Glycoproteins recognised by monoclonal antibodies UB7, UB8 and UB10 are expressed early in the development of pea powdery mildew haustoria

Abstract

A new monoclonal antibody (MAb) raised against haustorial complexes isolated from pea leaves infected with the powdery mildew fungus Erysiphe pisi is described. The antibody (designated UB10) recognises a 45 kDa N-linked glycoprotein which is specifically located in the haustorial plasma membrane. This glycoprotein is clearly distinct from a previously characterized 62 kDa glycoprotein (identified with MAb UB8) which is also specifically located in the haustorial plasma membrane. These antibodies were used, along with MAb UB7 which binds to a major 62 kDa glycoprotein in the cell wall and plasma membrane of both haustoria and surface hyphae, to label haustoria within epidermal strips from infected pea leaves using indirect immunofluorescence. Different stages of haustorial development can be observed using this procedure and the results showed that all three glycoproteins recognised by the MAbs are expressed early haustorial development.