Arbuscular mycorrhizal fungi conducting the hyphosphere bacterial orchestra

More than two-thirds of terrestrial plants acquire nutrients by forming a symbiosis with arbuscular mycorrhizal (AM) fungi. AM fungal hyphae recruit distinct microbes into their hyphosphere, the narrow region of soil influenced by hyphal exudates. They thereby shape this so-called second genome of AM fungi, which significantly contributes to nutrient mobilization and turnover. We summarize current insights into characteristics of the hyphosphere microbiome and the role of hyphal exudates on orchestrating its composition. The hyphal exudates not only contain carbon-rich compounds but also promote bacterial growth and activity and influence the microbial community structure. These effects lead to shifts in function and cause changes in organic nutrient cycling, making the hyphosphere a unique and largely overlooked functional zone in ecosystems.

Automated summary

More than two-thirds of terrestrial plants form a symbiotic relationship with arbuscular mycorrhizal (AM) fungi to acquire nutrients. The hyphal exudates of AM fungi not only contain carbon-rich compounds, but also promote bacterial growth and activity, and influence microbial community structure, leading to changes in organic nutrient cycling. This makes the hyphosphere an important but often overlooked functional zone in ecosystems.