Induction of plant volatiles by insect egg deposition on elm (Ulmus campestris): using molecular methods and genetic transformation to understand an ecological phenomenon

• Applicant: Dr. Torsten Meiners
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: from 2004 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5431310

It has been known for some years that many plants respond to herbivore feeding by releasing volatile compounds which attract enemies of the herbivores. However, there are many unanswered questions regarding the induction, regulation, specificity, and natural function of these indirect defences. We have shown recently that the European field elm (Ulmus campestris) releases volatiles in response to insect herbivores before actual herbivory has even begun, namely after egg deposition by elm leaf beetles (Xanthogaleruca luteola). Leaves in the vicinity of the deposited eggs release specific blends of mostly terpenoid volatiles, which are highly attractive to the egg parasitoid Oomyzus gallerucae. By combining methods from chemical ecology, analytical chemistry, molecular biology and plant transformation, we intend to investigate (a) the mode of volatile induction at the level of gene expression, (b) how U. campestris regulated the production of the induced volatiles on specific temporal and spatial scales, and (c) the function of the genes associated with the volatiles involved in parasitoid attraction, through the use of genetically-transformed lines of U. campestris which will be tested with the egg parasitoids in olfactometer bioassays.

• DFG Programme: Research Grants