Project Number: 6217-21000-007-07
Project Type: Specific Cooperative Agreement

Start Date: Aug 01, 2006
End Date: Jul 31, 2011

Objective:
Plant-insect interaction is complex and dynamic; however, little is known about the molecular basis of plant defense against insect pests. The research objectives of this project are to explore the diversity of host responses to aphid attack and to gain a better understanding of the mechanisms underlying the interactions between host plants and phloem-feeding insects. In this project, host plants and attacking aphids will be studied simultaneously using genetic and functional genomics tools, which will lead to the identification of virulence factors of the pest aphids and novel resistance genes of host plants, and reveal important mechanisms that mediate direct and indirect defenses. It is anticipated that information obtained from these studies, based on the combined knowledge of the defense systems operating in the plants and the attacking systems used by pests, will contribute to the development of crop plants with durable and multi-mechanistic resistance to insect pests.

Approach:
In this project, sorghum plant and phloem-feeding aphids will be used as the model system to study plant-insect interaction, which may extend to functional genomic studies in other crop species. Insect attack elicits a large transcriptional reorganization leading to activation of host defense. Elicitors in the aphid oral secretions can account for aphid-specific responses. Thus, genome-wide gene expression profiling will be conducted to identify candidate genes potentially responsible for induced plant defense against aphid pests. Subsequently, genetic and molecular tools are used to define the function of those newly identified genes and the gene products in host defense.