US and UK scientists have developed genetically modified plants to mop
up pollutants. Researchers at the University of York devised genetically
modified (GM) plants that can clean carcinogenic residues from military
explosives. To achieve this, they incorporated genes from microbes which can
break down the explosive RDS into an Arabidopsis species.
Arabidopsis was the first plant to have its entire genome sequenced as
is commonly used as a model organism.

Meanwhile, scientists at the University of Washington genetically
altered poplar trees to absorb toxins out of contaminated ground water,
offering a cost-effective way of cleaning up environmental pollutants.

This research is part of a growing scientific field known as
phytoremediation, which aims to use vegetation to remove hazardous
substances from contaminated land or water.

"Phytoremediation is basically a solar-powered pollutant-removal
system," said Sharon Doty, assistant professor of forest resources at the
University of Washington. "It uses the plant's natural ability to extract
chemicals from water, soil, and air."

As well as being effective, using plants for environmental clean up is
more than ten times cheaper than other technologies. It is also less
intrusive and more aesthetically pleasing, she said.

GM trees in action

Naturally occurring plants can be used for phytoremediation, but they
are often too slow.

Doty?s GM poplar trees sucked 91 per cent of the toxin
trichloroethylene from a liquid solution, metabolising the pollutant into
harmless by products.

Compared to ordinary poplars, the GM trees removed three times more of
the toxin and metabolised it 100 times faster. Trichloroethylene is the most
common groundwater contaminant in the US.

University of York researchers Rosamond Jackson, Neil Bruce and
colleagues reported that genetically modified plants removed carcinogenic
RDX from contaminated liquids and soil far faster than unaltered plants.

"The studies here illustrate that these genes could be engineered into
plant species suited to growth on military training ranges and used to
remediate RDX," the authors wrote.

[www.scenta.co.uk]