Mucoromycotina fine root endophyte engages in a nutritionally mutualistic symbiosis with Arabidopsis thaliana.

A wild-isolated Mucoromycotina fungus forms a functional nutritional mutualism with Arabidopsis thaliana, demonstrating bidirectional nutrient exchange without affecting plant growth.

• Why it matters: Arabidopsis is traditionally considered incapable of forming mycorrhizal associations, limiting understanding of plant-fungal symbiosis mechanisms and evolution, especially in model species.
• What they did: Researchers used microscopy and isotope tracing to show that Lyc-1 colonizes Arabidopsis roots extensively and engages in nutrient exchange, establishing a mycorrhiza-like relationship in 20 Arabidopsis plants.
• The result: This discovery positions Arabidopsis as a model to study plant-fungal symbiosis, suggesting alternative pathways may control such interactions and advancing knowledge of their molecular and evolutionary basis.