An Efficient PEG/CaCl₂-Mediated Transformation Approach for the Medicinal Fungus Wolfiporia cocos.

Sclerotia of Wolfiporia cocos are of medicinal and culinary value. The genes and molecular mechanisms involved in W. cocos sclerotial formation are poorly investigated because of the lack of a suitable and reproducible transformation system for W. cocos. In this study, a PEG/ CaCl₂-mediated genetic transformation system for W. cocos was developed. The promoter Pgpd from Ganoderma lucidum effectively drove expression of the hygromycin B phosphotransferase gene in W. cocos, and approximately 30 transformants were obtained per 10 μg DNA when the protoplast suspension density was 10(6) protoplasts/ml. However, no transformants were obtained under the regulation of the PtrpC promoter from Aspergillus nidulans.