Leptosphaeria maculans, a fungal pathogen of Brassica napus, secretes a subtilisin-like serine protease

Leptosphaeria maculans,a fungal pathogen of Brassica napus, secretes large amounts of a 28 kDa protein (SP2) in liquid culture. This protein shows high sequence similarity to secreted serine proteases from other ascomycetes and is the major component of culture filtrate with protease activity, as analysed on casein zymogels. The sp2 gene is expressed during infection of B. napuscotyledons when L. maculans hyphae are growing between mesophyll cells, as well as at later stages when the fungus invades the vascular tissue.