Mycorrhizae are examples of

Mutualism is a type of symbiosis in which both species profit from the relationship. Symbiotic relationships between plants and fungi have been found to create mutual relationship (Mycorrhizae). 

In these associations, the fungal symbiont obtains phosphorus from the soil and passes it on to the plant. Other advantages of plants with such relationships include resistance to root-borne diseases, tolerance to salinity and drought, and an overall improvement in plant growth and development. The plant, on the other hand, provides the fungus with carbohydrates produced by photosynthesis.