By Tamar Kahn

Scientists from the University of Stellenbosch have teamed up with Danish
biotechnology firm Aresa to test a genetically engineered tobacco plant that
turns red when it grows near land mines, offering hope of a cheap way to
help clear fields in post-conflict zones.
More than 80 countries are affected by land mines. Angola, Afghanistan,
Burundi, Bosnia- Herzegovina, Cambodia, Chechnya, Colombia, Iraq, Nepal and
Sri Lanka are worst affected.

Land mines are cleared by explosives experts who put a stick in the ground
to locate them, or they use remote devices or sniffer dogs, which are all
costly and dangerous processes that typically involve a random check of just
a fraction of the area . If the genetically engineered tobacco plants prove
successful, they would offer a simple way to assess an entire field.

Aresa has already developed its ?RedDetect? technology in a weed called
Thales cress, which turns from green to autumnal red when it detects
nitrogen dioxide leaching from mines buried in the soil.

However, scientists realised the Thales cress would not be practical because
it was too small to be spotted easily from a distance, said Stellenbosch
researcher Estelle Kempen.

Aresa has now turned its sights on tobacco, which grows easily in most parts
of the world.

Field trials are already under way in Serbia, and researchers from
Stellenbosch have applied to the registrar of the Genetically Modified
Organisms Act for permission to conduct similar research.

Scientists want to assess how the genetically engineered tobacco responds to
drought and extreme temperatures, Kempen said.

The trials, if approved, would be conducted at the Welgevallen experimental
farm on the outskirts of Stellenbosch. The plants would be analysed and
destroyed before they began flowering to minimise the risk of environmental
contamination, she said.

The plant would be used solely for humanitarian purposes, and there were no
plans to seek a commercial permit.

Tobacco plants usually only produce red plant pigments in their flowers,
which arises from a natural compound called anthocyanin, which is found in
fruit such as apples and tomatoes. The technology developed by Aresa
activates anthocyanin in the tobacco plant?s leaves if there is soil
contamination from explosives such as land mines.

www.checkbiotech.org