Uncovering the abilities of Agaricus bisporus to degrade plant biomass throughout its life cycle

The common edible mushroom Agaricus bisporus is a basidiomycete that thrives on decaying plant material in the forests and grasslands of North America and Europe. It is adapted to forest litter and contributes to global carbon recycling, depolymerizing cellulose, hemicellulose and lignin in plant biomass. A. bisporus is also an edible mushroom that is widely cultivated and economically important. However, relatively little is known about how A. bisporus grows in this controlled environment in commercial production facilities and utilizes its substrate. Using transcriptomics and proteomics, we showed that changes in plant biomass degradation by A. bisporus occur throughout its life cycle. Ligninolytic genes were highly expressed during the spawning stage day 16 and had low expression during all the other growth stages which could indicate that lignin is not modified after the spawning stage. Our results also revealed differences in gene expression involved in cellulose and hemicellulose degradation between the first and second flushes. This could partially explain the reduction in the number of mushrooms during the second flush.

常见食用真菌双孢蘑菇（Agaricus bisporus）属于担子菌，在北美与欧洲的森林及草原生境中以腐朽植物基质为营养来源并旺盛生长。该菌适配森林枯落物环境，参与全球碳循环过程，可降解植物生物质中的纤维素、半纤维素与木质素。双孢蘑菇同时也是一种被广泛栽培、具有重要经济价值的食用真菌。然而，目前学界对双孢蘑菇在商业生产设施的可控环境中如何生长、并利用栽培基质的机制仍知之甚少。本研究借助转录组学（transcriptomics）与蛋白质组学（proteomics）技术，发现双孢蘑菇对植物生物质的降解能力变化贯穿其整个生命周期。木质素降解相关基因在接种发菌阶段第16天呈高表达，而在其余所有生长阶段的表达量均较低，这提示木质素在接种发菌阶段之后未发生显著修饰。本研究结果还显示，纤维素与半纤维素降解相关基因的表达量在第一潮菇与第二潮菇之间存在显著差异，该差异可部分解释第二潮菇的产量下降现象。