Impacts of Climate Change on Herbivore Induced Plant Signaling and Defenses

The accumulation of CO2 and O3 in the troposphere alters phytochemistry which in turn influences the interactions between plants and insects. Using microarray analysis of field-grown soybean (Glycine max), we found that the number of transcripts in the leaves affected by herbivory by Japanese beetles (Popillia japonica) was greater when plants were grown under elevated CO2, elevated O3 and the combination of elevated CO2 plus elevated O3 than when grown in ambient atmosphere. The effect of herbivory on transcription diminished strongly with time (<1% of genes were affected by herbivory after 3 weeks), and elevated CO2 interacted more strongly with herbivory than elevated O3. The majority of transcripts affected by elevated O3 were related to antioxidant metabolism. Constitutive levels and the induction by herbivory of key 1 This chapter was published in Plant, Cell & Environment in 2008. Casteel CL, O'Neill BF, Zavala JA, Bilgin DD, Casteel CL, Berenbaum MR, DeLucia EH (2008) Transcriptional profiling reveals elevated CO2 and elevated O3 alter resistance of soybean (Glycine max) to Japanese beetles (Popillia japonica). Plant Cell and Environment 31: 419-434 Author contributions: the research was designed by Clare L. Casteel, May R. Berenbaum, and Evan H. DeLucia. Damla Bilgin, Jorge Zavala, Bridget O‘ Neill and Clare L. Casteel collected data; Clare L. Casteel performed all other research. The paper was written by Clare L. Casteel while being advised by May R. Berenbaum and Evan H. DeLucia.