Cutinase is produced by a variety of fungal plant pathogens, and its activity was first detected in the fungus, Penicillium spinulosum. In studies of Nectria haematococca, a fungal pathogen that is the cause of foot rot in pea plants, cutinase has been shown to play key roles in facilitating the early stages of plant infection. It is also suggested that fungal spores that make initial contact with plant surfaces, a small amount of catalytic cutinase produces cutin monomers which in turn up-regulate the expression of the cutinase gene. This proposes that the expression pathway of cutinase in fungal spores is characterized by a positive feedback loop until the fungus successfully breaches the cutin layer; however, the specific mechanism of this pathway is unclear. Inhibition of cutinase has been shown to prevent fungal infection through intact cuticles. Conversely, the supplementation of cutinase to fungi that are not able to produce it naturally had been shown to enhance fungal infection success rates.
