SREL Reprint #2639

Developing transgenic Arabidopsis plants to be metal-specific bioindicators

Beth A. Krizek1, Valerie Prost1, Ratan Mani Joshi2, Terry Stoming2, and Travis C. Glenn1,3

1Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA
2Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, Georgia 30912, USA
3Savannah River Ecology Lab, University of Georgia, Aiken, South Carolina 29802, USA

Abstract: Deoxyribonucleic acid (DNA) microarrays provide a means to assess genome-wide expression patterns after exposure of an organism to different xenobiotics. Potential uses for this technology include identification of unknown toxicants, assessment of toxicity of new compounds, and characterization of the cellular mechanisms of toxicant action. Here we describe another use of DNA microarrays in toxicant-specific gene discovery. Combining results from two DNA microarray experiments, we have identified genes from the model plant Arabidopsis thaliana that are induced in response to one but not other heavy metals. The promoters of these genes should be useful in developing metal-specific transgenic biomonitors. To test this idea, we have fused the promoter of one of the newly identified Ni-inducible genes (AHBl) to the β-glucuronidase (GUS) reporter gene. Arabidopsis plants containing the AHBl::GUS transgene show reporter gene activity when they are grown on media containing Ni but not when grown on media containing Cd, Cu, Zn, or without added metals. Thus, this approach has resulted in the creation of a transgenic strain of Arabidopsis that can report on the presence and concentration of Ni in plant growth media. Such transgenic models can serve as cheap and efficient biomonitors of bioavailable heavy metal contamination in soils and sediments.

Keywords: Biomonitors, Heavy metals, Bioavailability, Environmental contaminants, DNA microarrays

SREL Reprint #2639

Krizek, B. A., V. Prost, R. M. Joshi, T. Stoming, and T. C. Glenn. 2003. Developing transgenic Arabidopsis plants to be metal-specific bioindicators. Environmental Toxicology and Chemistry 22:175-181.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).