Professor Boyce Thompson Institute for Plant Research
Most vascular flowering plants have the ability to develop endosymbioses with arbuscular mycorrhizal (AM) fungi. These mutualistic associations develop in the roots where, through hyphal connections to the rhizosphere, the AM fungi deliver phosphate directly to the root cortex and in return obtain carbon from the plant. The symbiosis originated over 450 MYA and it is speculated that ancestral AM fungi enabled plants to colonize land. Today, the AM symbiosis occurs in almost all terrestrial ecosystems and has a major impact on plant mineral nutrition, carbon cycling and consequently on ecosystem productivity. Our research focuses on development and functioning of AM symbiosis, which we explore using a combination of genetics, genomics and cell imaging approaches. Using phylogenomics we identified a set of plant genes (~ 138 genes) broadly conserved in AM host plants that we predict should play significant roles in symbiotic development and/or function. Initial evidence suggests that this prediction is true. We continue to determine how these genes function to modify aspects of root cell biology or metabolism to enable accommodation of the fungus within the root cells. Additionally, the application of fluorescence microscopy, and electron microscopy coupled with tomography, has provided new views of the endosymbiotic plant-fungal interface which challenge our thinking about the AM symbiosis.