Laine Anna-Liisa
Metapopulation Research Group, Department of Biosciences, University of Helsinki Finland ; Department of Biology, University of Turku Turku, Finland.
Evol Appl. 2011 Sep;4(5):696-707. doi: 10.1111/j.1752-4571.2011.00194.x. Epub 2011 Jun 24.
The ability of a parasite strain to establish and grow on its host may be drastically altered by simultaneous infection by other parasite strains, and dynamics under multiple infection have been suggested to be a major force driving pathogen evolution. Here, I studied whether hosts' induced defenses mediate dynamics of multiple infection of the fungal pathogen, Podosphaera plantaginis, infecting Plantago lanceolata. A laboratory study of sequential infections, where interaction between pathogen strains was prevented, showed that ability to establish remained unaffected, but prior infection elevates the host's resistance to the degree that subsequent infection development is significantly reduced. However, when inoculated plants and their healthy controls were planted back into their natural populations, hosts with prior infection became more heavily infected by the subsequent infections than the initially healthy plants. Hence, a controlled short-term laboratory study is a poor predictor of the host's ability to mediate multiple infection during the course of natural epidemics. These results have applied implications for priming where the plants' defenses are elicited to provide protection against further attack, highlighting the importance of testing priming under natural conditions for relevant time scales.
一种寄生虫菌株在其宿主上定殖和生长的能力可能会因同时感染其他寄生虫菌株而发生巨大改变，并且有人认为多重感染下的动态变化是推动病原体进化的主要力量。在此，我研究了宿主的诱导防御是否介导了真菌病原体车前白粉菌（Podosphaera plantaginis）对披针叶车前（Plantago lanceolata）的多重感染动态。一项对顺序感染的实验室研究，其中病原体菌株之间的相互作用被阻止，结果表明定殖能力不受影响，但先前的感染会提高宿主的抗性，以至于随后的感染发展会显著减少。然而，当将接种过的植物及其健康对照重新种植到它们的自然种群中时，先前感染过的宿主比最初健康的植物更容易受到随后感染的严重感染。因此，一项受控的短期实验室研究并不能很好地预测宿主在自然流行过程中介导多重感染的能力。这些结果对引发作用具有实际意义，在引发作用中，植物的防御被激发以提供针对进一步攻击的保护，突出了在自然条件下针对相关时间尺度测试引发作用的重要性。
