Proteases from phytopathogenic fungi and their importance in phytopathogenicity

Phytopathogenic fungi, causal agents of some of the world's most serious plant diseases, can significantly reduce yields during large-scale agricultural production. Among the numerous hydrolytic enzymes they produce for nutritional and/or pathogenicity purposes, hydrolases and proteases are required for their growth and survival. The present review focuses on extracellular and/or secretory proteases from phytopathogenic fungi. Several extracellular proteases have been identified that contribute to fungal growth, infection structure formation, cell wall degradation, proteolytic processing of pathogenesis-related proteins and that act as elicitors of defense responses. In this review, the positive correlation between protease secretion and disease aggressiveness and/or necrosis is highlighted. The involvement of various fungal proteases in pathogenic mechanisms makes them potential targets for designing protease inhibitors that may provide an improved way to combat plant diseases, which in turn will reduce dependence on fungicides.