Above versus Below Ground Jasmonic Acid Induction of Arabidopsis thaliana: Glucosinolate Profiles, Fitness Costs and Transgenerational Effects

Plant defence is aiming at both above and belowground natural enemies, however, most studies thus far have considered aboveground defense in isolation. We investigated the difference between a below and above ground plant induced defence after herbivore attack by treating Arabidopsis thaliana plants with the plant hormone jasmonic acid at their roots or shoots, respectively. Treatments were performed at two different developmental stages: just before or during flowering and we measured root and shoot biomass, root and shoot glucosinolate content, seed number and seed size. Then, we used the seeds to grow a second generation plants, which received the jasmonic acid treatment as young seedlings or just before flowering. This time, we measured germination, growth curve, trichome density, glucosinolate induction, root and shoot biomass, seed number and seed size. Root versus shoot jasmonic acid induction resulted in different glucosinolate profiles, fitness costs and transgenerational consequences. Our data show that root and shoot herbivory may cause different defence expressions and different growth and fitness consequences.