Early Stage Infection-Specific Heterobasidion annosum (Fr.) Bref. Transcripts in the H. annosum – Pinus sylvestris L. Pathosystem

Transcriptomes from stem-inoculated Scots pine saplings were analyzed to identify unique and enriched H. annosum transcripts in the early stages of infection. Comparing different time points since inoculation identified 131 differentially expressed H. annosum gene with p values ≤ 0.01. Our research supports the results of previous studies on the Norway spruce – Heterobasidion annosum s.l. pathosystem, indicating the role of carbohydrate- and lignin degradation genes in pathogenesis at different timepoints post inoculation and the role of lipid metabolism genes (including but not limited to the delta-12 fatty acid desaturase gene previously reported to be an important factor). The results of this study indicate that malic enzyme could be a potential gene of interest in the context of H. annosum virulence.