Plant microbiome research highlights the importance of indigenous microbial communities for host phenotypes such as growth and health. It aims to discover the molecular basis by which host-microbe and microbe-microbe interactions shape and maintain microbial communities and to understand the role of individual microorganisms, as well as their collective ecosystem function. Here, we discuss reductionist approaches to disentangle the inherent complexity of interactions in situ. Experimentally tractable, synthetic communities enable testing of hypotheses by targeted manipulation in gnotobiotic systems. Modifications of microbial, host, and environmental parameters allow for the quantitative assessment of host and microbe characteristics with dynamic and spatial resolution. We summarize first insights from this emerging field and discuss current challenges and limitations. Using multifaceted approaches to detect interactions and functions will provide new insights into the fundamental biology of plant-microbe interactions and help to harness the power of the microbiome.

植物微生物组研究强调了土著微生物群落对于宿主表型（例如生长和健康）的重要性。它旨在发现宿主-微生物和微生物-微生物相互作用形成和维持微生物群落的分子基础，并了解单个微生物的作用及其集体生态系统功能。在这里，我们讨论还原论方法，以解开原位相互作用的内在复杂性。在实验上易于控制的合成社区可以通过在致病菌系统中进行有针对性的操作来测试假设。微生物，宿主和环境参数的修改允许以动态和空间分辨率定量评估宿主和微生物的特征。我们总结了来自这个新兴领域的初步见解，并讨论了当前的挑战和局限性。使用多方面的方法来检测相互作用和功能将提供对植物-微生物相互作用的基本生物学的新见解，并有助于利用微生物组的力量。