Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, 85764 Neuherberg, Germany.
Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, 85764 Neuherberg, Germany.
Plant Physiol. 2018 Apr;176(4):2639-2656. doi: 10.1104/pp.17.01810. Epub 2018 Feb 8.
Symbioses between plants and mycorrhizal fungi are ubiquitous in ecosystems and strengthen the plants' defense against aboveground herbivores. Here, we studied the underlying regulatory networks and biochemical mechanisms in leaves induced by ectomycorrhizae that modify herbivore interactions. Feeding damage and oviposition by the widespread poplar leaf beetle were reduced on the ectomycorrhizal hybrid poplar × Integration of transcriptomics, metabolomics, and volatile emission patterns via mass difference networks demonstrated changes in nitrogen allocation in the leaves of mycorrhizal poplars, down-regulation of phenolic pathways, and up-regulation of defensive systems, including protease inhibitors, chitinases, and aldoxime biosynthesis. Ectomycorrhizae had a systemic influence on jasmonate-related signaling transcripts. Our results suggest that ectomycorrhizae prime wounding responses and shift resources from constitutive phenol-based to specialized protective compounds. Consequently, symbiosis with ectomycorrhizal fungi enabled poplars to respond to leaf beetle feeding with a more effective arsenal of defense mechanisms compared with nonmycorrhizal poplars, thus demonstrating the importance of belowground plant-microbe associations in mitigating aboveground biotic stress.
植物与菌根真菌之间的共生关系在生态系统中普遍存在，并增强了植物对地上食草动物的防御能力。在这里，我们研究了菌根诱导的叶片中调节网络和生化机制，这些机制改变了食草动物的相互作用。广泛分布的杨树叶甲虫的取食损害和产卵在菌根杂交杨树上减少了。通过质量差异网络整合转录组学、代谢组学和挥发物排放模式表明，菌根杨树叶片中的氮分配发生变化，酚类途径下调，防御系统上调，包括蛋白酶抑制剂、几丁质酶和醛肟生物合成。菌根对茉莉酸相关信号转导转录物有系统影响。我们的研究结果表明，菌根使受伤反应提前，并将资源从组成性基于酚类的化合物转移到专门的保护化合物上。因此，与非菌根杨树相比，与菌根真菌共生使杨树能够更有效地利用防御机制来应对叶甲虫的取食，这表明地下植物-微生物的相互作用在减轻地上生物胁迫方面的重要性。
