A transformation system is described for the edible mushrooms
Pleurotus ostreatus and Volvariella volvacea. The system
developed is
based on a positive selection strategy using the trp3iar
gene from Coprinus cinereus, which confers resistance to the antimetabolite
5-fluoroindole. 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 copies of the plasmid in some of these
transformants. The system has potential for introducing beneficial
traits such as enhanced substrate bioconversion and faster
sporophore development.