Project description:Lignin is a biopolymer found in plant cell walls that accounts for 30% of the organic carbon in the biosphere. White-rot fungi (WRF) are considered the most efficient organisms at degrading lignin in Nature. While lignin depolymerization by WRF has been exhaustively studied, the possibility that WRF are able to utilize lignin as a carbon source is still a matter of controversy. Here we employ 13C-labeling and systems biology approaches to demonstrate that two WRF, Trametes versicolor and Gelatoporia subvermispora, funnel lignin-derived aromatic compounds into central carbon metabolism via intracellular catabolic pathways. These results provide insights into global carbon cycling in soil ecosystems, and furthermore establishes a foundation for employing WRF in simultaneous lignin depolymerization and bioconversion to bioproducts – a key step towards enabling a sustainable bioeconomy.
Project description:To determine the wood degradation mechanism and its key genes of Lenzites gibbosa, we sequenced 15 transcriptomes of mycelial samples under woody environments at 3, 5, 7, and 11 d (D3, D5, D7, and D11) and non-woody environments (CK). All the transcripts were annotated as much as possible in eight databases to determine their function. The key genes and biological processes, relating to wood degradation, were predicted and screened. A total of 2069 differentially expressed genes (DEGs) were obtained in ten differential groups. Comparing wood with non-wood treatment conditions, the key genes were those participating in oxidation-reduction process, they were oxidoreductases and peroxidases genes, and their regulators genes; these genes mainly focused on the three biological processes of carbohydrate metabolism, lignin catabolism, and secondary metabolites biosynthesis, transport and catabolism. The mostly enriched subcategories in molecular function were oxidoreductase activity, peroxidase activity, and heme binding in GO annotation. One cellulose and hemicellulose degradation pathway and seven pathways related to lignin-derived aromatic compounds degradation or late lignin degradation were found. In conclusion, during the process of L. gibbosa growing on wood, gene expression at the transcriptional level indicated that lignin catabolism and hyphal growth were promoted, but the metabolism of carbon and carbohydrates including cellulose in lignocellulose in overall trend was inhibited to some extent. The results have important reference value for the study of degradation mechanism of wood white rot.
Project description:White-rot fungi (WRF), considered the most efficient organisms at degrading organic carbon in the biosphere, are found in plant cell wall lignin biopolymer. We employ multi-omics to demonstrate that Trametes versicolor and Gelatoporia subvermispora funnel lignin-derived aromatic compounds into central carbon metabolism via intracellular catabolic pathways. These results provide insights into global carbon cycling in soil ecosystems.
