Figure 4.

The drawing summarizes the most important nutritional and energetic fluxes that characterize the tripartite association of the endobacterium thriving inside the AM fungus that is inside a plant cell. For simplicity, the endobacterium is represented only once on the left side, although it is also present in fungal extraradical structures. The major fluxes are represented by N and P, which are taken up by the fungus and delivered to both the bacterium and the plant. On the other hand, organic carbon produced by the photosynthesis flows towards the fungus and then towards the endobacterium.