Sick plants in grassland communities: a growth-defense trade-off is the main driver of fungal pathogen abundance
Sick plants in grassland communities: a growth-defense trade-off is the main driver of fungal pathogen abundance
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DOI：
10.1111/ele.13537
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发表时间：
2020-05-26
期刊：
影响因子：
8.8
通讯作者：
Allan, Eric
中科院分区：
文献类型：
--
作者：
Cappelli, Seraina L.;Pichon, Noemie A.;Allan, Eric
地上真菌病原体可以大大减少草原的生物量生产。然而，我们缺乏对真菌病原体感染的驱动因素和影响的机制了解。通过草原全球变化和生物多样性实验，我们表明植物生长和防御之间的权衡是感染发生率的主要决定因素。相比之下，添加氮仅通过将植物群落转向生长更快的物种来间接增加发病率。植物多样性并没有降低发病率，可能是因为通用病原体的溢出或易感植物的优势抵消了多样性的负面影响。杀菌剂处理增加了植物生物量的产生，而高水平的感染发生率与生物量的减少有关。然而，病原体的影响取决于具体情况，并且感染发生率在不同社区中更强烈地降低了生物量。我们的结果表明，生长与防御的权衡是病原体发病的关键驱动因素，但病原体的影响是由多种机制决定的，并且可能取决于病原体群落的组成。
Aboveground fungal pathogens can substantially reduce biomass production in grasslands. However, we lack a mechanistic understanding of the drivers of fungal pathogen infection and impact. Using a grassland global change and biodiversity experiment we show that the trade-off between plant growth and defense is the main determinant of infection incidence. In contrast, nitrogen addition only indirectly increased incidence via shifting plant communities towards faster growing species. Plant diversity did not decrease incidence, likely because spillover of generalist pathogens or dominance of susceptible plants counteracted negative diversity effects. A fungicide treatment increased plant biomass production and high levels of infection incidence were associated with reduced biomass. However, pathogen impact was context dependent and infection incidence reduced biomass more strongly in diverse communities. Our results show that a growth-defense trade-off is the key driver of pathogen incidence, but pathogen impact is determined by several mechanisms and may depend on pathogen community composition.