Auricularia heimuer is a wood-rotting edible mushroom, and with the continuous development of the industry, the research on its grass-rotting cultivation is becoming more and more important. In this study, A. heimuer was cultivated using herbaceous substrate (reed) completely replacing the traditional woody substrate (oak), and the correlation between the relative expression of cellulase gene, cellulase activity, cellulose degradation and yield of different strains of A. heimuer were studied by combining qRT-PCR technology at different growth stages. The results showed that the cellulose degradation were positively correlated with the yield of reed and sawdust substrate at two growth stages, and were positively correlated with three cellulase activities. The relative expression of four cellulase genes were positively correlated with enzyme activity. There were inter-strain differences in the expression of the enzyme genes, which were basically consistent with the trend of the enzyme activity of the strains; g5372 and g7270 were more actively expressed in the mycelium period, while g9664 and g10234 were more actively expressed in the fruiting period. The results of SEM showed that the mycelium of A15 and A125 were different in their ability to degrade and utilize lignocellulose in reed substrate. The parental hybridization test further verified that qRT-PCR could be used as a rapid method to evaluate the cellulose degradation ability of A. heimuer strains. Seven strains (A12, A15, A184, A224, Z6, Z12, and Z18) with high cellulose degradation ability were screened. This study provides a reference for further understanding the role of A. heimuer cellulase genes in the degradation and metabolism of cellulose and for breeding new varieties more suitable for herbaceous substrate cultivation.

Stropharia rugosoannulata is a mushroom that is rich in nutrients and has a pleasant flavor. Its cultivation area is expanding rapidly due to its simplicity and diversity. However, the developmental mechanism of the fruiting body, which constitutes the edible portion of S. rugosoannulata, remains to be elucidated. To address this knowledge gap, we conducted a comprehensive study. Our approach entailed the observation of sections through the fruiting body of S. rugosoannulata and the sequencing of the transcriptomes of various fruiting body tissues. The results demonstrated significant variations in the structure of the pileipellis, pileus, gill, veil, stipe, and trama of S. rugosoannulata. The predominant metabolic pathways included the amino acid metabolism of the pileus, sugar metabolism of the stipe, tryptophan metabolism, and wax production of the pileipellis, the DNA pathway of the gill, amino sugar metabolism of the veil, and the nitrogen metabolism of the trama. The promoter cis-element analysis revealed the roles of light response, methyl jasmonate, oxygen, and temperature on the differentiation of the veil, trama, and pileipellis, respectively. In summary, the present findings offer a molecular mechanism for the development of the fruiting body and provide directions for the enhancement of cultivation techniques of S. rugosoannulata.

Auricularia heimuer is a widely cultivated jelly mushroom. The fruiting bodies are categorized into cluster and chrysanthemum types. With changing consumer demands and the need to reduce bio-waste, the demand for clustered fruiting bodies is increasing. Therefore, gene mining for fruiting body types is a matter of urgency. We determined that the A. heimuer locus for fruiting body type was located at one end of the genetic linkage map. The locus was localized between the markers D23860 and D389 by increasing the density of the genetic linkage map. BlastN alignment showed that the marker SCL-18 was also located between D23860 and D389, and a total of 25 coding genes were annotated within this interval. Through parental transcriptome analysis and qRT-PCR verification, the locus g7219 was identified as the gene controlling the fruiting body type. A single-nucleotide substitution in the TATA box of g7219 was detected between the parents. By PCR amplification of the promoter region of g7219, the TATA-box sequences of the cluster- and chrysanthemum-type strains were found to be CATAAAA and TATAAAA, respectively. This study provides a foundation for the breeding of fruiting body types and strain improvement of A. heimuer.

The return of mushroom residue to the field is an effective measure to improve soil fertility and maintain agroecosystem productivity. We investigated the effects of returning Auricularia auricula residue to the field on the soil nutrients, enzyme activities, and microbial communities in rice–A. auricula rotation farmland. The return of 67.5 ton/ha A. auricula residue to the field significantly increased the contents of ammonium nitrogen, total nitrogen, total potassium, total phosphorus, available potassium (QK), available phosphorus, and organic matter by 180.49%, 70.41%, 16.3%, 54.35%, 137.33%, 38.84%, and 59.29%, respectively. The activities of urease, sucrase, β-glucosidase (β-GC), and acetyl-β-d-glucosidase significantly increased by 32.98%, 407.78%, 206.85%, and 186.26%, respectively; catalase and leucine aminopeptidase activities increased by 244.42% and 130.90% with the return of 54 ton/ha residue. Mushroom residue return increased the Chao1 and Shannon indices of the bacterial community but decreased the diversity of the fungal community. Redundancy analysis showed that QK, β-GC, and urease were closely associated with shifts in microbial community structure. Therefore, returning 67.5 ton/ha (149,925 bags) A. auricula residue to the field can enhance soil ecological functions by improving soil nutrients, enzyme activities, and microbial community structure.

To address the “fungus-forest conflict” in the edible mushroom industry and the challenge of resource utilization for bamboo substrate waste, this study focused on white Auricularia cornea, and cultivation systems were established with bamboo substrate replacing wood chips at ratios of 0%, 18%, 38%, 58%, and 78%. By integrating liquid chromatography–tandem mass spectrometry (LC-MS/MS) analysis with agronomic trait measurements, the study elucidated the metabolic adaptation mechanisms of the substrate. Results indicated that white A. cornea could grow normally in all bamboo substrates, with the 58% bamboo substrate replacement group (D_58) demonstrating the most optimal overall performance. The mycelial growth rate reached 3.55 ± 0.24 mm/d, and the growth period was the shortest (86.2 d), balancing growth efficiency with cost advantages. Metabolomics detected 3779 metabolites, primarily amino acids and their derivatives (42.2%) and organic acids (35.54%). Compared to the control group, each treatment group exhibited 104–528 upregulated and 192–630 downregulated differential metabolites, with 93 shared differential metabolites and numerous unique markers. KEGG pathway enrichment analysis revealed that varying bamboo substrate ratios shaped growth adaptation strategies by regulating core pathways such as nucleotide metabolism and ABC transporters. This study established the feasibility and optimal formulation of bamboo substrate substitution, elucidated the substrate–metabolite–phenotype linkage mechanism, and provided theoretical foundations and practical references for high-quality cultivation of white A. cornea and sustainable development through “substituting bamboo for wood” to reduce carbon emissions.

Auricularia heimuer is among China’s most important edible mushrooms and is rich in gum. With the improvement of people’s quality of life, demand is increasing for high-quality and good-tasting food; thus, the texture of A. heimuer is the focus of increasing attention. In this study, we added extra markers to a previously constructed genetic linkage map to generate a high-density genetic linkage map of A. heimuer, resolved the attributes of substrate quality-related traits, and performed quantitative trait locus (QTL) localization. The original genetic linkage map was improved by adding two new linkage groups, merging seven linkage groups into three linkage groups, and increasing the average linkage distance and total linkage estimated length. We anchored the 142 scaffolds of the genome to the improved genetic linkage map. In total, 15 significant QTLs controlling four quality-related traits were detected. Gumminess and chewiness, and cohesiveness and resilience, were linked. Three genes controlled cohesiveness and resilience; one gene controlled gumminess and chewiness. In conclusion, this study lays the foundation for gene localization and chromosome assembly in A. heimuer, elucidation of the mechanism of substrate quality-related trait formation, and provides a basis for precision breeding of A. heimuer.