A team at the University of Colorado, USA, led by Professor June Medford, has developed plants that can detect bombs. Based on the fact that the receptor proteins in plant DNA respond to threatening stimuli by releasing chemicals called terpenoids, which cause changes in a plant’s leaf, this natural defence reaction has been the basis of work into detecting explosives. A computer programme designed to manipulate the reaction in plants, enables the researchers to teach the plant to respond in the same way to chemicals found in explosives and pollution in air and water by changing colour – a reaction that could be detected by satellites. The university team has now been awarded a US $7.9 million grant from the US Defense Threat Reduction Agency to exploit the development operationally