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, degrading cellulose, hemicellulose and lignin in plant biomass to oligomers and monomers. 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 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. Overall design: This study compares the gene expression of A. bisporus A15 at different stages of its life cycle using the controlled environment of indoor commercial cultivation. The samples were taken at the spawning stage, primordial stage, first flush, after first flush, second flush and after second flush, respectively

双孢蘑菇（Agaricus bisporus）是一种担子菌（basidiomycete），自然栖息于北美与欧洲的森林及草原，以腐朽植物基质为营养源繁衍生长。该菌适配森林枯落物生境，参与全球碳循环，可将植物生物质中的纤维素、半纤维素与木质素降解为寡聚体与单体。同时，双孢蘑菇也是一种广泛栽培、具有重要经济价值的食用真菌。然而目前学界对该菌在可控栽培环境中的生长模式及基质利用机制仍知之甚少。本研究通过转录组学（transcriptomics）与蛋白质组学（proteomics）分析，发现双孢蘑菇对植物生物质的降解能力随其整个生命周期进程发生动态变化：木质素降解相关基因在接种发菌第16天呈高表达，其余生长阶段均维持低表达，这提示发菌阶段后木质素未被进一步修饰。本研究结果还揭示，首轮出菇期与二轮出菇期的纤维素、半纤维素降解相关基因表达存在显著差异，该差异可部分解释二轮出菇阶段子实体产量下降的现象。研究设计：本研究依托商业化室内可控栽培环境，对双孢蘑菇A15菌株生命周期各阶段的基因表达水平进行比较分析。样本依次采集于接种发菌阶段、原基形成阶段、首轮出菇期、首轮出菇后、二轮出菇期及二轮出菇后。