This award is for a international collaborative research project involving the laboratories of Georg Jander at the Boyce Thompson Institute in Ithaca, New York, and Jonathan Gershenzon at the Max Planck Institute for Chemical Ecology in Jena, Germany, which both study plant-insect interactions using the small crucifer plant Arabadopsis thaliana as a model system. One area of common research interest that will be explored is the glucosinolate/myrosinase system, which is a characteristic insect defense of crucifers. Upon herbivore damage, glucosinolate molecules are cleaved by the enzyme myrosinase to produce a variety of sharp-tasting and sometimes volatile compounds that deter insect feeding. Although the general mechanism of the glucosinolate/myrosinase system is known, many details about the role of individual glucosinolates, myrosinases, and accessory enzymes in insect defense remain uninvestigated. The proposed research combines plant mutants and insect behavior assays developed in the Jander laboratory with biochemical assays for the detection of plant volatiles, which have been developed in the Gershenzon laboratory, to answer specific questions related to insect defense in A. thaliana: 1. What are the enzymatic specificities of the two A. thaliana myrosinase enzymes? 2. What is the time-course of glucosinolate breakdown during Myzus persicae (green peach aphid) feeding on A. thaliana? 3. What plant-derived volatiles are produced by A. thaliana in response to M. persicae feeding?
The proposed collaboration between the Jander and Gershenzon laboratories will use complementary research approaches to achieve common scientific goals. Already established molecular and chemical ecology research programs at the two institutions will benefit from this interaction and exchange of ideas. Students and postdocs from the Jander laboratory will have the opportunity to perform experiments at the Max Planck Institute and will benefit from an international research experience in Germany. Joint research efforts that will be initiated through this proposal are likely to extend beyond the end of the funding period. Research using the A. thaliana . M. persicae model system will lead to new insights into plant defense against phloem-feeding insects, which has received relatively little attention compared to that directed against chewing insects and microbial pathogens. M. persicae, the insect model used in the proposed experiments, is a common crop plant pest and the most prolific transmitter of viral diseases of dicotyledonous crop plants worldwide. A better understanding of plant-insect interactions in general and, more specifically, defense against M. persicae will lead to the development of new strategies for crop plant protection and genetic improvement.
