TRANSFORMATION OF THE EDIBLE FUNGI, PLEUROTUS-OSTREATUS AND VOLVARIELLA-VOLVACEA

A transformation system is described for the edible mushrooms Pleurotu s ostreatus and Volvariella volvacea. The system developed is based on a positive selection strategy using the trp3(iar) gene from Coprinus cinereus, which confers resistance to the antimetabolite 5-fluoroindol e. Transformation frequencies were low in both species. Southern blot analysis confirmed the integration of transforming DNA into the genome of transformants and indicated the presence of tandemly duplicated co pies of the plasmid in some of these transformants. The system has pot ential for introducing beneficial traits such as enhanced substrate bi oconversion and faster sporophore development.