Data from: Soil microbes alter herbivore-induced volatile emissions in response to cereal cropping systems

Soil microbes can influence the emissions of plant volatile organic
compounds (VOCs), which serve as host-location cues for insect pests and
their natural enemies. Agricultural practices steer unique soil microbial
communities, but how this influences crop VOCs and subsequent insect
attraction remains unknown. The aim of this study was to investigate the
effect of diversified agricultural practices on constitutive and
herbivore-induced VOC emissions by crops through soil-microbe legacy
effects. In a full factorial experiment, we measured VOC emissions by
wheat (Triticum aestivum) grown in soil inoculum from wheat-fallow or
wheat-cover crop rotations that was subjected to larval feeding by
sawflies (Cephus cinctus). Under herbivory, plants grown in cover crop
inoculum emitted greater total VOCs, including higher concentrations of
2-pentadecanone, a known insect repellent, and nonanal, a compound
important in the recruitment of natural enemies of pests. Plants grown in
fallow inoculum showed no differences in VOC emissions whether under
herbivory or not. Soil inoculum did not influence VOC emissions of plants
in the absence of larval feeding. These results suggest that agricultural
practices influence crop VOC emissions through microbe-mediated soil
effects. Additionally, crops grown in wheat-fallow rotations may be less
successful recruiting natural enemies of pests through herbivore-induced
VOC signaling.