Project description:Collectively classified as white-rot fungi, certain basidiomycetes efficiently degrade the major structural polymers of wood cell walls. A small subset of these Agaricomycetes, exemplified by Phlebiopsis gigantea, is capable of colonizing freshly exposed conifer sapwood despite its high pitch content, which retards the establishment of other fungal species. The mechanism(s) by which P. gigantea tolerates and metabolizes resinous compounds have not been explored. Here, we report the annotated P. gigantea genome and compare profiles of its transcriptome and secretome when cultured on fresh-cut versus solvent-extracted loblolly pine. The P. gigantea genome contains a conventional repertoire of hydrolase genes involved in cellulose/hemicellulose degradation, whose patterns of expression were relatively unperturbed by the absence of extractives. The expression of genes typically ascribed to lignin degradation was also largely unaffected. In contrast, genes likely involved in the transformation and detoxification of pitch were highly induced in its presence. Their products included an ABC transporter, lipases, cytochrome P450s, glutathione S-transferase and aldehyde dehydrogenase. Other regulated genes of unknown function and several constitutively expressed genes are also likely involved in P. gigantea’s pitch metabolism. These results contribute to our fundamental understanding of conifer colonization and carbon cycling processes. Phlebiopsis gigantea was cultivated in media containing one of three carbon sources: freshly harvested loblolly pine (3 replicates), acetone extracted lobollly pine (3 replicates), or glucose (2 replicates). RNA was extracted and processed for Illumina sequencing as described below.
Project description:Collectively classified as white-rot fungi, certain basidiomycetes efficiently degrade the major structural polymers of wood cell walls. A small subset of these Agaricomycetes, exemplified by Phlebiopsis gigantea, is capable of colonizing freshly exposed conifer sapwood despite its high pitch content, which retards the establishment of other fungal species. The mechanism(s) by which P. gigantea tolerates and metabolizes resinous compounds have not been explored. Here, we report the annotated P. gigantea genome and compare profiles of its transcriptome and secretome when cultured on fresh-cut versus solvent-extracted loblolly pine. The P. gigantea genome contains a conventional repertoire of hydrolase genes involved in cellulose/hemicellulose degradation, whose patterns of expression were relatively unperturbed by the absence of extractives. The expression of genes typically ascribed to lignin degradation was also largely unaffected. In contrast, genes likely involved in the transformation and detoxification of pitch were highly induced in its presence. Their products included an ABC transporter, lipases, cytochrome P450s, glutathione S-transferase and aldehyde dehydrogenase. Other regulated genes of unknown function and several constitutively expressed genes are also likely involved in P. gigantea’s pitch metabolism. These results contribute to our fundamental understanding of conifer colonization and carbon cycling processes.
Project description:Mass spectrometric analysis of extracellular proteins in culture filtrate was performed to elucidate the mechanisms of extractive degradation by Phlebiopsis gigantea of microcrystalline cellulose coated and uncoated with an acetone extract from the Pinus taeda (loblolly pine)
Project description:Transcript profiles of H. annosum from mycelium grown on different substrates and under different stresses were analyzed. The array probes were designed from gene models taken from the Joint Genome Institute (JGI, department of energy) H. irregulare genome sequence version 1. One aim of this study was to compare gene expression profiles of H. annosum pre-grown on secondary metabolites from the biocontrol agent Phlebiopsis gigantea.
Project description:Transcript profiles of H. annosum from mycelium grown on different substrates and under different stresses were analyzed. The array probes were designed from gene models taken from the Joint Genome Institute (JGI, department of energy) H. irregulare genome sequence version 1. One aim of this study was to compare gene expression profiles of H. annosum pre-grown on secondary metabolites from the biocontrol agent Phlebiopsis gigantea. We performed six hybridizations with samples derived from H. annosum grown in either liquid Malt Extract Medium (three biological replicates) or on secondary metabolite from Phlebiopsis gigantea (three biological replicates). The Heterobasidion irregulare custom-exon expression array (4 x 72K) manufactured by Roche NimbleGen Systems Limited (Madison, WI) (http://www.nimblegen.com/products/exp/index.html) contained five independent, non-identical, 60-mer probes per gene model coding sequence. For 12,199 of the 12,299 annotated protein-coding gene models, probes could be designed. For 19 gene models, no probes could be generated, and 81 gene models shared all five probes with other gene models. Included in the array were 916 random 60-mer control probes and labelling controls. For 2032 randomly chosen gene models, technical duplicates were included on the array.