Old Enzyme, New Role: The ?-Glucosidase BglC of Streptomyces scabiei Interferes with the Plant Defense Mechanism by Hydrolyzing Scopolin

The beta-glucosidase BglC fulfills multiple functions in both primary metabolism and induction of pathogenicity Streptomyces scabiei, the causative agent common scab root tuber crops. Indeed, this enzyme hydrolyzes cellobiose cellotriose to feed glycolysis with glucose directly modifies intracellular concentration these cello-oligosaccharides, which are virulence elicitors. inactivation bglC led unexpected phenotypes such as constitutive overproduction thaxtomin A, main determinant S. scabiei. In work, we reveal a new target substrate BglC, phytoalexin scopolin. Removal moiety scopolin generates scopoletin, potent inhibitor A production. hydrolysis by displayed inhibition kinetics, contrasts typical Michaelis–Menten saturation curve previously observed for degradation its natural cellobiose. Our therefore, reveals that targets cello-oligosaccharide elicitors emanating from hosts generated host defense mechanisms, thereby occupying key position fine-tune production A.