Isolation and regeneration of protoplasts from two strains of the ericoid mycorrhizal fungus Oidiodendron maius: Sensitivity to chemicals and heavy metals

Protoplasts of the ericoid mycorrhizal fungus Oidiodendron maius have been isolated from the mycelium of two strains, and the conditions for their pro duction, regeneration and storage have been optimized. The percentage of pr otoplasts containing nuclei has been determined, as well as sensitivity to some chemicals. Protoplasts from a strain isolated from soils polluted with heavy metals proved to be sensitive to Cd2+ at concentrations which did no t inhibit mycelial growth. Direct Zn measurements indicate that the cell wa ll binds Zn2+, and provide the structural basis for an exclusion mechanism.