Data from: The Paleozoic origin of enzymatic lignin decomposition reconstructed from 31 fungal genomes

Wood is a major pool of organic carbon that is highly resistant to decay, owing largely to the presence of lignin. The only organisms capable of substantial lignin decay are white rot fungi in the Agaricomycetes, which also contains non–lignin-degrading brown rot and ectomycorrhizal species. Comparative analyses of 31 fungal genomes (12 generated for this study) suggest that lignin-degrading peroxidases expanded in the lineage leading to the ancestor of the Agaricomycetes, which is reconstructed as a white rot species, and then contracted in parallel lineages leading to brown rot and mycorrhizal species. Molecular clock analyses suggest that the origin of lignin degradation might have coincided with the sharp decrease in the rate of organic carbon burial around the end of the Carboniferous period.木材是有机碳的重要储存库，其极强的抗降解性主要源于木质素(lignin)的存在。目前已知唯一能够大规模降解木质素的生物是伞菌纲(Agaricomycetes)中的白腐真菌，该类群同时包含无法降解木质素的褐腐真菌与外生菌根真菌物种。对31个真菌基因组（其中12个为本研究首次测序获得）的比较基因组分析显示，木质素降解过氧化物酶基因家族在通向伞菌纲祖先的演化支中发生了扩张，而该伞菌纲祖先被重建为白腐真菌物种；随后在通向褐腐真菌与外生菌根真菌的平行演化支中，该基因家族发生了收缩。分子钟(molecular clock)分析表明，木质素降解能力的起源可能与石炭纪(Carboniferous period)末期前后有机碳埋藏速率的骤降相吻合。