Auricularia heimuer is one of the most popular edible fungi in China. In this study, the whole genome of A. heimuer was sequenced on the Illumina HiSeq X system and compared with other mushrooms genomes. As a wood-rotting fungus, a total of 509 carbohydrate-active enzymes (CAZymes) were annotated in order to explore its potential capabilities on wood degradation. The glycoside hydrolases (GH) family genes in the A. heimuer genome were more abundant than the genes in the other 11 mushrooms genomes. The A. heimuer genome contained 102 genes encoding class III, IV, and V ethanol dehydrogenases. Evolutionary analysis based on 562 orthologous single-copy genes from 15 mushrooms showed that Auricularia formed an early independent branch of Agaricomycetes. The mating-type locus of A. heimuer was located on linkage group 8 by genetic linkage analysis. By combining the genome sequence analysis with the genetic linkage map, the mating-type locus of A. heimuer was located on scaffold45 and consisted of two subunits, α and β. Each subunit consisted of a pair of homeodomain mating-type protein genes HD1 and HD2. The mapping revealed conserved synteny at the whole mating-type loci and mirror symmetry relations near the β subunit between A. heimuer and Exidia glandulosa. This study proposed the potential for the bioethanol production by consolidated bioprocessing of A. heimuer. It will promote understanding of the lignocellulose degradation system and facilitate more efficient conversion of the agricultural wastes used for mushroom cultivation. It also will advance the research on the fruiting body development and evolution of A. heimuer.

Color is a crucial feature to consider when breeding and improving strains of Auricularia cornea. To uncover the mechanism of white strain formation in A. cornea, this study selected parental strains that were homozygous for the color trait and analyzed the genetic laws of A. cornea color through genetic population construction, such as test-cross, back-cross, and self-cross populations, and the statistical analysis of color trait segregation. Moreover, the study developed SSR molecular markers to construct a genetic linkage map, perform the fine mapping the color-controlling genetic locus, and verify candidate genes using yeast two-hybrid, transcriptome analysis, and different light treatments. The results of the study indicated that the color trait of A. cornea is controlled by two pairs of alleles. When both pairs of loci are dominant, the fruiting body is purple, while when both pairs of loci are recessive or one pair of loci is recessive, the fruiting body is white. Based on the linkage map, the study finely mapped the color locus within Contig9_29,619bp-53,463bp in the A. cornea genome and successfully predicted the color-controlling locus gene A18078 (AcveA), which belongs to the Velvet factor family protein and has a conserved structure domain of the VeA protein. It can form a dimer with the VelB protein to inhibit pigment synthesis in filamentous fungi. Lastly, the study validated the interaction between AcVeA and VelB (AcVelB) in A. cornea at the gene, protein, and phenotype levels, revealing the mechanism of inhibition of pigment synthesis in A. cornea. Under dark conditions, dimerization occurs, allowing it to enter the nucleus and inhibit pigment synthesis, leading to a lighter fruiting body color. However, under light conditions, the dimer content is low and cannot enter the nucleus to inhibit pigment synthesis. In summary, this study clarified the mechanism of white strain formation in A. cornea, which could aid in improving white strains of A. cornea and studying the genetic basis of color in other fungi.

Larch wood, a prevalent cultivation medium for Ganoderma tsugae, has yet to be scrutinized concerning the differential impacts of sterilized and non-sterilized substrates on the growth and development of this fungus. Our present investigation sought to elucidate these effects in a forest-like environment. After larch wood segments were sun-dried, they were divided into two groups; one group was bagged and autoclaved, while the other group was bagged without any treatment. Subsequently, all segments were inoculated with the G. tsugae strain HLXL1 and ensconced under the canopy of a Pinus koraiensis forest, thereby approximating the conditions of natural growth. Wild G. tsugae was used as the control. Data on agronomic traits, production days, fruiting body yield, and effective constituent content were analyzed. The results indicated no significant differences between sterilized and non-sterilized substrates in terms of agronomic traits. However, the mineral content and bioactive compounds in G. tsugae fruiting bodies significantly differed across various growth stages. The outcomes were optimal for non-sterilized substrates, followed by sterilized substrates, while the wild strains were markedly less effective than the cultivated ones.

Sarcomyxa edulis is a characteristic edible and medicinal mushroom found in Northeast China that is highly valued by consumers for its tender texture, pleasant flavor, and high nutritional value. To gain a deeper understanding of the molecular mechanisms underlying the development of S. edulis fruiting bodies, this study utilized the Illumina NovaSeq platform to perform transcriptome sequencing at three growth and development stages of S. edulis strain SE8, namely primordia (SE8–P), fruiting body differentiation (SE8–F), and mature fruiting body (SE8–M). A total of 54.67 Gb of clean data was obtained, with a GC content of around 51%. After assembly, 36,423 Unigenes were obtained. Functional annotation was performed on the Unigenes, resulting in 21,206 Unigene annotation results. Differential expression gene analysis showed that 79,606 and 523 DEGs were annotated in at least one database during the SE8–P vs. SE8–F, SE8–F vs. SE8–M, and SE8–P vs. SE8–M processes, respectively. Among these, the genes encoding aldehyde dehydrogenase and fungal hydrophobins were consistently downregulated, playing a negative regulatory role in the growth and development of S. edulis. The genes encoding glycoside hydrolase and AB hydrolase superfamily proteins were consistently upregulated, playing a positive regulatory role in growth and development. Among these, the genes encoding aldehyde dehydrogenase were annotated to the Tryptophan metabolism (ko00380) pathway through KEGG, suggesting that aldehyde dehydrogenase regulates indoacetate formation in the fruiting body of S. edulis. The accuracy of RNA–Seq and DEG analysis was validated using quantitative PCR. This study enriches our knowledge of the genetic information and provides a theoretical basis for the molecular mechanisms of fruiting body development of S. edulis.