Heterobasidion annosum s.l. causes a devastating root rot in conifer plantations and natural forests throughout the northern hemisphere. The proposed genome sequencing for H. annosum will provide the first comprehensive genetic information on a plant pathogenic homobasidiomycete allowing for new insights into plant-microbe interactions with trees, in particular conifers. It is important to broaden the taxonomic base for understanding the mechanisms of plant-microbe interactions, studying genes and proteins involved, and identifying pathogenicity determinants. Comparative genomics of plant pathogens with a gradient of taxonomic relatedness to H. annosum will help to understand the evolution of such factors.

Comparisons can also be made in the response of plants to various types of trophic interactions. Interactions with the necrotrophic pathogen H. annosum and the model tree Populus can be compared to biotrophic interactions with rust pathogen fungi and mycorrhizal mutualists. This will increase the information on comparative genomics on fungi in general and to develop a broader view on the complex communities associated with the model tree Populus.
The sequence information will enable a comparison with the model white rotter Phanerochaete chrysosporium, deepening our understanding of wood degradation including ligninolytic and polysaccharide degradation pathways as well as for several bioremediation applications where the oxidative systems of white rotting basidiomycetes can be used to detoxify organic pollutants.

Moreover, this project will also gain insights into fungal evolutionary history and biology including development, non self recognition, mating, and secondary metabolism.

Recent progress in the H. annosum research include: Possibilities for fruiting and classical genetics, publication of a genetic linkage map, EST compilation of more than 3000 seqences is available, transformation system, knowledge of genetics of interspecific recognition, phylogeny of the species complex, pathogenicity factors in nucleus and mitochondria etc. This allows for a direct use of sequence information for gene discovery and functional analysis.