Team:KU Leuven

Since the world population keeps on growing and all people need to be fed, it’s important that crop yields are optimised. Different factors ranging from weather to diseases and pests have a huge impact on food supplies worldwide. An example of one of these factors are aphid pests, these can lead to yield losses worth hundreds of millions of euros! Aphids leech on plants 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 readily. 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.

The Project

Our bacteria are called BanAphids and produce 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 the BanAphids produce β-farnesene to repel aphids, while the methyl salicylate is meant to attract their natural predators such as ladybugs. In order to provide a proof of principle we contacted two companies, Biobest and PC Fruit, where we showed the functionality of these pheromones by performing insect experiments. Both companies were very interested saw our project as a promising alternative solution.
We designed two systems to achieve our BanAphids. 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 BanAphids, that can be attached to a plant. In this system the production of the pheromones is alternated by the use of our own designed oscillating system. This oscillator was extensively modelled by our team.

Human Practices & Outreach

Since BanAphids will be introduced in the environment, the ethical aspect of our project cannot be underestimated. Therefore a philosophy student joined our team to examine the link between ethics and synthetic biology. He formulated new approaches to ethical and philosophical considerations. Together with one of our advisors he kept a blog about his impressions of the project. He took interviews of the complete team and our supervisors, to clarify our ethical beliefs and how they impact our work in synthetic biology. We organised a lecture by and a seminar with professor Hub Zwart (a Dutch philosopher focusing on science) and used his psychoanalytical reading of synthetic biology to explain the current practices in research laboratories nowadays. Next to that, the thinking of two philosophers, Hannah Arendt and Hans Jonas, was critically read and taken into synthetic biology to see whether the concepts they use are useful to evaluate synthetic biology. Finally, we wrote an normative evaluation of our project against the background of current literature on ethics and synthetic biology.
We organised a symposium and a debate to inform the general public about our project and to open the discussion on the ethical aspects. We invited our neighbouring Benelux iGEM teams for both events. Some Benelux iGEM-teams participated this year so we are now contemplating a "Benelux-GEM slam" for the future. We also went out on the street and interviewed farmers to ask if they would use BanAphids and visited several schools with our own biobricks and 3D-bacterium design to let students take their first steps in the fascinating world of synthetic biology.