Mycoscience最新文献

Identifying the mating-type in Mycoleptodonoides aitchisonii is important for enhancing breeding and cultivation of this edible mushroom. To clarify the molecular mechanisms of the bipolar mating system in M. aitchisonii, the homeodomain protein gene 2 (Mahd2) was characterized. A genomic DNA fragment of Mahd2 in M. aitchisonii 50005-18 strain was 1,851 bp long and encoded a protein of 614 amino acids. Transcriptional analysis revealed that the expression of Mahd2 was higher in monokaryotic strains that produced clamp cells than in those that did not. The highest relative expression level of Mahd2 was observed in monokaryon TUFC 50005-4, which was capable of forming a true clamp. These results suggested that the formation of clamp cells is regulated by A-mating type homeodomain proteins, and the frequency of clamp cell formation might be promoted by high expression of the Mahd2 gene.

The cultivation of edible mycorrhizal fungi (EMF) has made great progress since the first cultivation of Tuber melanosporum in 1977 but remains in its infancy. Five cultivation steps are required: (1) mycorrhizal synthesis, (2) mycorrhiza development and acclimation, (3) out-planting of mycorrhizal seedlings, (4) onset of fructification, and (5) performing tree orchards. We provide examples of successes and challenges associated with each step, including fruiting of the prestigious chanterelles in Japan recently. We highlight the challenges in establishing performing tree orchards. We report on the monitoring of two orchards established between Lactarius deliciosus (saffron milk cap) and pines in New Zealand. Saffron milk caps yields reached 0.4 and 1100 kg/ha under Pinus radiata and P. sylvestris 6 and 9 y after planting, respectively. Canopy closure began under P. radiata 7 y after planting, followed by a drastic reduction of yields, while P. sylvestris yields still hovered at 690 to 780 kg/ha after 11 y, without canopy closure. The establishment of full-scale field trials to predict yields is crucial to making the cultivation of EMF a reality in tomorrow's cropping landscape. Sustainable EMF cultivation utilizing trees in non-forested land could contribute to carbon storage, while providing revenue and other ecosystem services.

The obligate biotrophic oomycete genus Pustula is one of the four major linages of white blister rusts (Albuginaceae) identified so far. Species of the genus Pustula cause white blister rust on numerous genera in the asterids, represented by several phylogenetically distinct genus-specific lineages, most of which still await formal description. Thus, the observation of the species of Pustula on the Asteraceae subfamily Gymnorhenoideae pointed out to the existence of a hitherto undescribed species. By the morphological and molecular phylogenetic investigation conducted in this study it is concluded that the pathogen on Gymnarrhena micrantha from Iran indeed represents a hitherto unknown species and is described as P. persica. This species has apparently adapted to desert condition and is, after Albugo arenosa, the second species of white blister rust from Iranian deserts, highlighting the adaptability of white blister rusts to hot and dry habitats.

Racodium therryanum is a snow mold causing snow blight and seed rot in conifers. The sexual stage of R. therryanum has not been found, however, it has been speculated that Herpotrichia juniperi, which causes brown felt blight, is the sexual stage of R. therryanum. In this study, we conducted phylogenetic analysis using 28S large subunit (LSU) rDNA, 18S small subunit (SSU) rDNA, translation elongation factor 1-alpha (tef1), and RNA polymerase II second largest subunit (rpb2). Four isolates were identified as R. therryanum based on their morphological characteristics; together with two strains of H. juniperi, they composed a clade supported by high bootstrap and Bayesian posterior probability values. Therefore, we conclude that the snow mold previously described as R. therryanum is phylogenetically H. juniperi.

Hemileia gardeniae-floridae is an accepted name for a Cape jasmine (Gardenia jasminoides) rust fungus distributed in East Asia. The fungus name was based on uredinial anamorph collected in Taiwan in 1931. The fungus was rarely collected in Taiwan and southern Japan, and its telial stage remained unknown. Microscopic examination of the type materials of H. gardeniae-floridae and Uredo gardeniae-floridae, which was once proposed to replace H. gardeniae-floridae, resulted in discovery of teliospores on the type of U. gardeniae-floridae. The teliospores are mostly napiform and produced on a sporogenous cell emerging through host stoma. A hemileioid rust fungus, producing both urediniospores and teliospores on Golden gardenia (G. sootepensis), was found in Thailand and morphologically identified to H. gardeniae-floridae. Another Hemileia species on Forest jasmine (G. thunbergia), H. gardeniae-thunbergiae, first found in Angola, Africa, is distinct from H. gardeniae-floridae in producing smaller urediniospores than those of H. gardeniae-floridae.

Bassiatin which is produced by some fungi, is morpholine-based depsipeptide. Recent studies show that bassiatin inhibits MCF-7 breast cancer cell proliferation with its anti-oestrogenic effect. In this study, bassiatin's inhibition versus Tamoxifen was examined by comparing the effects on epidermal growth factor receptor and vascular endothelial growth factor receptor in addition to oestrogen receptor on breast cells. For this purpose, 15 concentrations of bassiatin, tamoxifen and combination of both were treated in terms of cytotoxicity on MCF-7, MDA-MB-231, SK-BR-3 and SVCT cell lines. For cell cycle analyses, MCF-7 and SVCT cell lines were incubated with 37.5 μM bassiatin, tamoxifen and combined substance for 24 h and 48 h. After treatment, cell distribution in each phase of the cell cycle was measured with flow cytometer. Furthermore, each interaction related to receptors were investigated with immunoassay ELISA kits. As a result, bassiatin-induced MCF-7 cell cycle arrest was shown in G0/G1 and G2/M phases at the presence of bassiatin. It was also found that bassiatin is more effective at all examined receptors on breast cancer cells than tamoxifen. These results show that bassiatin can be used effectively in breast cancer treatment as a new anticancer agent because of its multiple inhibition effects.

We hypothesised that cadmium exposure would hinder growth and secretion of carbon-degrading enzymes by mycorrhizal fungi, and that this would vary according to their tolerance to cadmium stress. The enzymes measured were β-Glucosidase, β-Xylosidase, β-D-cellubiosidase, N-acetyl-β-Glucosaminidase in three strains of ectomycorrhizal fungi Hebeloma subsaponaceum, Scleroderma sp., Hebeloma sp. and a feremycorrhizal fungus Austroboletus occidentalis. Fungi were subjected to cadmium stress for 28 d (in modified Melin-Norkrans liquid medium). The results showed unanticipated differential response of enzyme activities among the fungal species, including potential hormesis effects. Austroboletus occidentalis showed an increase in enzyme activity under cadmium stress.

Developing high-content strains of L-ergothioneine (EGT), an antioxidant amino acid, is an important breeding target for tamogitake mushroom, Pleurotus cornucopiae var. citrinopileatus. We constructed a genetic linkage map based on segregation analysis of markers in 105 F1 progenies. The loci of 245 markers, including 10 AFLP markers, 195 Rad markers, 2 mating type factors, and 38 gene markers, were mapped. The map contained 12 linkage groups with a total genetic distance of 906.8 cM, and an average marker interval of 4.0 cM. The population from crossing between tester monokaryon and F1 progenies was used to characterize quantitative trait loci (QTL) for EGT content. With composite interval mapping (CIM) method, QTL of EGT content were found to be located in linkage group 10, having a Logarithm of the odds (LOD) score of 2.53 with a 10.1% contribution rate. Moreover, a single nucleotide polymorphism (SNP), A/T, was identified in a gene region of the genome in the neighborhood where the QTL peak existed. This SNP genotype was in good agreement with the EGT phenotypes of each strain in the both QTL population and wild population. Thus, this SNP would have great potential value to use the marker-assisted selection (MAS) for this mushroom with high EGT content.

The resinicolous fungi Sarea difformis and S. resinae (Sareomycetes) were taxonomically revised on the basis of morphological observations and phylogenetic analyses of the nucleotide sequences of the nSSU-LSU-rpb1-rpb2-mtSSU genes. The results of phylogenetic analyses show that S. difformis and S. resinae are grouped with members of Xylonomycetes. According to the results of phylogenetic analyses and their sexual and asexual morphs resemblance, Sareomycetes is synonymized with Xylonomycetes. Although Tromera has been considered a synonym of Sarea based on the superficial resemblance of the sexual morph, we show that they are distinct genera and Tromera should be resurrected to accommodate T. resinae (= S. resinae). Xylonomycetes was morphologically re-circumscribed to comprise a single family (Xylonaceae) with four genera (Sarea, Trinosporium, Tromera, and Xylona) sharing an endophytic or plant saprobic stage in their lifecycle, ascostroma-type ascomata with paraphysoid, Lecanora-type bitunicate asci, and pycnidial asexual morphs. Phylogenetic analyses based on ITS sequences and environmental DNA (eDNA) implied a worldwide distribution of the species. Although Symbiotaphrinales has been treated as a member of Xylonomycetes in previous studies, it was shown to be phylogenetically, morphologically, and ecologically distinct. We, therefore, treated Symbiotaphrinales as Pezizomycotina incertae sedis.

A novel species of Tricholoma section Tricholoma, namely, T. olivaceonigrum, is described and illustrated based on samples found in an oak woods dominated by Quercus myrsinifolia, an evergreen oak, in Tottori Prefecture, western Japan. It is characterized by a conic-umbonate, dark-greenish olivaceous pileus with blackish innate fibrils; a whitish silky-fibrillose stipe, often faintly tinted pale yellow and with a narrowed subpointed base; subglobose to broadly elliptic spores; and fruiting in early winter. Phylogenetic analysis targeting the internal transcribed spacer region of the ribosomal RNA gene revealed that T. olivaceonigrum forms a well-supported clade sister to T. portentosum. Other morphologically and phylogenetically closely related species of the section Tricholoma are discussed.