The research will study biochemical messengers in the insect (grasshopper) grazer digestive tract and test the hypothesis that as a result of herbivory, plants respond to these messengers with altered plant growth responses and productivity. The work will identify these putative messengers and to test them in plant bioassays, utilizing coleoptile responses, sorghum seedling and whole plant responses, and a grazing-sensitive grass, Pancium coloratum. The study will test whether "Epidermal Growth Factor" (EGF), a peptidal growth factor in mammals and recently identified in grasshoppers is the messenger and whether plants have specific cell receptors to EGF. This work will provide important new information for ecological work on the relationships between plants and animals in natural and agricultural ecosystems.
