Blue stain fungus genome decoded
Researchers at the University of British Columbia have decoded the genome of the fungus that helps mountain pine beetles infect and kill lodgepole pines.
Grosmannia clavigera, also known as blue stain fungus for the stain it leaves in the wood of infected trees, is carried to the host trees by pine beetles. It weakens the tree's natural defence system, which allows pine beetles to feed and reproduce in the tree bark. A successful beetle-fungus attack ultimately causes tree death.
Researchers from UBC and the B.C. Cancer Agency's Genome Sciences Centre conducted a detailed genome analysis and identified genes in Grosmannia clavigera that are responsible for the fungus's ability to bypass the lodgepole pine's natural fungicide — and use it as a carbon source for fungal growth.
The study was published this week in the Proceedings of the National Academy of Sciences.
"Our study helps to clarify how the fungus has evolved to successfully infect lodgepole pine and gives us a better understanding of the intricate chemical interaction between the tree, beetle and fungus," said co-author Joerg Bohlmann, a professor of Forest Science and Botany at UBC.
"This new knowledge could inform strategies to prevent future outbreaks, such as selecting trees with improved resistance to pine beetles and their associated pathogens."
The researchers found that the fungus can not only survive but even thrive when exposed to the normally fungicidal resin chemicals of pines.
The current outbreak of mountain pine beetle has destroyed more than 16 million hectares of forest in British Columbia. It crossed the Rocky Mountains and is now in the boreal pine forests, moving east. The devastation of large areas of pine forest is anticipated to have major consequences for global carbon balance and sequestration.
Bohlmann, Colette Breuil, a professor in the UBC Department of Wood Science and Scott DiGuistini, a doctoral student in the UBC faculty of forestry, led the study.
The study was funded by Genome BC, Genome Alberta, Genome Canada, as well as the Natural Sciences and Engineering Research Council of Canada and the B.C. Ministry of Forests.