Table_1_Build Your Own Mushroom Soil: Microbiota Succession and Nutritional Accumulation in Semi-Synthetic Substratum Drive the Fructification of a Soil-Saprotrophic Morel.XLSX

Black morel, a widely prized culinary delicacy, was once an uncultivable soil-saprotrophic ascomycete mushroom that can now be cultivated routinely in farmland soils. It acquires carbon nutrients from an aboveground nutritional supplementation, while it remains unknown how the morel mycelium together with associated microbiota in the substratum metabolizes and accumulates specific nutrients to support the fructification. In this study, a semi-synthetic substratum of quartz particles mixed with compost was used as a replacement and mimic of the soil. Two types of composts (C1 and C2) were used, respectively, plus a bare-quartz substratum (NC) as a blank reference. Microbiota succession, substrate transformation as well as the activity level of key enzymes were compared between the three types of substrata that produced quite divergent yields of morel fruiting bodies. The C1 substratum, with the highest yield, possessed higher abundances of Actinobacteria and Chloroflexi. In comparison with C2 and NC, the microbiota in C1 could limit over-expansion of microorganisms harboring N-fixing genes, such as Cyanobacteria, during the fructification period. Driven by the microbiota, the C1 substratum had advantages in accumulating lipids to supply morel fructification and maintaining appropriate forms of nitrogenous substances. Our findings contribute to an increasingly detailed portrait of microbial ecological mechanisms triggering morel fructification.

黑羊肚菌是广受赞誉的烹饪珍品，曾是无法人工培育的土生腐生子囊菌，如今已可在农田土壤中实现规模化常规栽培。该真菌通过地上营养补给获取碳源养分，但目前学界仍未明确羊肚菌菌丝体与基质内附属微生物群落如何协同代谢并积累特定营养物质以支撑其子实体发生。本研究采用石英颗粒与堆肥混合的半合成基质作为土壤的替代模拟物，分别使用两种堆肥（C1、C2），并以纯石英基质（NC）作为空白对照。针对三种羊肚菌子实体产量差异显著的基质，本研究对比分析了其中的微生物群落演替、基质转化过程以及关键酶活性水平。产量最高的C1基质中，放线菌门（Actinobacteria）与绿弯菌门（Chloroflexi）的相对丰度更高；相较于C2与NC基质，C1基质内的微生物群落在子实体发生阶段可抑制携带固氮基因的微生物（如蓝细菌门Cyanobacteria）的过度增殖。在微生物群落的驱动下，C1基质在积累脂质以支撑羊肚菌子实体发生，以及维持适宜形态的含氮物质方面具备优势。本研究结果进一步完善了调控羊肚菌子实体发生的微生物生态机制的认知图景。