A genetically-mutated relative of the common cabbage may have an answer to cleaning up soil in areas of the world contaminated by residues of high explosives, researchers say.
When trinitrotoluene (TNT) is detonated, the damage is not limited to just the effects of the explosion; particles of the TNT can seep into the surrounding soil as a residue that can poison the soil for plant life, they explain.
It doesn't easily break down, and it can be carried into streams and rivers by water moving through the soil, they say.
A humble plant related to cabbage may be a surprising way to clean up millions of acres of land contaminated by such explosive residue, scientists at the University of York in England say they've discovered.
One variety of the plant species Arabidopsis thaliana possesses a genetic mutation that allows it to thrive in concentrations of TNT that would harm the growth of its un-mutated relatives, they report in the journal Science.
More than just resisting the TNT, the plant can take up the residue and then imprison it in highly stable portions of its cell walls.
Once entombed there, "we expect that TNT is not biologically available," even after the plant dies and has decomposed, says biologist Neil Bruce of the university's Center for Novel Agricultural Products.
Bruce has spent years breeding and engineering plant species with an eye for soil remediation.
While Arabidopsis might not be the plant of choice for widespread TNT cleanup, other plants with the same mutation or engineered to have it, such as grasses, could offer a widely-available solution to the problems at contaminated locations such as military ranges and manufacturing waste sites, the researchers suggest.
In the United States alone, an estimated 38,000 square miles of land — an area bigger than the state of Maine — contaminated to some degree with munition constituents such as TNT.
"These sites are large, so you need low-cost, sustainable technology" that can check on contamination, Bruce says, adding, "plants are the only option to be able to do this."
In addition to TNT, other chemical explosives, such as RDX — which is often found in the same places — could be broken down with genetically-modified plants, experts suggest.
RDX is considered a significant concern since it is highly toxic, water-soluble and has been listed by the U.S. Environmental Protection Agency as a "possible human carcinogen."
