Team:KU Leuven

Since the world population keeps on growing and all people need to be fed, it’s important that crop yields are optimized. Different factors ranging from weather to diseases and pests have a huge impact on food suppliess worldwide. An example of one of these factors are aphid pests, these can lead to yield losses worth millions of dollars! Aphids, little insects belonging to the family of Aphididae, can be found everywhere: ranging from crop fields to fruit trees and even in vegetable and flower gardens. Farmers try to control them by using insecticides, but these harm the environment and aphids can become resistant to them quite rapidly. This is why we, the KU Leuven iGEM 2013 team, created an ecological insecticide-free aphid controlling mechanism, which mimics natural signalling systems used by both plants and insects.
Our bacterium is called E. coligy and produces two pheromones. The first one is methyl salicylate, which plays a role in a plant’s defence response and is produced by the plant upon infestation. The second pheromone is β-farnesene, which is an aphid alarm pheromone. In our system E. coligy produces β-farnesene to repel aphids, while the methyl-salicylate is meant to attract their natural predators such as ladybugs. We proved the functionality of these pheromones by performing insect experiments at two companies, Biobest and PC Fruit. Both companies were very interested in the concept of our project.
We designed two systems in which E. coligy can be incorporated. In the first system bacteria are sprayed on the plants and in this case the production of pheromones is dependent on the presence of aphids. This system avoids the habituation of aphids by only becoming active in the presence of aphids. The second system consists of a sticker containing E. coligy, that can be attached to a plant. In this system the production of both pheromones is alternated by the use of our own designed oscillating system. This oscillator was very extensively modelled by our team.
Since E. coligy will be introduced in the environment, the ethical aspect of our project may not be underestimated. Therefore a philosophy student joined our team to study the link between ethics and synthetic biology. He did this by interviewing the complete team in order to clarify our ethical believes and its relation to synthetic biology, by organizing a lecture with Hub Zwart (a Dutch philosopher focusing on science). We also organized a symposium to inform the general public about the ethical aspects of our project and to open discussion. After inviting our neighbouring Benelux teams, some other iGEM-teams participated. Furthermore we wrote an ethical evaluation of our project. Another way by which we have involved the public is by interviewing farmers to ask if they would use E. coligy and by going to schools with our own designed 3D-bacterium and biobricks to let students take their first steps in the fascinating world of synthetic biology.