Eurydema oleracea-induced Volatile Organic Compounds modulate Arabidopsis response to Botrytis cinerea infection

Volatile organic compounds (VOCs) are secondary metabolites through which plants interact with the environment. Upon interaction with a stressor, a blend of plant VOC changes for an increasing amount of constitutive phytochemicals and/or for phytochemicals synthesized de novo. These latter compounds are referred as induced-VOCs. We previously showed that, on Arabidopsis thaliana Col-0 plants, VOCs blend induced via jasmonic acid-related pathway by pre-inoculation with the necrotrophic fungal pathogen Botrytis cinerea significantly reduced both plant choice and feeding damage related to the piercing sucking insect Eurydema oleracea infestation. Continuing to study the same tripartite combination, we here demonstrated that VOCs released by Arabidopsis immediately after E. oleracea infestation directly inhibited the in vitro growth of B. cinerea and indirectly reduced leaf damage caused by the pathogen, triggering the jasmonic acid-mediated pathway. Insect priming of defence against B. cinerea was short-term. Together with our previous findings, this study contributes to the knowledge on the tripartite plant-microbe-insect interaction and on the role of VOCs in the communication between plants and the other organisms of a natural community.