J032 : Biological Function of the Mycovirus PoV in the Edible Mushroom Pleurotus ostreatus

PoV virus was found in Pleurotus ostreatus Halla strain, a bottle cultivated commercial strains of oyster mushroom in Korea. In this study, we attempt to cure the edible mushroom P. ostreatus Halla strain of the P. ostreatus mycovirus (PoV) in order to obtain an isogenic virus-free fungal strain as well as virus-infected strain towards contrast. Mycelial fragmentation, followed by being spread on a plate with nylon mesh filtrations resulted in a virus-free colony. Virus curing was verified with gel electrophoresis after dsRNA-specific virus purification and Northern blot analysis. For the Nortbern blot analysis of dsRNA was performed a hybridization with RDRP probe. The growth rate and mycelial dry weight of virus-infected P. ostreatus strain were compared to two virus-free isogenic strains using 11 different media. The virus-cured strain was observed higher growth rate than virus-infected strain on culture media czapex-dox, ME, sawdust, V8, and YMG media. In addition, we are currently exploring effects of PoV on fruiting body formation and mushroom yield. The fruiting body formation yield of virus-free P. ostreatus strain was significantly larger than virus-infected P. ostreatus strain. These results indicate that the presence of PoV affect the mycelial growth and fruting body formation of the P. ostreatus.