Mutagenicity of atrazine: a maize-microbe bioassay.

A water-soluble extract from maize plants grown in the presence of atrazine contained a mutagenic agent(s) when tested on strains of yeast. Atrazine alone or control plants not treated with atrazine did not express mutagenic properties. The reversion frequency at the waxy locus in pollen grains from plants grown in atrazine was higher than in control plants. We suggest that atrazine may be degraded by the plant into environmental mutagenic agents.