In the roots of host plants, mycorrhizal fungi exchange the sugars plants produce for nutrients they absorb from the soil. To understand the basis for fungal symbiotic relationships with plants, DOE Joint Genome Institute researchers and longtime collaborators reported the first broad, comparative phylogenomic analysis of mycorrhizal fungi in the Feb. 23, 2015 edition of Nature Genetics. The results help researchers understand how the mutualistic association provides host plants with beneficial traits for environmental adaptation.