Description Of The Relationship
In this relationship the fungus has almost direct access to the plant's glucose, which is produced by photosynthesis. The plant then has access to the AM's large surface area, which is used to absorb extra water and inorganic minerals that are found in the soil. Another benefit for the plant is that it receives protection from disease due to the protective covering of its roots by the AM. Plants on their own have a hard time getting phosphate from the soil. The mycelium that is associated with the AM can access the phosphorus fairly easily and make it readily available  .
The fungus from the order Glomales that is associated with AM symbiosis are obligate biotrophs, asexually reproducing and forming multinucleate spores. The fungus only starts to grow when there is a presence of plant roots. Once the hyphae penetrate the root cells, tree-like structures (arbuscules) are formed in each cell. In the arbuscules is where nutrient exchange happens and is the key structure in this relationship .