Extracellular hydrolytic enzymes in the fungal genus Verticillium: adaptations for pathogenesis

The insect and plant pathogens within the fungal genus Verticillium showed enzymatic adaptation (production and regulation) directed to the degradatio n of some of the polymers found in the integument of their respective hosts . For example, the facultative plant pathogens (V. albo-atrum and V. dahlia e) produced greater levels of cellulase and xylanase than the facultative i nsect pathogen (V. lecanii). Verticillium lecanii produced extracellular su btilisin-like protease when grown in insect cuticle medium but not in plant cell wall medium, while the plant pathogen V. albo-atrum showed a diminish ed regulatory component in the production of this enzyme. The opportunistic pathogens (I! fungicola and V. coccosporum) and the saprobic species (Ci r exianum) were less specific in the production and regulation of several pro teases as well as cellulases and xylanases. A dendrogram based on cluster a nalysis compiled from fungal API-ZYM profiles showed commonalties in a broa d array of extracellular enzymes within a host-pathogen group (i.e, insect or plant pathogen). The opportunistic pathogens were dispersed throughout t he dendrogram, suggestive of the diversity in type and expression of extrac ellular enzymes.