In vitro study of a possible fungistatic effect of the body surface mucus from garden snail (Helix pomatia, Helix aspersa) on plant pathogen Botrytis cinerea

In viticulture practices, technical cultivation practices and application of fungicides, specifically named botryticides, are important to control the grey mold, Botrytis cinerea. While conventional disease control is based upon applications of fungicides, options for controlling of grey mold in organic viticulture is limited. Resistance of the fungus and multiple drug resistance (MDR) require development of new disease control strategies. In vivo observation showed a reduced grey mold infection of grapes if covered with slime from garden snail. Hence, snail slime, commercial lectin (Helix aspersa agglutinin, HAA) from garden snail and bacteria isolated from snail slime were tested for antifungal or antagonistic activities against B. cinerea in vitro. Furthermore, fluorescein isothiocyanate labeled Helix-lectin (FITC-HPA) was used to detect terminal N-acetyl-galactosamine residues (GalNAc) on fungal cell wall surface. In our experiments, neither slime (after sterile filtration) nor commercial lectin nor slime bacteria were found to affect spore germination and mycelial growth. Binding of lectin was found to depend on media and age of the fungal mycelium.