IMMUNOCYTOCHEMICAL LOCALIZATION OF A 32-KDA PROTEASE FROM THE NEMATOPHAGOUS FUNGUS VERTICILLIUM-SUCHLASPORIUM IN INFECTED NEMATODE EGGS

Fluorescein-labeled anti-rabbit antiserum showed that a serine protease designated P32, produced by the nematophagous fungusVerticillium suchlasporium, is secreted during infection of nematode eggs. Increased fluorescence in appressoria of the fungus on eggshells of the plant parasitic nematodeHeterodera schachtii indicated the presence of P32 in these fungal structures. Appressoria are involved in host penetration and these results support a role for P32 in the pathogenicity of the fungus to nematode eggs. These findings agree with similar results of entomogenous fungi penetrating the insect cuticle. © 1992 Academic Press, Inc.