Characterization of a mycovirus associated with the brown discoloration of edible mushroom, Flammulina velutipes.

Background: A mycovirus previously identified in brown discolored fruiting bodies of the cultivated mushroom Flammulina velutipes was characterized. We tentatively named the virus the F. velutipes browning virus (FvBV).

Differentially expressed genes under simulated microgravity in fruiting bodies of the fungus Pleurotus ostreatus.

In response to a change in the direction of gravity, morphogenetic changes of fruiting bodies of fungi are usually observed as gravitropism. Although gravitropism in higher fungi has been studied for over 100 years, there is no convincing evidence regarding the graviperception mechanism in mushrooms. To understand gravitropism in mushrooms, we isolated differentially expressed genes in Pleurotus ostreatus (oyster mushroom) fruiting bodies developed under three-dimensional clinostat-simulated microgravity.

The fruiting-specific Le.flp1 gene, encoding a novel fungal fasciclin-like protein, of the basidiomycetous mushroom Lentinula edodes.

To understand the molecular mechanisms of fruiting body formation of basidiomycetous mushrooms, we have isolated over a 100 of developmentally regulated genes that were specifically transcribed during fruiting body development in Lentinula edodes (Shiitake-mushroom) by a subtractive hybridization, cDNA-RDA (cDNA representational difference analysis). One of these genes, named Le.flp1, was isolated from the primordial cDNA library of L.

Transformation of the mycorrhizal basidiomycetes, Suillus grevillei and S. bovinus, by particle bombardment.

Mycorrhizal basidiomycetes, Suillus grevillei and S. bovinus, were transformed by particle bombardment. We isolated eight and four transformants from S.

Expression of the autofluorescent protein, DsRed2, in the recombinants of the ectomycorrhizal basidiomycete, Suillus grevillei, generated by Agrobacterium-mediated transformation.

Recombinants were generated from the ectomycorrhizal basidiomycete, Suillus grevillei, through agroinfection using a binary vector carrying the hygromycin B resistance and the autofluorescent protein, DsRed2, markers. DsRed2 was driven by a cis-regulatory region of the glyceraldeyde-3-phosphate dehydrogenase gene (gpd) from the wood-rotting basidiomycete, Coriolus hirsutus, which contains promoters and 5' gpd sequences with first through fourth exons and expressed for the first time in Suillus spp. The transformation system and recombinants expressing an autofluorescent protein may be useful in genetic analysis of the symbiosis.

Isolation of genes differentially expressed during the fruit body development of Pleurotus ostreatus by differential display of RAPD.

To analyze genes involved in fruit body development of Pleurotus ostreatus, mRNAs from three different developmental stages: i.e., vegetative mycelium, primordium, and mature fruit body, were isolated and reverse-transcribed to cDNAs.

Transformation of the edible mushroom Pleurotus ostreatus by particle bombardment.

Uracil auxotroph of Pleurotus ostreatus was transformed to prototrophy by means of particle bombardment. Five transformants were obtained under three conditions differing in the two parameters of target distance and helium pressure. The transformation frequency was one transformant per microg of DNA.