Part of the show Pain and Painkillers, and Chemistry of everyday life
Scientists in Denmark have produced a genetically modified cress plant that can detect landmines in soil. Carsten Meier and his colleagues from Aresa Biodetection, the company they have set up to develop the GM strain of Arabidopsis or Thale cress, have genetically modified the plant to make it change colour from green to red when it grows near an unexploded mine. Nitrogen dioxide gas released by the breakdown of TNT, the explosive used in 99% of landmines, triggers the plant to produce anthocyanin, the naturally-occurring plant pigment that colours beetroot and makes autumn leaves turn red. The colour change takes about 3 weeks to develop, although the scientists don't yet know how sensitive the cress is at detecting all the landmines in an area, and whether the technology will work in all types of soil. There are also concerns that open fields full of lush cress could attract livestock into the mined areas. But with an estimated 110 million landmines claiming 2000 victims per week across 70 countries worldwide, and the best de-mining personnel capable of clearing just 2 square metres of land a day, Meier and his team are confident that their genetically modified cress plant can make a significant contribution to the detection and clearance of landmines, particularly from agricultural land.