Postdoc Michigan State University East Lansing, Michigan
Abstract: Rising global temperatures are predicted to increase herbivore pressures for plants in agricultural and ecological settings. Despite considerable progress toward understanding the mechanisms mediating plant defenses, little is known about how these defenses are affected by high temperature. Plant responses to insect attack are largely regulated by the hormone jasmonate (JA) which is synthesized rapidly upon perception of insect herbivores, resulting in the deployment of chemical defenses that promote resistance to herbivory. Using tomato and Arabidopsis model systems we investigated the effects of elevated temperature on herbivore and wound-induced JA responses. Although elevated temperatures significantly accelerate feeding behaviors of the lepidopteran herbivores T. ni and M. sexta by increasing total feeding bout duration and feeding rates, no evidence for heat-induced attenuation of plant defense was detected. In both Arabidopsis and Tomato systems the accumulation of JA and JA response markers remained intact under elevated temperature. Proteomic analysis of T. ni frass suggests that an increase in the production of digestive proteins contributes to accelerated growth and host tissue consumption under elevated temperature conditions. Together our results suggest that, in the battle between herbivores and plants to eat or not be eaten, elevated temperature tips the balance in favor of herbivores.
