Project Description:

Long-term goal is to develop maize (Zea mays L.) cultivars with improved host plant resistance against root feeding by larvae of the western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte), the most important insect pest in the U.S. Cornbelt.

However no germplasm sources with superior WCR resistance are known. Along with the lack of highly resistant maize cultivars, only limited information is available about the organized defense responses of maize against root feeding and wounding. To overcome these obstacles researchers will investigate the genetic and biochemical basis of the defense response in maize against the WCR and develop material that allows for mapping of the resistance traits.

The integration of different approaches, i.e., phenotypic characterization, selection, genomics, and metabolomics, will be of key importance to first understand how plant and insect interact. This knowledge and the genetic basis of the trait(s) are also key requisites if one wishes to increase the effectiveness of screening maize germplasm for novel WCR resistance sources and to devise new methods to integrate this germplasm into elite breeding programs in the Midwestern Cornbelt.

Supporting Objectives

The project has the following technical objectives and underlying hypothses:

Objective 1: Monitor and understand responses of maize cultivars by a hypothesis driven analysis of differential gene expression patterns in the presence and absence of WCR larvae.

Output 1: Information on (putative) signal transduction, gene induction, proteins and biochemical defense pathways and genes differentially expressed in maize roots

Impact 1: The use of microarrays, RT-PCR, and appropriate statistical analyses will help in verifying molecular elements and the genetic foundation of maize-WCR interactions.

Objective 2: Anaylyze the root 'defense proteome and metabolome' of maize cultivars in the presence of WCR larvae

Output 2: Metabolite and protein profiles, their dynamic changes upon insect feeding and their correlation with genetic and molecular characters in maize cultivars.

Impact 2: A catalog of metabolites and proteins that records the impact of WCR feeding on plant metabolism will identify the compounds that distinguish resistant/tolerant or susceptible maize inbreds. In the long-term this will lead to predictive assessment of the metabolic pathways and metabolites that deter or encourage feeding by WCR larvae.

If interested in the details of this project, please contact the investigators for a copy of the complete proposal.