Team:KU Leuven/Project/StickerSystem

Our initial system for the production of methylsalicylate and β-farnesene relied on direct interaction between the bacterium (BanAphids) and the aphid. This is ethically challenging since our BanAphids could end up in the environment. We therefore designed an alternative pheromone production system, whereby the bacteria are kept in semi-permeable pouches. These allow the pheromones to disperse in the air yet the bacteria themselves remain in the bags. In such a system bacteria have limited interactions with their environment. Consequently, honeydew would not touch the bacteria and cannot be used as a trigger, thus we have to adapt our pheromone expression system to these novel conditions. Our solution is an autonomous system. In its simplest form, this would be the constitutive expression of both pheromones. However, the constitutive production of β-farnesene rapidly renders aphids insensitive (Kunert, Reinhold and Gershenzon, 2010). The constant production of methyl-salicylate could be equally disadvantageous since ladybugs may become insensitive to the pheromone and the plant itself may end up in defence-mode too long, causing it to wilt. To prevent habituation β-farnesene en methyl-salicylate should fluctuate. This is typically achieved in an oscillator. Here we will concentrate on the modelling of a β-farnesene oscillator as a proof of principle. The production of methylsalicylate can be regulated similarly.