体的侵害。在非我监视的情况下，植物利用类受体蛋白或激酶（RLP/Ks）作为模式识别受体（PRRs），可以检测到保守的病原体/微生物相关分子模式（P/MAMP）分子。P/MAMP 的检测充当了广泛潜在病原体存在的早期预警系统，并及时激活植物防御机制。然而，适应的微生物表达了一系列效应蛋白，这些蛋白通常会干扰或充当这些防御的抑制剂。作为回应，植物进化出了第二道防线，包括细胞内核苷酸结合富含亮氨酸重复（NB-LR）的抗性蛋白，一旦细胞壁受到损害，这些蛋白就可以识别特定病原体的效应蛋白。这种宿主免疫作用于种内水平，由多态性宿主基因控制，其中抗性蛋白介导的防御激活基于“改变自我”的识别机制。
