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The metabolites of the genus Marasmius are diverse, showing good research prospects for finding new bioactive molecules. In order to explore the active metabolites of the fungi Marasmius berteroi, the deep chemical investigation on the bioactive compounds from its cultures was undertaken, which led to the isolation of three new naphthalene compounds dipolynaphthalenes A–B (1,2) and naphthone C (3), as well as 12 known compounds (4–15). Compounds 1, 2, and 4 are dimeric naphthalene compounds. Their structures were elucidated by MS, 1D and 2D NMR spectroscopic data, as well as ECD calculations. Compounds 2–4 and 7 exhibited acetylcholinesterase (AChE) inhibitory activities at the concentration of 50 μg/mL with inhibition ratios of 42.74%, 44.63%, 39.50% and 51.49%, respectively. Compounds 5 and 7,8 showed weak inhibitory activities towards two tumor cell lines, with IC50 of 0.10, 0.076 and 0.058 mM (K562) and 0.13, 0.18, and 0.15 mM (SGC-7901), respectively.

Background Plant-parasitic nematodes and herbivorous insects have a significant negative impact on global crop production. A successful approach to protect crops from these pests is the in planta expression of nematotoxic or entomotoxic proteins such as crystal proteins from Bacillus thuringiensis ( Bt ) or plant lectins. However, the efficacy of this approach is threatened by emergence of resistance in nematode and insect populations to these proteins. To solve this problem, novel nematotoxic and entomotoxic proteins are needed. During the last two decades, several cytoplasmic lectins from mushrooms with nematicidal and insecticidal activity have been characterized. In this study, we tested the potential of Marasmius oreades agglutinin (MOA) to furnish Arabidopsis plants with resistance towards three economically important crop pests: the two plant-parasitic nematodes Heterodera schachtii and Meloidogyne incognita and the herbivorous diamondback moth Plutella xylostella . Results The expression of MOA does not affect plant growth under axenic conditions which is an essential parameter in the engineering of genetically modified crops. The transgenic Arabidopsis lines showed nearly complete resistance to H. schachtii , in that the number of female and male nematodes per cm root was reduced by 86–91 % and 43–93 % compared to WT, respectively. M. incognita proved to be less susceptible to the MOA protein in that 18–25 % and 26–35 % less galls and nematode egg masses, respectively, were observed in the transgenic lines. Larvae of the herbivorous P. xylostella foraging on MOA-expression lines showed a lower relative mass gain (22–38 %) and survival rate (15–24 %) than those feeding on WT plants. Conclusions The results of our in planta experiments reveal a robust nematicidal and insecticidal activity of the fungal lectin MOA against important agricultural pests which may be exploited for crop protection.

Phylogenetic placement of the infrageneric section Hygrometrici (genus Marasmius sensu stricto) in prior molecular phylogenetic studies have been unresolved and problematical. Molecular analyses based on newly generated ribosomal nuc-LSU and 5.8S sequences resolve members of section Hygrometrici to the family Physalacriaceae. The new genus Cryptomarasmius is proposed to accommodate members of Marasmius section Hygrometrici. Fourteen species belonging to section Hygrometrici whose available type specimens bear morphological features corresponding to the new genus are formally combined in Cryptomarasmius. Taxonomic transfers are made only for taxa in which type specimens have been studied and/or representative material sequenced. Although other species placed in section Hygrometrici may belong in Cryptomarasmius, further transfers are not proposed until additional studies on type material are conducted.

Genetic variability can be generated by different mechanisms, and across the life cycle. Many basidiomycete fungi have an extended somatic stage, during which each cell carries two genetically distinct haploid nuclei (dikaryosis), resulting from fusion of two compatible monokaryotic individuals. Recent findings have revealed remarkable genome stability at the nucleotide level during dikaryotic growth in these organisms, but whether this pattern extends to mutations affecting large genomic regions remains unknown. Furthermore, despite high genome integrity during dikaryosis, basidiomycete populations are not devoid of genetic diversity, begging the question of when this diversity is introduced. Here, we used a Marasmius oreades fairy ring to investigate the rise of large-scale variants during mono- and dikaryosis. By separating the two nuclear genotypes from four fruiting bodies and generating complete genome assemblies, we gained access to investigate genomic changes of any size. We found that during dikaryotic growth in nature the genome stayed intact, but after separating the nucleotypes into monokaryons, a considerable amount of structural variation started to accumulate, driven to large extent by transposons. Transposon insertions were also found in monokaryotic single-meiospore isolates. Hence, we show that genome integrity in basidiomycetes can be interrupted during monokaryosis, leading to genomic rearrangements and increased activity of transposable elements.We suggest that genetic diversification is disproportionate between life cycle stages in mushroom-forming fungi, so that the short-lived monokaryotic growth stage is more prone to genetic changes than the dikaryotic stage.

An arthroconidial hyphomycete on living leaves of kudzu (Pueraria montana, Fabaceae), originally described by Sawada in 1959 as Ovularia puerariae, was rediscovered. This anamorph is connected to an unknown Marasmius teleomorph belonging to section Globulares, which develops on the same living leaves. Ultrastructure and LSU rDNA sequence analysis of the anamorph confirm this connection. The fungus does not have only a unique biology among agarics, comparable only to Mycena citricolor, but also has the potential for application as a control agent of kudzu. During comparison with similar anamorph genera, Illosporium graminicola was found to be a synonym for Beniowskia sphaeroidea.

A new mannose-recognizing lectin (MOL) was purified on an asialofetuin-column from fruiting bodies of Marasmius oreades grown in Japan. The lectin (MOA) from the fruiting bodies of the same fungi is well known to be a ribosome-inactivating type lectin that recognizes blood-group B sugar. However, in our preliminary investigation, MOA was not found in Japanese fruiting bodies of M. oreades , and instead, MOL was isolated. Gel filtration showed MOL is a homodimer noncovalently associated with two subunits of 13 kDa. The N-terminal sequence of MOL was blocked. The sequence of MOL was determined by cloning from cDNA and by protein sequencing of enzyme-digested peptides. The sequence shows mannose-binding motifs of bulb-type mannose-binding lectins from plants, and similarity to the sequences. Analyses of sugar-binding specificity by hemagglutination inhibition revealed the preference of MOL toward mannose and thyroglobulin, but asialofetuin was the strongest inhibitor of glycoproteins tested. Furthermore, glycan-array analysis showed that the specificity pattern of MOL was different from those of typical mannose-specific lectins. MOL preferred complex–type N-glycans rather than high-mannose N-glycans.

The aim of this study was to determine the element content of wild edible and inedible mushroom species ( Agaricus campestris , Armillaria ostoyae , Boletus reticulatus , Bondarzewia mesenterica , Bovistella utriformis , Cantharellus cibarius , Marasmius oreades , Megacollybia platyphylla , Meripilus giganteus , Neoboletus erythropus , Panellus stipticus , Phaeotremella foliacea , Pleurotus ostreatus , Podoscypha multizonata , Russula aurea , R. chloroides , R. virescens , T. versicolor , Trametes gibbose , and Trichaptum biforme ) collected from the Belgrad Forests and the Ilgaz Mountain National Park. Based on the results of elemental analyses, daily metal intake (DMI) and health risk index (HRI) values of edible mushrooms collected from both localities were also calculated. As, Cd, Cr, Se, P, Hg, Cu, Mn, Fe, Zn, Al, Ca, Mg, and K contents of mushrooms were in the ranges of 0.16–3.45, 0.09–2.4, 0.15–2.34, 0.3–8.13, 0.28–11.44, 14.03–37.81, 3.87–108.57, 6.18–149.77, 11.9–776.1, 5.4–317.4, 7.4–355.2, 15.4–3517.3, 266.0–2500.0, and 628.0–24083.0 mg/kg dry weight, respectively. As a result of the DMI and HRI analyses, Cu concentration of B. utriformis (DMI: 46.53 μg/kg body weight/serving, HRI: 1.16) and Cd concentrations of A. campestris (DMI: 0.49 μg/kg body weight/serving, HRI: 1.36), A. ostoyae (DMI: 1.03 μg/kg body weight/serving, HRI: 2.86), B. utriformis (DMI: 0.52 μg/kg body weight/serving, HRI: 1.44), and P. ostreatus (DMI: 0.45 μg/kg body weight/serving, HRI: 1.24) were found to exceed the legal limits determined by authorities. It was concluded that the species collected from the regions in question should be consumed in a controlled manner.

Unspecific peroxygenases (UPOs) are glycosylated enzymes that provide an efficient method for oxyfunctionalizing a variety of substrates using only hydrogen peroxide (H2O2) as the oxygen donor. However, their poor heterologous expression has hindered their practical application. Here, a novel UPO from Marasmius fiardii PR910 (MfiUPO) was identified and heterologously expressed in Pichia pastoris. By employing a two-copy expression cassette, the protein titer reached 1.18 g L−1 in a 5 L bioreactor, marking the highest record. The glycoprotein rMfiUPO exhibited a smeared band in the 40 to 55 kDa range and demonstrated hydroxylation, epoxidation and alcohol oxidation. Moreover, the peroxidative activity was enhanced by 150% after exposure to 50% (v/v) acetone for 40 h. A semi-preparative production of 4-OH-β-ionone on a 100 mL scale resulted in a 54.2% isolated yield with 95% purity. With its high expression level, rMfiUPO is a promising candidate as an excellent parental template for enhancing desirable traits such as increased stability and selectivity through directed evolution, thereby meeting the necessary criteria for practical application.

A novel laccase-producing white-rot fungus, Marasmius sp. BBKAV79 (Genbank Accession Number-KP455496, KP455497), was isolated and subjected to purification, characterization and dye decolorization study. The purified enzyme was obtained with a specific activity of 0.226 U mg −1 protein and a final yield of 13.5 %. The enzyme was found to be a monomeric protein with a molecular mass of ~75 kDa as estimated by non-denaturing polyacrylamide gel electrophoresis (PAGE) and further confirmed with zymogram analysis. The optimal pH and temperature of the laccase was recorded to be 5.5 and 40 °C, respectively. The metal ions Hg 2+ and Ag + were found to drastically inhibit the activity of laccase at the rate of 96.6 and 96.5 %, respectively. Nevertheless, Fe 3+ was found to inhibit laccase activity at 40 %. Phenylmethanesulfonyl fluoride (PMSF) strongly inhibited the laccase activity, and additives viz, sodium dodecyl sulfate (SDS), hydrogen peroxide (H 2 O 2 ) and sodium chloride (NaCl) were known to follow the earlier pattern of enzyme inhibition. The values of kinetic parameters K m and V max for purified laccase were noted at 3.03 mM and 5 μmol min −1 , respectively, for guaiacol as substrate. The textile dyes were decolorized at a range of 72–76 % and 88–93 % when treated with Marasmius sp. BBKAV79 and purified laccase, respectively. Based on the outcome of the present investigation, it could be, therefore, inferred that laccase isolated from Marasmius sp. BBKAV79 effectively decolorizes the textile dyes; however, the metal ions Hg 2+ , Ag + and Fe 3+ and agents like PMSF, SDS, H 2 O 2 and NaCl pose an effective inhibitory potential under specified physicochemical conditions.

Fully mycoheterotrophic (FMH) orchids rely entirely on mycorrhizal fungi for carbon and nutrients, with tropical Asian FMH orchids typically associating with saprotrophic fungi, though some known relationships also with ectomycorrhizal fungi, leaving much to learn about their fungal partners. Didymoplexis belongs to tribe Gastrodieae, which represents one of the largest fully mycoheterotrophic orchid lineages. Although mycorrhizal associations of its sister genus Gastrodia have been relatively well-studied, those of Didymoplexis remain largely unexplored. Here, we used molecular barcoding to analyze fungal associations and stable isotope analysis to elucidate the nutritional strategies of Didymoplexis micradenia , Didymoplexis pallens , and Didymoplexis siamensis in subtropical and tropical forests across Taiwan. In Didymoplexis pallens and Didymoplexis micradenia , most fungal partners were litter-decaying fungi ( Mycena , Clitocybula , Marasmius , Gymnopus ) with smaller contributions from ectomycorrhizal and rhizoctonia fungi. In Didymoplexis siamensis , ectomycorrhizal fungi dominated, particularly Sebacinales, however, with additional associations with wood-decaying Delicatula . The pattern of carbon and nitrogen isotope enrichments found for the three Didymoplexis species was in the typical range known for fully mycoheterotrophic orchids associated with litter- or wood-decaying fungi. 15 N enrichments of all investigated Didymoplexis species distinguished from fully mycoheterotrophic orchids associated with ectomycorrhizal fungi. Despite its ectomycorrhizal association, Didymoplexis siamensis was weakly enriched in 15 N and more enriched in 13 C than found for exclusively ectomycorrhizal fully mycoheterotrophic orchids. Thus, Didymoplexis siamensis covered its carbon and nitrogen demand obviously through the additional association with wood-decaying Delicatula . These findings enhance our understanding of the diverse fungal associations and physiological ecology of Didymoplexis species in subtropical and tropical ecosystems.