22 August 2008

GM plants detect landmines and turn red

Cosmos Online
Genetically-modified plants that turn red when they grow in the presence of explosives are being trailed for their effectiveness to detect landmines.

Red for landmine: A diagram from Aresa showing the process of TNT degrading to nitrogen dioxide which is detected by the GM tobacco plants, turning them red. Credit: Aresa Biotechnology

SYDNEY: Genetically-modified plants that turn red when they grow in the presence of explosives are being trailed for their effectiveness to detect landmines in South Africa.

Scientists at Stellenbosch University, in collaboration with a Danish biotechnology firm, are testing a type of tobacco plant that produces the red pigment anthocyanin in the presence of breakdown products of TNT (trinitrotoluene). TNT is an explosive often found in landmines.

“Usually tobacco plants only produce this pigment in their flowers, resulting in their pink colour, but in the GM plants, the presence of a particular compound in the soil, will also induce pigment production in the leaves – resulting in red plants,” said a statement from the university.

Persistent danger

Landmines are a persistent danger in 78 countries – such as Angola, Afghanistan, Cambodia, Iraq and Nepal – and injure or kill up to 20,000 people annually, according to the United Nations. Detecting and clearing landmines is expensive, dangerous and labour-intensive. If successful, scientists behind the new technology hope that it could make detecting landmines safer and easier.

“Landmines still hold a significant danger for thousands of people around the world, many of them in Africa”, said Estelle Kempen an agricultural scientist at the university. “[We] support any attempt to diminish the threat to human lives that landmines hold.”

Researchers at the Copenhagen-based company, Aresa Biotechnology, have transferred a gene for a receptor which detects nitrogen dioxide from a type of cress plant in which it was originally developed, to tobacco plants, which are hardier.

“The tobacco plant is believed to be more robust, contains larger biological mass, does not have the same need for irrigation, can stand heavy rain falls and grows naturally under [many] climatic conditions where landmine fields are present” said Steen Thaarup, CEO of Aresa.


Aresa said that they successfully tested the technology in 2005 in collaboration with the Danish Demining Centre, part of the Danish Army. They were able to show the plants turning red when growing on or near three different types of landmines.

Further field trials with the plants, which Aresa have dubbed ‘RedDetect’, took place in Serbia last year and the results are due to be announced next month. The aim of the South African leg of trials, likely to commence next year, is to test the technology in different set of climatic and environmental conditions.

Lou De Filippis, an environmental scientist at the University of Technology in Sydney, Australia, agreed that tobacco might be helpfully used to detect landmines and added that this is an “area of research with great interest and potential.”

Aresa says that if the plants make it successfully through trials and do end up being used in the field, they will be partly sterile to prevent them from breeding. The company added that planting them might involve remote controlled vehicles to clear foliage from sites that are potentially contaminated with landmines and a device called a ‘hydroseeder’ that sows the seeds with a high-pressure water jet.


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