Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands.
Department of Soil Quality, Wageningen University, 6708 PB, Wageningen, The Netherlands.
ISME J. 2018 May;12(5):1252-1262. doi: 10.1038/s41396-017-0035-3. Epub 2018 Jan 22.
Plants release a wide set of secondary metabolites including volatile organic compounds (VOCs). Many of those compounds are considered to function as defense against herbivory, pests, and pathogens. However, little knowledge exists about the role of belowground plant VOCs for attracting beneficial soil microorganisms. We developed an olfactometer system to test the attraction of soil bacteria by VOCs emitted by Carex arenaria roots. Moreover, we tested whether infection of C. arenaria with the fungal pathogen Fusarium culmorum modifies the VOCs profile and bacterial attraction. The results revealed that migration of distant bacteria in soil towards roots can be stimulated by plant VOCs. Upon fungal infection, the blend of root VOCs changed and specific bacteria with antifungal properties were attracted. Tests with various pure VOCs indicated that those compounds can diffuse over long distance but with different diffusion abilities. Overall, this work highlights the importance of plant VOCs in belowground long-distance plant-microbe interactions.
植物会释放出一系列次生代谢物，包括挥发性有机化合物（VOCs）。其中许多化合物被认为具有防御食草动物、害虫和病原体的功能。然而，对于地下植物 VOCs 吸引有益土壤微生物的作用知之甚少。我们开发了一种嗅觉仪系统来测试由 Carex arenaria 根系释放的 VOCs 对土壤细菌的吸引力。此外，我们还测试了 C. arenaria 被真菌病原体 Fusarium culmorum 感染是否会改变 VOCs 特征和细菌吸引力。结果表明，土壤中远距离细菌向根系的迁移可以被植物 VOCs 所刺激。在真菌感染后，根系 VOCs 的混合物发生了变化，并且具有抗真菌特性的特定细菌被吸引。使用各种纯 VOCs 的测试表明，这些化合物可以长距离扩散，但扩散能力不同。总的来说，这项工作强调了植物 VOCs 在地下长距离植物-微生物相互作用中的重要性。
