Arabidopsis thaliana plants produce beta-cyclocitral when attacked by herbivores. This volatile signal inhibits the MEP pathway is instrumental in plant growth processes, such as the production of pigments for photosynthesis. Since the MEP pathway is only found in plants and microorganisms, but not animals, knowledge of a signal molecule like beta-cyclocitral opens up new possibilities for the development of herbicides or antimicrobial agents that block this pathway.