Overcoming Glucosinolate-Myrosinase-Isothiocyanate Defense System by Plant Pathogenic Fungi

Natural compounds play an important role in shaping living plant responses. The resistance of plants is dependent on the formation and production of antimicrobial compounds of secondary metabolites. Glucosinolates (GSLs) are the main source of phytoanticipin in Brassicaceae and other plant families. The biological activity of glucosinolates are dependent on the release of various toxic compounds due to hydrolysis by myrosinase, isothiocyanate (ITC) is glucosinolate-breakdown products that inhibit the growth of microorganisms. In this review, we aim to understand how fungal pathogens overcome the glucosinolate-myrosinase-isothiocyanate system. The pathogens overwhelm the plant's defense system in various ways and disable each component of the system. Many plant pathogens may not cause tissue damage or activation of the glucosinolate-myrosinase-isothiocyanate system, others degrade or transforms the intact GSLs to less or non-toxic products, or inhibit the hydrolysis of GSLs catalyzed by myrosinase, or formed special mechanisms to detoxify toxic GSLs degradation products.