The Endoparasitic Nematophagous Fungus Meria coniospora Infects Nematodes Specifically at the Chemosensory Organs

Abstract

SUMMARY: Conidia of the endoparasitic fungus Meria coniospora infected the bacterial-feeding nematode Panagrellus redivivus at specific sites, namely the mouth region and in male nematodes also in the tail. Plant-parasitic nematodes were also infected in other parts of the body. The specific infection sites in P. redivivus were the sensory organs, which are the sites of chemoreception. Blocking of chemoreceptors by adhered conidia of M. coniospora caused a complete loss of the ability of nematodes to be attracted to different sources of attractants. Inhibition of conidial adhesion by means of sugar haptens suggested a lectin-carbohydrate interaction. Out of 21 sugars only N-acetylneuraminic acid inhibited the adhesion, indicating the importance of sialic acids in the infection process. Reduction of conidial adhesion by treatment of nematodes with neuraminidase further supported this view.