Signal and nutrient exchange at biotrophic plant–fungus interfaces

Biotrophic interfaces are formed in mutualistic and parasitic plant–fungus interactions. They result from coordinated developmental programs in both partners and represent specialized platforms for the exchange of information and nutritional metabolites. New data on the establishment and the components of functional interfaces have been obtained in a number of ways. First, by isolation of symbiotically defective mutants; second, by characterization of new genes and their products; and, third, by the identification and localization of components of biotrophic interfaces, such as cell-wall proteins, H +-ATPases and nutrient transporters.