A sensitive transgenic plant system to detect toxic inorganic compounds inthe environment

We describe a transgenic plant-based assay to study the genetic effects of heavy metals. Arabidopsis thaliana plants carrying a beta -glucuronidase (G US) marker gene either with a point mutation or as a recombination substrat e were used to analyze the frequency of somatic point mutations and homolog ous recombination in whole plants. Transgenic test plants sown on media con taminated by the salts of the heavy metals Cd2+, Pb2+, Ni2+, Zn2+, Cu2+, an d As2O3 exhibited a pronounced uptake-dependent increase in the frequencies of both somatic intrachromosomal recombination and point mutation. The tes t was applied to monitor the genotoxicity of soils sampled in sites contami nated with several heavy metals. Our results indicate that this is a highly sensitive system for monitoring metal contamination in soils and water.