Team:Toulouse/Project/Overview

Southern France is well known, among other things, for the gorgeousness of its landscapes. Plane trees (Platanus sp.) are widely present and participate to the charm of this region, especially along the famous “Canal du Midi”. This masterpiece, listed as UNESCO World Heritage, is unimaginable without its trees. Unfortunately, these trees are threatened by a severe fungal infection called Canker, and today the only treatment consists in preventive tree-cutting which has a huge cost and implies significant ecological troubles.

Facing this emergency, the students from the iGEM team of Toulouse decided to be committed to the protection of their local heritage. Indeed, using a bacterium naturally present in the trees as a vector, our team offers an alternative solution originated from synthetic biology. Thanks to different genetic modules, the engineered bacterium called SubtiTree is first able to head towards the pathogen, then to bind to its cell wall in order to finally deliver different fungicides to save the tree from its invaders. Taking into account the ecological and ethical matters, the team thinks about how to limit the spreading of the optimized microorganism through different strategies. Although our project was born from a local problematic, it is transposable to other tree vascular diseases.

Canker is one of the most important infection caused by fungi and it particularly affects plane trees (Platanus sp.). Plane trees are widely present in Southern France and participate to the site gorgeousness. Today, the only treatment consists in preventive tree-cutting which has a huge cost and implies significant ecological troubles. Facing this emergency, our team offers an innovation alternative originated from synthetic biology.

Indeed, the aim of our project is to design an endophytic bacterium called SubtiTree which is able to detect and target the pathogen in order to deliver different fungicides to save the tree from its invaders. This project limits the spreading of our engineered bacterium in the environment by considering ecological and ethical matters.

First, the bacterium targets the fungi thanks to a chimiotactism module which recognizes the soluble chitin monomers (N-acetyl-glucosamine).

Then, SubtiTree binds onto the pathogen by a chimeric protein anchored on one side to the bacterium pepdidoglycan and on the other side to the fungal chitin-based wall.

To finish, our designed bacterium fights against the pathogen by setting up a powerful treatment based on the production of three different fungicides.

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