ABSTRACT
Monoclonal antibodies were raised to Colletotrichum lindemuthianum (Sacc. & Magn.) Briosi & Cav. infection structures which had been isolated from leaves of Phaseolus vulgaris L. by isopycnic centrifugation and immunomagnetic separation. One of the antibodies, UB29, recognized a carbohydrate epitope in a 200 kDa glycoprotein present on the surface of conidia, germ-tubes and appressoria when they developed on host tissue. Intracellular hyphae were not labelled. Immunogold labelling showed that the antigen was confined to the extracellular matrices around such structures. No such antigen was detected by immunofluorescence or Western blotting when the fungus developed in vitro. UB29 recognized a glycoprotein of identical Mr located in the epicuticular wax layer of uninoculated bean hypocotyls. The results suggest that a host epicuticular glycoprotein is present in the extracellular matrices of fungal structures during growth on the plant surface.
