ANALYSIS OF DIFFERENTIATION AND DEVELOPMENT OF THE SPECIALIZED INFECTION STRUCTURES FORMED BY BIOTROPHIC FUNGAL GIANT PATHOGENS USING MONOCLONAL-ANTIBODIES

Monoclonal antibodies have been used to study the differentiation and development of the specialized infection structures formed in the Colletotrichum-bean and powdery mildew - pea interactions. In the Colletotrichum lindemuthianum - bean interaction, monoclonal antibodies have been used to show that the extracellular matrices associated with conidia, germ tubes, and appressoria differ in composition and that the extracellular glycoproteins are organized into specific regions of the fungal cell surface. Monoclonal antibody UB27 has been used to show that the plasma membrane of appressoria is differentiated into distinct domains, with the integral membrane glycoprotein identified by UB27 being excluded from the pore region. UB25 recognizes a glycoprotein located specifically in the cell wall/matrix of intracellular hyphae and is expressed only during the biotrophic phase of development. In the Erysiphe pisi - pea interaction, UB8 and UB10 identify glycoproteins specific to the haustorial plasma membrane within the haustorial complex. Monoclonal antibodies that recognize the extrahaustorial membrane have shown that this membrane contains specific components, as well as glycoproteins in common with the host plasma membrane. UB8 has been successfully used to isolate a gene sequence coding for the protein antigen, by immunoscreening a cDNA expression library prepared from infected epidermis. An antibody that recognizes the plant endoplasmic reticulum has been used to show that this structure reorganizes around the developing haustorial complex in pea epidermal cells.