[Genetic improvement in Vicia and favism. II. Glycosidase activity]

Glycosidase activities with starch and PNP-glycosides as substrates can be detected in the cotyledons, leaves, pods and teguments of Vicia faba beans. The mainly hydrolize alpha- and beta-glucosides, alpha- and beta-galactosides as well as starch. The amylase activity arises at very early stages of seed maturation and then rapidly decreases, whereas glycosidases increase up to the 30% of the beans dry weight before decreasing. The beta-glucosidase might play a role in regulating the metabolism of possibly haemolitic glycosides (i.e. vicine, convicine and L-DOPA glucoside) thus explaining the presence of this enzyme.