MODEL RELEASED. Plant-fungi research. Researcher's hands holding a container in which leek, carrot, myrtle, and lettuce plants are growing in sterile soil. This research involves arbuscular mycorrhizal (AM) fungi, an an example of mycorrhizal symbiosis. These fungi are mutualistic symbionts living in the roots of many land plant species. Extensive underground fungal networks connect the roots of different plants and are essential for the uptake of soil nutrients and their transfer to the host plants. Photographed at the University of Pisa, Italy.