Whether they are suffering from a lack of water or minerals, an attack by pathogens or insect pests, plants emit odorous molecules. Some of these volatile substances activate an internal defence mechanism. Others, released in the atmosphere or in the soil, have the effect of attracting the natural enemies' herbivores in order to protect the plant.

The researchers in this project are mainly interested in the defence mechanisms in the root zone of maize and in identifying the odorous molecules involved as well as the genes that control their production. For example, as a way to protect itself from the western corn rootworm Diabrotica, maize roots emit an odorous signal attractive to tiny nematodes that will infect and kill the insect pest.

Certain American varieties have lost this signalling ability over the course of selective breeding. By restoring the odorous signal in these varieties they may regain their original defence mechanisms. A better understanding of the activated genes, the substances produced and of the reactions they trigger contribute to the development of novel and ecologically sound biological control strategies.