Beta-glucosidase acting as a preformed defense system. Hydrolyzes the bisdesmosides avenacosides A and B to 26-desgluco-avenacosides exhibiting fungicidal activity. Can use beta-fucoside > beta-glucoside > beta-galactoside > beta-xyloside as substrates, but not alpha-glycosides, beta-thioglucosides and disaccharides (By similarity). avenacoside B + H2O = 26-desgluco-avenacoside B + D-glucose Heteromultimer with P60A in a 1:1 stoichiometry. Aggregates to form the fibrillar stromacentre. Found in a fibrillar spherulite called stromacentre. Belongs to the glycosyl hydrolase 1 family.