Structural and functional genomics of symbiotic arbuscular mycorrhizal fungi.

The absorbing organs (roots, rhizomes) of nearly all terrestrial plant families host an intimate symbiotic association, called a mycorrhiza, with specialized functional groups of soil fungi. The most common type of root symbiosis is the arbuscular mycorrhiza where soil fungi interact with a tremendous diversity of plant species, including many forest trees and agricultural, horticultural, and fruit crops (Gianinazzi et al., 2002). The fungi involved are very ancient microorganisms compared to other true fungi. Fossil data and molecular phylogenetic analyses indicate that their origin dates back to the Ordovician-Devonian era some 460 to 400 million years ago (Remy et al., 1994; Redecker et …