Transcriptomic and proteomic analysis of Trametes versicolor interacting with a Hypholoma fasciculare mycelium foraging in soil

The decomposition of large woody material is an important process in forest carbon cycling and nutrient release. Cord-forming saprotrophic basidiomycete fungi create non-resource limited mycelial networks between decomposing branches, logs and tree stumps on the forest floor where colonisation of new resource is often associated with the replacement of incumbent decay communities. Cord-forming species often dominate competition hierarchies in controlled paired antagonism experiments and have been shown to translocate resource to support colonisation and produce inhibitory metabolites. To date, antagonism experiments have mostly placed competing fungi in direct contact, while in nature cord-forming saprobes encounter colonised wood as mycelia in a network. Here we used soil-based microcosms that allowed foraging cord-forming Hypholoma fasciculare to encounter a wood block colonised by Trametes versicolor and conducted transcriptomic and proteomic analysis of the interaction. Cellular processes and metabolic responses to the competitive interaction were identified, where protein turnover featured strongly for both species. H. fasciculare demonstrated an exploitative profile with increased transcription of enzymes that targeted carbohydrate polymers of the substrate and in RNA and ribosome processing. T. versicolor showed a shift in signalling, energy generation and amino acid metabolism. Putative genes involved in secondary metabolite production were identified in both species. This study highlights the importance of ecologically-relevant experimental design when considering complex processes such as community development during wood decomposition Overall design: Beechwood microcosms were established with laboratory cultures of Hypholoma fasciculare and Trametes versicolor and species interactions conducted with single species controls We conducted RNA-seq analysis using an Illumina HiSeq2500 on three replicates of H. fasciculare-T. versicolor interaction and three repicates of a single species control for each species at 14 h postcontact between the species Comparative gene expression profiling analysis of RNA-seq data for interaction samples and singel speceis controls