Effects of Grapevine Metabolism on the Mutagenicity of Pesticides

¹ University of Guelph, Guelph, Ontario, Canada, N1G 2W1.

The short term Salmonella bio-assay for mutagens or "Ames test" employs a rat liver microsomal extract to evaluate the mutagenicity of any metabolites. Recently, plant extracts (S14 supernatant) have been used to show that plant metabolism also can alter the mutagenicity and toxicity of pesticides in this bio-assay. In the present study, comparable S14 supernatants were prepared from roots and young stems of grapevine cuttings (Vineland hybrid Ventura) and used in studies on the mutagenicity of a fungicide, CAPTAN, and an insecticide, PENTAC. The combination of S14 supernatant and pesticide exhibited a complex profile of activation or deactivation depending on the type of tissue and bacterial tester strain. With CAPTAN a slight activation was observed in the TA98 strain suggesting a frameshift mutagen and a deactivation in the TA100 strain, which detects base substitutions. A slight metabolic activation was observed with PENTAC in both strains.