The association between plants and arbuscular mycorrhizal fungi (AMF) affects plant performance and ecosystem functioning. Recent studies have identified AMF-associated bacteria as cooperative partners that participate in AMF–plant symbiosis: specific endobacteria live inside AMF, and hyphospheric bacteria colonize the soil that surrounds the extraradical hyphae. In this Review, we describe the concept of a plant–AMF–bacterium continuum, summarize current advances and provide perspectives on soil microbiology. First, we review the top-down carbon flow and the bottom-up mineral flow (especially phosphorus and nitrogen) in this continuum, as well as how AMF–bacteria interactions influence the biogeochemical cycling of nutrients (for example, carbon, phosphorus and nitrogen). Second, we discuss how AMF interact with hyphospheric bacteria or endobacteria to regulate nutrient exchange between plants and AMF, and the possible molecular mechanisms that underpin this continuum. Finally, we explore future prospects for studies on the hyphosphere to facilitate the utilization of AMF and hyphospheric bacteria in sustainable agriculture.

植物和丛枝菌根真菌 (AMF) 之间的关联影响植物性能和生态系统功能。最近的研究已将 AMF 相关细菌确定为参与 AMF-植物共生的合作伙伴：特定的内生细菌生活在 AMF 内部，菌丝球细菌定植于根外菌丝周围的土壤中。在这篇综述中，我们描述了植物-AMF-细菌连续体的概念，总结了当前的进展并提供了土壤微生物学的观点。首先，我们回顾了这个连续体中自上而下的碳流和自下而上的矿物质流（特别是磷和氮），以及 AMF-细菌相互作用如何影响营养物质（例如碳、磷和氮）的生物地球化学循环。 ）。其次，我们讨论了 AMF 如何与菌丝细菌或内生细菌相互作用来调节植物和 AMF 之间的养分交换，以及支撑这一连续体的可能分子机制。最后，我们探讨了菌丝圈研究的未来前景，以促进 AMF 和菌丝圈细菌在可持续农业中的利用。