English: Representative microbial networks in different plant habitats
The figure illustrates microbial communities in the soil, air, rhizosphere, phyllosphere, and inside plant tissue (endosphere). In each of these habitats, microbes (represented by colored circles) could interact positively, negatively, or do not interact with other microbes (no lines). Specific microbes, often defined as “hub” or “keystone” species (circles highlighted in bold), are highly connected to other microbes within the networks and likely exert a stronger influence on the structure of microbial communities. (a) Root-associated microbes mainly derive from the soil biome. (b) Leaf-associated microbes originate from various sources such as aerosols, insects, or dust. (c) Relocation between aboveground and belowground microbiota members. The combination of microbe-microbe and host-microbe interactions is proposed to be critical for the establishment of the plant microbiota.