Un assemblage de génomes hautement contigus révèle des sources de nouveauté génomique chez le champignon symbiotique Rhizophagus irregularis

Most plants need help to obtain and absorb nutrients and water. Many get this support via symbiotic relationships with underground fungi called arbuscular mycorrhizal (AM) fungi. While scientists know a lot about how these fungi benefit plants, they’re just beginning to understand the genes and DNA of AM fungi. In this study, researchers created a nearly complete genetic map (or genome) of a common AM fungus called Rhizophagus irregularis using advanced DNA sequencing techniques.

With this genetic map, the researchers  identified important genes and DNA patterns. They found that many genes related to moving nutrients in and out of cells were around before AM fungi even evolved, showing these genes have been present for an exceptionally long time. They also discovered new genes that only exist in this fungal group. Another key finding was that recently evolved areas in the DNA produce many small RNA molecules, which seem to help the fungus control its genetic information. This detailed map gives scientists new insights into how AM fungi have evolved to live and grow as obligate partners to plants.