SREL
Reprint #2639
DEVELOPING TRANSGENIC ARABIDOPSIS PLANTS
TO BE METAL-SPECIFIC BIOINDICATORS
BETH
A. KRIZEK,1 VALERIE PROST,1 RATAN
MANI JOSHI,2 TERRY STOMING,2 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
(Received 22
March 2002; Accepted 3 July 2002)
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 (AHB1) to the P-glucuronidase (GUS) reporter
gene. Arabidopsis plants containing the AHB1::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
