DIALOGUES AT THE INSECT-PLANT INTERFACE: ROLE OF SALIVARY SIGNALS

Insects secrete saliva when feeding on plants. Saliva performs multiple functions including aiding in digestion, protecting against micorbial pathogens, detoxifying plant poisons, and in some cases saliva may help insects circumvent host plant defenses. In some cases, plants are able to detect the presence of herbivores due to the damage they cause and the secretions they release. Following recognition, plants may mount formidable, induced defenses directed at the insect pests. Our reserch has uncovered several components of saliva of caterpillars that are recognized by the tomato plant and result in turning on these plant defenses. Our project aims to characterize the protein components of saliva responsible for induction, identify and sequence the genes responsible for their production, and conduct a comprehensive study of the function of the genes. This research will help identify some of the mechanisms employed by the tomato fruitworm, Helicoverpa zea, that have contributed to its status as one of the most important agricultural pests in the New World. The research may also aid in the discovery of novel approaches towards developing resistant host plants targeted towards this serious pest. A long term goal would be to develop plants that can specifically "recognize" this pest and turn on the appropriate defenses. Such an approach could provide an environmentally safe alternative to synthetic approaches and provide for a more sustainable approach to pest management.