PARTIAL CHARACTERIZATION OF THE EXTRACELLULAR-MATRIX RELEASED ONTO HYDROPHOBIC SURFACES BY CONIDIA AND CONIDIAL GERMLINGS OF COLLETOTRICHUM-GRAMINICOLA

The extracellular matrix (ECM) released by conidia of Colletotrichum g raminicola when incubated on artificial hydrophobic substrata was inve stigated. Time-course experiments revealed that proteins and carbohydr ates were released in the ECM of both ungerminated and germinated coni dia. Stains for protein and carbohydrate revealed that part of the ECM remained attached to the substratum after the fungus had been removed . The ECM isolated from substrata where ungerminated conidia had adher ed and from substrata where germinated conidia had adhered exhibited t he same profiles when analysed by SDS-PAGE for proteins and glycoprote ins and by HPLC for carbohydrate analysis. The ECM was found to be com posed of glycoproteins with a molecular weight of around 200 kDa. Degl ycosylation of the isolated ECM material resulted in the release of a protein with a molecular weight of approx. 116 kDa, indicating that th e original protein was extensively glycosylated. Carbohydrate analysis demonstrated that mannose was the predominant sugar. That the ECM rem ained attached to the surface of the hydrophobic substrata suggests th at it has a role in adhesion. (C) 1998 Academic Press.