Project description:AIM: By adopting comparative transcriptomic approach, we investigated the gene expression of wood decomposing Basidiomycota fungus Phlebia radiata. Our aim was to reveal how hypoxia and lignocellulose structure affect primary metabolism and the expression of wood decomposition related genes. RESULTS: Hypoxia was a major regulator for intracellular metabolism and extracellular enzymatic degradation of wood polysaccharides by the fungus. Our results manifest how oxygen depletion affects not only over 200 genes of fungal primary metabolism but also plays central role in regulation of secreted CAZyme (carbohydrate-active enzyme) encoding genes. Based on these findings, we present a hypoxia-response mechanism in wood-decaying fungi divergent from the regulation described for Ascomycota fermenting yeasts and animal-pathogenic species of Basidiomycota.
Project description:White-rot basidiomycete fungi are potent degraders of plant biomass with the ability to mineralize all lignocellulose components. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. Deeper functional analyses are however necessary to understand the enzymatic mechanisms leading to lignocellulose breakdown. The Polyporale fungus Pycnoporus coccineus CIRM-BRFM310 grows well on both coniferous and deciduous wood. In the present study we analyzed the early response of the fungus to softwood (pine) and hardwood (aspen) feedstocks.
Project description:White-rot basidiomycete fungi are potent degraders of plant biomass with the ability to mineralize all lignocellulose components. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. Deeper functional analyses are however necessary to understand the enzymatic mechanisms leading to lignocellulose breakdown. In the present study we analyzed the early response of the Polyporales fungi Pycnoporus coccineus CIRM-BRFM310, Pycnoporus cinnabarinus CIRM-BRFM137 and Pycnoporus sanguineus CIRM-BRFM 1264 to various carbon sources including lignocellulosic biomass.
Project description:White-rot basidiomycete fungi are potent degraders of plant biomass with the ability to mineralize all lignocellulose components. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. Deeper functional analyses are however necessary to understand the enzymatic mechanisms leading to lignocellulose breakdown. In the present study we analyzed the early response of the Polyporales fungi Pycnoporus coccineus CIRM-BRFM310, Pycnoporus cinnabarinus CIRM-BRFM137 and Pycnoporus sanguineus CIRM-BRFM 1264 to various carbon sources including lignocellulosic biomass.
Project description:White-rot basidiomycete fungi are potent degraders of plant biomass with the ability to mineralize all lignocellulose components. Recent comparative genomics studies showed that these fungi use a wide diversity of enzymes for wood degradation. Deeper functional analyses are however necessary to understand the enzymatic mechanisms leading to lignocellulose breakdown. In the present study we analyzed the early response of the Polyporales fungi Pycnoporus coccineus CIRM-BRFM310, Pycnoporus cinnabarinus CIRM-BRFM137 and Pycnoporus sanguineus CIRM-BRFM 1264 to various carbon sources including lignocellulosic biomass.
Project description:Agaricomycetes produce the most efficient enzyme systems to degrade wood and the most complex morphological structures in the fungal kingdom. Despite decades-long interest in their genetic bases, the evolution and functional diversity of both wood-decay and fruiting body formation are incompletely known.Here, we perform comparative genomic and transcriptomic analyses of wood-decay and fruiting body development in Auriculariopsis ampla and Schizophyllum commune (Schizophyllaceae), species with secondarily simplified morphologies and enigmatic wood-decay strategy and weak pathogenicity to woody plants. The plant cell wall degrading enzyme repertoires of Schizophyllaceae are transitional between those of white rot species and less efficient wood-degraders such as brown rot or mycorrhizal fungi. Rich repertoires of suberinase and tannase genes were found in both species, with tannases restricted to Agaricomycetes that preferentially colonize bark-covered wood, suggesting potential complementation of their weaker wood-decaying abilities and adaptations to wood colonization through the bark. Fruiting body transcriptomes of A. ampla and S. commune revealed a high rate of divergence in developmental gene expression, but also several genes with conserved developmental expression, including novel transcription factors and small-secreted proteins, some of the latter might represent fruiting body effectors. Taken together, our analyses highlighted novel aspects of wood-decay and fruiting body development in a widely distributed family of mushroom-forming fungi.
Project description:Wood-degrading fungi vary in their strategies for deconstructing wood, and their competitive successes shape the rate and fate of carbon released from wood, Earth’s largest pool of aboveground terrestrial carbon. In this study, one-on-one interspecific interactions between two model brown rot (carbohydrate-selective) fungi, Gloeophyllum trabeum and Rhodonia (Postia) placenta, were studied on wood wafers where a clearly resolved interaction zone (IZ) could be generated, reproducibly. Comparative RNAseq and proteomics between the IZ and non-interacting hyphae of each species identified combative strategies for each fungus. Glycoside hydrolases were a relatively smaller portion of the interaction secretome compared to non-interacting hyphae. The interaction zone showed higher pectinase specific activity than all other sampling locations, and higher laminarinase specific activity (branched β‐glucan proxy) was seen in the IZ secretome relative to equivalent hyphae in single‐species cultures. Our efforts also identified two distinct competitive strategies in these two fungi with a shared nutritional mode (brown rot) but polyphyletic ancestral lineages. Gloeophyllum trabeum (Gloeophyllum clade) employed secondary metabolite (SM) synthesis in response to a competitor, as shown by the upregulation of several SM-synthesizing genes in the interaction. R. placenta (Antrodia clade) instead upregulated a larger variety of uncharacterized oxidoreductases in interacting hyphae, suggesting that an oxidative burst may be a response to competitors in this fungus. Both species produced several hypothetical proteins exclusively in the interaction zone, leaving abundant unknowns on the battlefield. This work supports the existence of multiple interaction strategies among brown rot fungi and highlights the functional diversity among wood decay fungi.
2020-05-22 | GSE151023 | GEO
Project description:Succession of fungi in decomposing beech and fir wood
Project description:Brown rot fungi have great potential in biorefinery wood conversion systems, because they are the primary wood decomposers in coniferous forests and have an efficient lignocellulose degrading system. Their initial wood degradation mechanism is thought to consist of an oxidative radical-based system that acts sequentially with an enzymatic saccharification system, but the complete molecular mechanism of this system has not yet been elucidated. Some studies have shown that wood degradation mechanisms of brown rot fungi have diversity in their substrate selectivity. Gloeophyllum trabeum, one of the most studied brown rot species, has broad substrate selectivity and even can degrade some grasses. However, the basis for this broad substrate specificity is poorly understood. In this study, we performed RNA-seq analyses on G. trabeum grown on media containing glucose, cellulose, or Japanese cedar (Cryptomeria japonica) as the sole carbon source. Beyond the gene expression on glucose, 1129 genes were upregulated on cellulose and 1516 genes were upregulated on cedar. Carbohydrate Active enZyme (CAZyme) genes upregulated on cellulose and cedar media by G. trabeum included GH12, GH131, CE1, AA3_1, AA3_2, AA3_4 and AA9, which is a newly reported expression pattern for brown rot fungi. The upregulation of both terpene synthase and cytochrome P450 genes on cedar media suggests the potential importance of these genes in the production of secondary metabolites associated with the chelator-mediated Fenton reaction. These results provide new insights into the inherent wood degradation mechanism of G. trabeum and the diversity of brown rot mechanisms.