| Friday, February 25, 2005
| WEEDING OUT LAND MINES
|Gene-altered plant blushes when roots sense explosives.
A lethal problem just might be solved with
a leafy approach.: using genetically modified
plants to find land mines. Scientists at the
Danish firm Aresa Biodetection and the
University of Copenhagen have produced
a variety of thale cress (Arabidopsis thaliana)
that turns green to red when its roots encounter
nitrogen dioxide -- a by-product of land mines
that gradually evaporates from buried explosives.
Thale Cress naturally changes color under certain
conditions, says Aresa's founder Carsten Meier.
"We manipulated the plant's genetic switch so that
this variety changes color when it senses nitrogen
dioxide." A range of experiments have been performed
with Thale Cress, including growing in soil laced
with TNT solution and in boxes containing land mines.
Soon Meier hopes to test the plant on land mines in Bosnia.
"It's an interesting idea," says land mine expert
Bill Reid, who still notes several drawbacks, among
them the costs of defoliating minefields before sowing
the plants, and watering in arid climates. But Meier
thinks further research may yield strains able to
overcome such challenges.
Scientists have tried many techniques to loacte the
world's estimated 60 million land mines, from training
rats to sniff out explosives to using honeybees to collect
chemical samples. As yet, says Reid, "there is no silver bullet".
(abstracted from GEOGRAPHICA/NATGEOMAG by: Peter Gwin)
|posted by infraternam meam @ 11:52 AM