Sacristán Soledad, García-Arenal Fernando
Depto. de Biotecnología, E.T.S.I. Agrónomos and Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Mol Plant Pathol. 2008 May;9(3):369-84. doi: 10.1111/j.1364-3703.2007.00460.x.
The term virulence has a conflicting history among plant pathologists. Here we define virulence as the degree of damage caused to a host by parasite infection, assumed to be negatively correlated with host fitness, and pathogenicity the qualitative capacity of a parasite to infect and cause disease on a host. Selection may act on both virulence and pathogenicity, and their change in parasite populations can drive parasite evolution and host-parasite co-evolution. Extensive theoretical analyses of the factors that shape the evolution of pathogenicity and virulence have been reported in last three decades. Experimental work has not followed the path of theoretical analyses. Plant pathologists have shown greater interest in pathogenicity than in virulence, and our understanding of the molecular basis of pathogenicity has increased enormously. However, little is known regarding the molecular basis of virulence. It has been proposed that the mechanisms of recognition of parasites by hosts will have consequences for the evolution of pathogenicity, but much experimental work is still needed to test these hypotheses. Much theoretical work has been based on evidence from cellular plant pathogens. We review here the current experimental and observational evidence on which to test theoretical hypotheses or conjectures. We compare evidence from viruses and cellular pathogens, mostly fungi and oomycetes, which differ widely in genomic complexity and in parasitism. Data on the evolution of pathogenicity and virulence from viruses and fungi show important differences, and their comparison is necessary to establish the generality of hypotheses on pathogenicity and virulence evolution.
在植物病理学家中，“毒力”一词有着相互矛盾的历史。在这里，我们将毒力定义为寄生虫感染对宿主造成的损害程度，假定其与宿主适应性呈负相关，而致病性则是指寄生虫感染宿主并引发疾病的定性能力。选择可能作用于毒力和致病性，它们在寄生虫种群中的变化会推动寄生虫进化以及宿主 - 寄生虫的共同进化。在过去三十年中，已经报道了对影响致病性和毒力进化的因素进行的广泛理论分析。实验工作并未遵循理论分析的路径。植物病理学家对致病性的兴趣大于对毒力的兴趣，并且我们对致病性分子基础的理解有了极大的提高。然而，关于毒力的分子基础却知之甚少。有人提出宿主对寄生虫的识别机制将对致病性的进化产生影响，但仍需要大量实验工作来检验这些假设。许多理论工作是基于细胞植物病原体的证据。我们在此回顾当前用于检验理论假设或推测的实验和观察证据。我们比较来自病毒和细胞病原体（主要是真菌和卵菌）的证据，它们在基因组复杂性和寄生方式上有很大差异。来自病毒和真菌的致病性和毒力进化数据显示出重要差异，对它们进行比较对于确定关于致病性和毒力进化假设的普遍性是必要的。
