Identification and Characterisation of Aphid and Plant Determinants of Host Range

Aphids are phloem-feeding insects that induce extensive feeding damage, achieve high population densities, and transmit economically important plant viruses to many crops worldwide. Interestingly, most aphid species are restricted to one or few host plants. However, some species, many of which are of agricultural importance, can infest a wide range of plant species. An important observation is that aphids spend a considerable time on nonhost plants, where they probe the leaf tissue and secrete saliva, but for unknown reasons are unable to ingest phloem sap. These findings suggest that aphids, like plant pathogens, interact with nonhost plants at the molecular level, but potentially are not successful in suppressing plant defenses and/or releasing nutrients. Currently there is a lack of knowledge on the plant cellular changes and the involvement of immune response, such as ETI and PTI, in aphid-host and -nonhost interactions. Our research question of interest is therefore: What biochemical, metabolic and signaling pathways do aphids target and how does this impact host range?

This specific project will involve identification and characterization of plant genes that are induced during aphid- host and nonhost interactions to gain insight into molecular mechanisms underlying aphid host range. In addition this project will involve the identification and characterization of aphid genes predicted to be involved in determining aphid host range.