Comparative transcriptome analysis on candidate genes associated with fruiting body growth and development in Lyophyllum decastes.

Lyophyllum decastes is a mushroom that is highly regarded for its culinary and medicinal properties. Its delectable taste and texture make it a popular choice for consumption. To gain a deeper understanding of the molecular mechanisms involved in the development of the fruiting body of L. decastes, we used RNA sequencing to conduct a comparative transcriptome analysis. The analysis encompassed various developmental stages, including the vegetative mycelium, primordial initiation, young fruiting body, medium-size fruiting body, and mature fruiting body stages. A range of 40.1 to 60.6 million clean reads were obtained, and de novo assembly generated 15,451 unigenes with an average length of 1,462.68 bp. Functional annotation of transcriptomes matched 76.84% of the unigenes to known proteins available in at least one database. The gene expression analysis revealed a significant number of differentially expressed genes (DEGs) between each stage. These genes were annotated and subjected to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Highly differentially expressed unigenes were also identified, including those that encode extracellular enzymes, transcription factors, and signaling pathways. The accuracy of the RNA-Seq and DEG analyses was validated using quantitative PCR. Enzyme activity analysis experiments demonstrated that the extracellular enzymes exhibited significant differences across different developmental stages. This study provides valuable insights into the molecular mechanisms that underlie the development of the fruiting body in L. decastes.

Polysaccharides from Lyophyllum decastes reduce obesity by altering gut microbiota and increasing energy expenditure.

Polysaccharides are known to confer protection against obesity via modulation of gut microbiota. To expand our knowledge of mushroom-derived prebiotics, we investigated the structural characteristics and anti-obesity effects of Lyophyllum decastes polysaccharides. Two heteroglycans were purified and characterized. The isolated polysaccharides effectively reduced obesity and the related disorders in the diet-induced obese (DIO) mice. An altered gut microbiota with enrichments of Bacteroides intestinalis and Lactobacillus johnsonii and an increase of secondary bile acids were detected in the polysaccharide-treated mice. Supplementation of B. intestinalis and L. johnsonii prevented the obesity and hyperlipidemia in DIO mice, demonstrating their causal linkage to the efficacy of polysaccharides. An enhancement of energy expenditure in the brown adipose tissues due to up-regulation of the secondary bile acids-activated TGR5 pathway was deduced to be one of the mechanisms underlying the effect of polysaccharides. These results confirmed Lyophyllum decastes-derived polysaccharides as new prebiotics for preventing and treating obesity.

A revision of Agaricus section Arvenses with nine new species from China.

Agaricus sect. Arvenses includes numerous species that are potential candidates for cultivation, and some have high nutritional and medicinal interests. Between 2012 and 2017, 147 specimens of A. sect. Arvenses were collected in China. For this study, nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS), nuc 28S rDNA (28S), and translation elongation factor 1-alpha (tef1) sequences were used to assess species boundaries of these samples from China. Combined with morphological examination, we recognize 22 species of A. sect. Arvenses from China, of which 12 are known species, one is new record for China, and nine are proposed as new.

Ascomycetes from the Qilian Mountains, China - Hypocreales.

To investigate fungi from the Qilian Mountains in Gansu Province, ascomycetous specimens were collected and hypocrealean fungi were examined. Eighteen species belonging to six genera in the families Hypocreaceae and Nectriaceae were identified, including 11 species of Hypomyces and Trichoderma in Hypocreaceae and seven species of Nectria, Stylonectria, Thelonectria, and Thyronectria in Nectriaceae. Among them, Stylonectria qilianshanensis and Trichoderma gansuanum are new to science. DNA sequence analyses of combined ACL1, ITS, RPB2, and TEF1 regions confirmed their taxonomic placements. Morphological distinctions between the new species and their close relatives are discussed. Hypomyces tremellicola is reported for the first time in China.

A putative transcription factor LFC1 negatively regulates development and yield of winter mushroom.

Basidioma is the fruiting body of mushroom species. The deep understanding on the mechanism of basidioma development is valuable for mushroom breeding and cultivation. From winter mushroom (Flammulina velutipes), one of the top five industrially cultivated mushrooms, a novel putative Zn(II)2Cys6 transcription factor LFC1 with negative regulatory function in basidioma development was identified. The transcript level of lfc1 was dramatically decreased during basidioma development. Neither overexpression nor knockdown of lfc1 affected hyphal vegetative growth. However, knockdown of lfc1 could promote basidioma development and shorten cultivation time by 2 days, while overexpression of lfc1 delayed the optimal harvest time by 3 days. In the lfc1 knockdown strain, in which the lfc1 expression was reduced by 72%, mushroom yield and biological efficiency could be increased at least by 24%. Knockdown of lfc1 did not affect the shape of caps but significantly increased basidioma length and number, while its overexpression did not affect basidioma length but dramatically reduced basidioma number. In addition, rather than producing basidiomata with round caps as in wild type, the caps of basidiomata in the lfc1 overexpression mutants were significantly larger and the cap edge was wrinkled. RNA-seq analysis revealed that 455 genes had opposite transcriptional responses to lfc1 overexpression and knockdown. Some of them were previously reported as genes involved in basidioma development, including 3 hydrophobin encoding genes, 2 lectin encoding genes, FVFD16, an Eln2 ortholog encoding gene, and 3 genes encoding membrane components. As LFC1 homologs are widely present in mushroom species, lfc1 can be useful in mushroom breeding.Key Points• A novel transcription factor LFC1 negatively regulates fruiting in winter mushroom• LFC1 regulated transcription of more than 400 genes.• Reduction of LFC1 expression could shorten cultivation time and increase yield.• lfc1 could be a potentially useful reference gene for mushroom breeding.

A WD40 Protein Encoding Gene Fvcpc2 Positively Regulates Mushroom Development and Yield in Flammulina velutipes.

Ascomycota and Basidiomycota are two closely related phyla and fungi in two phyla share some common morphological developmental process during fruiting body formation. In Neurospora crassa, the Gß-like protein CPC-2 with a seven-WD40 repeat domain was previously reported. By transforming CPC-2 ortholog encoding genes, from 7 different fungal species across Ascomycota and Basidiomycota, into the cpc-2 deletion mutant of N. crassa, we demonstrate that all tested CPC-2 ortholog genes were able to complement the defects of the cpc-2 deletion mutant in sexual development, indicating that CPC-2 proteins from Ascomycota and Basidiomycota have the similar cellular function. Using Flammulina velutipes as a model system for mushroom species, the CPC-2 ortholog FvCPC2 was characterized. Fvcpc2 increased transcription during fruiting body development. Knockdown of Fvcpc2 by RNAi completely impaired fruiting body formation. In three Fvcpc2 knockdown mutants, transcriptional levels of genes encoding adenylate cyclase and protein kinase A catalytic subunit were significantly lower and colony growth became slower than wild type. The addition of cAMP or the PKA-activator 8-Bromo-cAMP into the medium restored the Fvcpc2 knockdown mutants to the wild-type colony growth phenotype, suggesting that the involvement of cAMP production in the regulatory mechanisms of FvCPC2. Knockdown of Fvcpc2 also weakened transcriptional responses to sexual development induction by some genes related to fruiting body development, including 4 jacalin-related lectin encoding genes, 4 hydrophobin encoding genes, and 3 functionally-unknown genes, suggesting the participation of these genes in the mechanisms by which FvCPC2 regulates fruiting body development. All three Fvcpc2 overexpression strains displayed increased mushroom yield and shortened cultivation time compared to wild type, suggesting that Fvcpc2 can be a promising reference gene for Winter Mushroom breeding. Since the orthologs of FvCPC2 were highly conserved and specifically expressed during fruiting body development in different edible mushrooms, genes encoding FvCPC2 orthologs in other mushroom species also have potential application in breeding.