UPSC Seminar Series 2015
Speaker:
Janice Cooke
Department of Biological Sciences
University of Alberta, Edmonton, Canada
Title: Living on the edge: Responses of an evolutionarily co-evolved and a naïve
pine host in the face of mountain pine beetle range expansion
Host. Ulrika Ganeteg
Room: Lilla hörsalen, KB3A9
Abstract:
The current epidemic of mountain pine beetle (MPB) has impacted more than
28 million hectares of pine forests in western North America. Lodgepole
pine, with a range overlapping that of MPB, has been the main species of
pine affected by the present outbreak. From its historic range in British
Columbia, MPB has spread across the Rocky Mountains into northern Alberta.
In this novel habitat, lodgepole pine hybridizes with jack pine, a boreal
forest species. We used species-distinguishing markers to refine this
hybrid zone, and demonstrate that MPB has undergone host range expansion
to pure jack pine. We are testing the hypotheses that (1) host quality
differs between lodgepole and jack pine and (2) that abiotic stresses such
as water limitation affect these responses. Lesion development following
inoculation with the MPB fungal associate Grosmannia clavigera was slower
in jack pine than lodgepole pine, with water deficit delaying lesion
development in both species. G. clavigera inoculation significantly
increased levels of jasmonic acid in both species. Microarray analyses
revealed that thousands of genes are invoked in the response of these pine
species to G. clavigera infection, that there are substantial differences
in responses of lodgepole and jack pine, and that water limitation alters
this transcriptional programme.