Lane Brett R, Kuhs Molly A, Zaret Max M, Song Zewei, Borer Elizabeth T, Seabloom Eric W, Schlatter Daniel C, Kinkel Linda L
Department of Plant Pathology, University of Minnesota, St. Paul, MN, United States.
Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, United States.
Front Plant Sci. 2025 Mar 5;16:1558191. doi: 10.3389/fpls.2025.1558191. eCollection 2025.
Plants in grasslands navigate a complex landscape of interactions including competition for resources and defense against pathogens. Foliar fungi can suppress plant growth directly through pathogenic interactions, or indirectly via host growth-defense tradeoffs. The exclusion of foliar fungi allows the reallocation of resources from defense to growth and reproduction. In addition, plants also invest photosynthates in rhizodeposition, or root exudates, which play a significant role in shaping the rhizosphere microbial community. However, it remains unclear what impact the exclusion of foliar fungi has on the allocation of resources to rhizodeposition and the composition of the rhizosphere microbial community. Using a 6-year foliar fungicide study in plots planted with 16 species of native prairie plants, we asked whether foliar fungi influence the rhizosphere microbial composition of a common prairie grass () and a common legume (). We found that foliar fungicide increased aboveground biomass and season-long plant production, but did not alter root biomass, seed production, or rhizosphere microbial diversity. The magnitude of change in aboveground season-long plant production was significantly associated with the magnitude of change in the rhizosphere microbial community in paired foliar fungicide-treated . control plots. These results suggest important coupling between foliar fungal infection and plant investment in rhizodeposition to modify the local soil microbial community.
草原上的植物在一个复杂的相互作用环境中生存，这些相互作用包括对资源的竞争以及对病原体的防御。叶部真菌可以通过致病相互作用直接抑制植物生长，或者通过宿主生长 - 防御权衡间接抑制。排除叶部真菌可以使资源从防御重新分配到生长和繁殖。此外，植物还会将光合产物投入到根际沉积或根系分泌物中，这对塑造根际微生物群落起着重要作用。然而，排除叶部真菌对根际沉积资源分配和根际微生物群落组成有何影响仍不清楚。通过对种植16种原生草原植物的地块进行为期6年的叶部杀菌剂研究，我们探究了叶部真菌是否会影响一种常见草原草（）和一种常见豆科植物（）的根际微生物组成。我们发现，叶部杀菌剂增加了地上生物量和整个生长季的植物产量，但没有改变根生物量、种子产量或根际微生物多样性。在配对的叶部杀菌剂处理地块和对照地块中，地上整个生长季植物产量的变化幅度与根际微生物群落的变化幅度显著相关。这些结果表明，叶部真菌感染与植物在根际沉积方面的投入之间存在重要的耦合关系，以改变当地土壤微生物群落。
