Denmark: The delicate business of finding buried land-mines might get a lot less nerve-racking with the invention of genetically engineered plants that turn red when their roots encounter explosives in the soil.
If the system works as well in the field as it has in the lab, mine-detection teams could spray seeds over large expanses of land where explosives are believed to be buried, then wait a few weeks and look for the places where the plants are growing red.
The plants were designed at Aresa, a small biotechnology company in Copenhagen. The team worked with a mutant version of the mustard-family plant Arabidopsis thaliana - a ubiquitous roadside weed and popular workhorse for plant geneticists. The mutant plant lacks a gene that it needs to make a red pigment.
The team gave the plants substitute copies of that gene. But they linked it to an added bit of genetic code so that it would operate only in the presence of nitrogen dioxide - a chemical that is released by soil bacteria as they break down the nitrogen-rich chemicals that leach from land-mines.
The plants have been additionally engineered so they do not produce seeds without laboratory help, a safeguard to prevent their spreading in the wild, said Mr Simon Ostergaard, Aresa's managing director. The research gained attention in Europe last week when the company filed for a patent.