Abstract
A novelβ-glucosidase of Botrytis cinerea, shown to be very inducible in the lesions, was examined with respect to its pathogenicity. By activity staining, the occurrence ofβ-glucosidase activity was noted at the surface and middle lamella of tissues in the lesions. When the purifiedβ-glucosidase was reacted with apple fruit tissues, polysaccharides were released, endogenous K+ ions of the plant leaked out, and the tissues were macerated. Thus, it was suggested that the enzyme can degrade the apple fruit tissues by itself.