1. UV-B Radiation, Poplar Phytochemistry & Herbivory Jeffrey M. Warren John H. Bassman Washington State University EPA STAR Graduate Fellowship Program

2. Ultraviolet Radiation Ozone Loss UV-B Radiation Increase Chromophores Phenolics, proteins, DNA Effects Direct versus indirect

3. Effects of UV-B Radiation

4. Objectives Identify effects of enhanced UV-B radiation on Populus tricocarpa foliar biochemistry: PS, chlorophylls, flavonoids, nutrients, tannin Do these UV-B induced changes affect Chrysomela scripta herbivory: Growth rate, preference

5. Methodology - UV-B Lamps Enhanced UV-B lamp systems Indoor non-modulated, Outdoor modulated Indoor Study Design 3 treatments (0X, 1X, 2X UV-B for Pullman, WA) 4 blocks 4 trees/block

6. Methodology - Trees Harvest Parameters Growth, leaf area, leaf plastochron index Chemistry Photosynthesis - 14 C (30 sec pulse) Chlorophyll a, b - DMF extraction Flavonoids - HPLC (ether, EA purification) Nitrogen, Sulfur, Carbon - Combustion Tannins - CBB-BSA binding assay

7. Methodology - Insects Feeding preference trials Single beetle in petri dish with leaf disks 3 treatments, 30 reps, 24 hours Growth rate trials Recently hatched larva grown on single leaf 3 treatments, 90 reps, 2-3 weeks

15. Conclusions Increased UV-B radiation: Increased foliar nitrogen and photosynthesis Increased flavonoids but decreased tannins Increased CLB preference / CLB growth rate