Dictyostelium caveatum mutants selected for a nystatin-resistant phenotype are cross-resistant to pisatin and other isoflavonoid phytoalexins

Abstract

Cellular slime mould amoebae can be induced to become resistant to an otherwise inhibitory concentration of pisatin, an isoflavonoid phytoalexin of pea, if they are first treated with a subinhibitory concentration. We report here the serendipitous isolation of pisatin-resistant mutants in the cellular slime mould Dictyostelium caveatum. However, the pisatin resistance phenotype of the mutants appears to have a different basis than the inducible pisatin resistance phenotype of the wild type.