Tripartite symbiosis is a type of symbiosis involving three species. This can include any combination of plants, animals, fungi, bacteria, or archaea, often in interkingdom symbiosis.
Ants of Attini cultivate fungi. Microfungi, specialized to be parasites of the fungus gardens, coevolved with them.
Allomerus decemarticulatus ants use Trimmatostroma sp. to create structures within Hirtella physophora. The fungi are connected endophytically and actively transfer nitrogen.
The mycobiont in a lichen can form a relationship with both cyanobacteria and green algae as photobionts concurrently.
Rhizobia are nitrogen-fixating bacteria that form symbiotic relationships with legumes. Sometimes, this is aided by the presence of a fungal species. This is most effective in undistributed soil. The presence of mycorrhizae can improve the rhizobial-liquorice nutrient transfer in droughts. Soybeans in particular can improve their ability to withstand soil salinity with the presence of both rhizobium and mycorrhizae.