Winter Mushroom Flammulina Velutipes Research Articles

The transcription factor FvHmg1 negatively regulates fruiting body development in Winter Mushroom Flammulina velutipes.

Fruiting body formation in Agaricomycetes represents the most complex and unclear process in the fungi. Mating type pathways (matA and matB) and transcription factors are important regulators in the process. Here, we report a new High-mobility-group (HMG) box domain protein FvHmg1 that acts as a negative transcription regulator in fruiting body development in Winter Mushroom Flammulina velutipes. However, the expression of Fvhmg1 in dikaryon and primordial stages was significantly lower than that of monokaryon. The Fvhmg1-RNAi mutants had a better ability of fruiting than wild type strain. Overall expression of Fvhmg1 was controlled under compatible matA and matB genes where compatible matA genes could increase its expression level, while compatible matB genes had the opposite effect. It means when two monokaryons with compatible matA and matB genes were crossed, the negatively transcription factor FvHmg1 was inhibited, and normal fully fruiting body could formation and develop. The relationship between FvHmg1 and mating type pathway would advance to understand of sexual reproduction and fruiting body development in edible mushrooms.

Вплив складу рослинних субстратів на ефективність культивування їстівних грибів Cyclocybe aegerita (V. Brig.), Pleurotus eryngii (DC.) Quel., Pleurotus citrinopileatus Singer та Flammulina velutipes (Curtis) Singer

Influence of plant substrate composition on the efficiency of edible mushrooms cultivation Cyclocybe aegerita (V. Brig.), Pleurotus eryngii (DC.) Quel., Pleurotus citrinopileatus Singer and Flammulina velutipes (Curtis) Singer. The possibility of using plant substrates based on straw and sunflower husk, with the addition of rape seeds and corn processing waste for the cultivation of edible xylotrophic mushrooms: poplar mushroom, lemon-hat oyster mushroom and winter mushroom (white and yellow races) was investigated. The optimal formula of the substrate was established, the use of which increases the biological effectiveness of the studied strains and reduces the time required for obtaining fresh fruit bodies. Keywords: lemon-cap oyster mushroom Pleurotus citrinopileatus, poplar mushroom Cyclocybe aegerita, winter mushroom Flammulina velutipes, biological efficiency, technological cyclemushrooms (Flammulina velutipes), biological efficiency, technological cycle.

Phylogeny and species delimitation of Flammulina: taxonomic status of winter mushroom in East Asia and a new European species identified using an integrated approach

The winter mushroom, or Enokitake, is economically important and commercially cultivated on a large scale in East Asia. However, the phylogeny and species delimitation of the winter mushroom genus (Flammulina) have not been fully clarified. In this study, 81 collections of Flammulina from East Asia, Europe, and North America were studied, and their phylogeny and species delimitation were inferred from partial sequences of the ITS, tef1-α, rpb2, and homeodomain1 (HD1) of the mating gene (labeled as HD1-A). Genetic structure analyses based on genomic SSR markers and haplotype network analysis based on HD1-A were also used to delimit several closely related taxa. Twelve phylogenetic species were recognized, which was largely consistent with previous studies. However, our integrated studies indicated that Enokitake is not identical to the European winter mushroom Flammulina velutipes, and thus should be treated as a separate species, namely Flammulina filiformis. All cultivated strains of “F. velutipes” in East Asia, including those from South Korea and Japan with genome sequences labeled as such, are in fact F. filiformis. A new species, Flammulina finlandica, was also unexpectedly discovered in Northern Europe. Morphological descriptions of these two species, color photos of their fresh basidiomata, and line drawings of their microscopic features are presented.

Phenotypic and Genetic Diversity of the Culinary-Medicinal Winter Mushroom Flammulina velutipes (Agaricomycetes) in China.

Flammulina velutipes is one of the mushrooms produced most widely in East Asia. In this study we investigated phenotypic variations of 7 agronomic traits in 37 F. velutipes strains from China, and we analyzed their genetic diversity with 70 simple sequence repeat markers. The Shannon information index and gene diversity were 0.894 and 0.478, respectively, demonstrating high genetic variation among the tested strains. Poor genetic variation was found among white strains, in contrast to yellow ones. Analysis of population structure resolved 2 unambiguous genetic groups in the tested F. velutipes strains, with little differentiation between them (FST = 0.016). Yellow cultivars possibly originated from indigenous wild strains in southwest China. Phenotypic correlations were identified among the 7 traits. In particular, stipe length (SL) was significantly positively correlated with yield, indicating that SL could be used as an index for breeding high-yield strains. The 2 genetic groups, and white strains and yellow ones, showed significant differences between SL, yield, and the time interval (days) from mycelial scratch to formation of the first fruiting body. These results indicate that these 3 traits were stratified by population structure. Detection of genetic and phenotypic variations would lay the groundwork for further breeding of elite F. velutipes strains.

Depigmenting Effect of Winter Medicinal Mushroom Flammulna velutipes (Higher Basidiomycetes) on Melanoma Cells.

In humans, skin pigmentation results from the biochemichal synthesis and accumulation of melanin. We previously revealed that edible winter mushroom Flammulina velutipes extract inhibited melanosis in commercially available edible crustacea. Therefore, the current study was conducted to find if edible mushrooms extracts are useful for the skin whitening and the underlying mechanisms in melanin biosynthesis. Tyrosinase is one of the key enzymes for melanin biosynthesis. This study demonstrated that melanin synthesis and tyrosinase activity were suppressed by the F. velutipes extracts in B16 murine melanoma cells through the slow expression of microphthalmia-associated transcription factor. These results suggested that the F. velutipes extract could contain an effective component in whitening cosmetics and an alternative therapeutic agent for treating hyperpigmentation.

Endo-β-1,3-galactanase from Winter Mushroom Flammulina velutipes

Arabinogalactan proteins are proteoglycans found on the cell surface and in the cell walls of higher plants. The carbohydrate moieties of most arabinogalactan proteins are composed of β-1,3-galactan main chains and β-1,6-galactan side chains, to which other auxiliary sugars are attached. For the present study, an endo-β-1,3-galactanase, designated FvEn3GAL, was first purified and cloned from winter mushroom Flammulina velutipes. The enzyme specifically hydrolyzed β-1,3-galactan, but did not act on β-1,3-glucan, β-1,3:1,4-glucan, xyloglucan, and agarose. It released various β-1,3-galactooligosaccharides together with Gal from β-1,3-galactohexaose in the early phase of the reaction, demonstrating that it acts on β-1,3-galactan in an endo-fashion. Phylogenetic analysis revealed that FvEn3GAL is member of a novel subgroup distinct from known glycoside hydrolases such as endo-β-1,3-glucanase and endo-β-1,3:1,4-glucanase in glycoside hydrolase family 16. Point mutations replacing the putative catalytic Glu residues conserved for enzymes in this family with Asp abolished activity. These results indicate that FvEn3GAL is a highly specific glycoside hydrolase 16 endo-β-1,3-galactanase.

Electrophoretic karyotyping and construction of a bacterial artificial chromosome library of the winter mushroom Flammulina velutipes

An electrophoretic karyotype of Korean Flammulina velutipes was obtained using contour-clamped homogeneous electric field (CHEF) gel electrophoresis. The monokaryotic progenies (4019-20 and 4019-18) and a dikaryotic strain (4019-2018) had 6-8 chromosomes, with sizes ranging from 1.6 to 5.8 megabase (Mb) pairs. Among the 3 strains that were examined, strain 4019-20 resolved into at least 7 chromosomes, with a total genome size of approximately 26.7Mb. We selected several chromosome-specific genes from the cDNA library of F. velutipes using Southern hybridization analysis. In order to determine the whole genome sequence, we constructed a bacterial artificial chromosome (BAC) library of the 4019-20 strain. The BAC library comprised 3840 clones, and the insert size ranged from 60 to 228kb, with an average size of 136kb.

Gravitropic bending of fruiting bodies-a model based on hyphal gravisensing and cooperativity

Gravitropic bending of the winter mushroom Flammulina velutipes is achieved by differential growth of the apical part of the stem, the transition zone. Ultrastructural analysis revealed that bending is due to the relaxation of tissue tensions at the lower flank of the stem where hyphal extension growth is promoted in contrast to the upper flank. Extension of lower flank hyphae is preceded by a conspicuous accumulation of microvesicles in the cytosol and their subsequent fusion with the vacuolar compartment, leading to a large volume increase. The hypothesis is put forward that all hyphae in the transition zone are capable of gravisensing. It is derived from experiments with transition zone segments, which exhibit negative gravitropic response independent from their origin within the stem. A model is presented which connects individual gravisensing of the hyphae with a cooperative response within the stem or small segments of the stem. An essential step is the transmission of positional information, by each hypha with respect to the gravitational vector, to the surroundings. The existence of a soluble growth regulator, which is enriched at the lower flank of the stem, is discussed. A gradient could be formed which precedes the gradient of microvesicle formation, and thereby determines the change of growth direction.