Mechanisms and consequences of microbial induced resistance on trophic interactions and biocontrol efficacy

Beneficial microorganisms can colonize the rhizosphere of plants and modulate plant defense mechanisms against insect pests. Our knowledge of the effects of such microbial induced resistance (MIR) is limited to short time periods and direct plant defense. As MIR impacts plant physiology, it likely affects the communication between the plant and natural enemies through emission of volatile organic compounds (VOCs) over short and long terms. At longer terms, adaptation of pests to MIR may affect interactions between pests and natural enemies. We investigate the direct effects of MIR on aphid populations feeding on sweet pepper plants expressing MIR, as well as the consequences on trophic interactions and biocontrol efficacy.

The project is a collaboration between the Department of Plant and Environmental Sciences at the University of Copenhagen, with Nicolai Vitt Meyling as overall project lead, and the Department of Plant Protection Biology at SLU Alnarp, with Paul G. Becher leading the SLU part. The project involves PhD candidate Martin Nihlmar (UCPH) and postdoc Corentin Clavé (SLU).

At SLU we investigate the VOC profiles of plants with/without MIR and effects on aphids and hoverflies as their natural enemies to evaluate how MIR affects plant-insect communication at higher trophic levels. By bridging plant-microbe-insect interactions with chemical ecology in a trophic network approach, the project contributes to our understanding of the full potential of beneficial microbes in plant production.