May play a role in plant defense against pathogens. Hydrolysis of (1->3)-beta-D-glucosidic linkages in (1->3)-beta-D-glucans. By infection with a virulent strain of P.syringae pv. maculicola (PubMed:1824335). Induced by infection with the biotrophic powdery mildew pathogens Golovinomyces cichoracearum and Blumeria graminis (PubMed:16473969). Induced by infection with the turnip vein clearing virus (TVCV) and cucumber mosaic virus (CMV) (PubMed:23656331). Belongs to the glycosyl hydrolase 17 family.