Fungal Pathogens

After adult MPB dispersal, aggregating beetles attempt to colonize host pine trees with the aid of symbiotic, blue-staining fungi (from the ophiostomatoid group) that they carry with them. The beetles depend on the fungi to overcome host defenses and to unlock nutrients from the tree. The fungi rely on the beetles as vectors to move to new host trees. The combined activity of many beetles plus the pathogenic symbiotic fungi acts to kill the tree.

By comparing the difference in genome sequence, gene function and gene expression between a pathogenic sapstaining fungus that kills pine (Grosmannia/Ophiostoma clavigerum) and a saprophytic sapstaining fungus that only discolours processed softwood (but is unable to grow in living trees; for example, Ophiostoma piceae), we hope to develop a deeper understanding of the processes by which fungi colonize a host, and the genetic features that differentiate pathogenic from saprophytic life cycles. Whole genome comparative genomics, using high-throughput sequencing technology, should yield insights into how epidemic dynamics relate to genomic and phenotypic differences (e.g. pathogenicity and host specificity).