Go to our new-look site, it combines the Biotechnology and Science Learning Hubs with a new look and new functionality. This is our legacy site and is no longer maintained.

Skip to page content

Site navigation

The smell of genetically modified fear

29 May, 2012

A group of British scientists have begun a field trial after successfully genetically modifying wheat to repel aphid pests.

Peppermint plant gene added to wheat

The scientists, from the Rothamsted Research Station, have added a peppermint plant gene to wheat, allowing the wheat to emit an alarm pheromone that aphids associate with danger.

The pheromone, E-beta-Farnesene, is naturally produced by peppermint to mimic the same pheromone released by aphids as a distress signal to warn other aphids when they come under attack from predators.

Peppermint pheromone tricks aphids

Not only are the aphids tricked into staying away from the crop, but as an added bonus, the smell also attracts some of their predators, in particular, a parasitic wasp and ladybugs. Fortunately, the smell is too mild to be detected by humans so there won’t be any funny tasting bread if the variety is ever commercially available.

First GM crop to repel insects

The wheat is believed to be the world’s first GM crop that repels insects instead of killing them, reducing the chances of the pests developing immunity to it. The variety should also reduce the need to spray with toxic pesticides.

Aphids are a major pest problem for cereal crops, causing NZ$238m worth of crop damage every year in the UK alone. This figure does not include the millions spent on pesticides to combat the aphids.

Pest control that doesn’t require toxic pesticides

Project leader Professor John Pickett is widely quoted as saying, “… we are providing a new way of controlling the pests that doesn’t rely on toxic modes of action. We believe in the long term all crops need to be protected through the genetics in the seed.”

Professor Maurice Moloney, director of Rothamsted Research, says that usually genetic modification has been used so that you’ve got to kill something. “In this case, what we are really doing is putting a no-parking zone on the leaf of the plant saying ‘don’t come here’.”


Return to top