The Extracellular Proteases Secreted in vitro and in planta by the Phytopathogenic Fungus Sclerotinia sclerotiorum

The proteolytic enzymes secreted by Sclerotinia sclerotiorum were characterized using mechanistic inhibitors, affinity chromatography and analytical electrophoresis. The proteolytic system mainly constituted of acidic proteases but a neutral protease (serine protease) was also found at the initial stage of plant infection by the fungus. In vitro and in planta protease profiles were shown to be similar. Properties of the enzymes produced were matched with the ambient pH indicating that the set of enzymes secreted reflected the environmental niche created during mycelial growth.