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1.
J Mech Behav Biomed Mater ; 150: 106282, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38118375

ABSTRACT

Despite the promising applications of hydrogels, their poor mechanical properties still greatly limit their further applications. To improve the mechanical properties of hydrogels, various strategies have been proposed. Hydrogels with nanoparticle-crosslinked polymer networks show excellent toughness, self-recovery, and other advantages, and thus have great prospects for use in tissue engineering, artificial muscles, flexible electronics, and other fields. There have been experimental and theoretical studies of its damage. However, the underlying microscale physical mechanisms have not been fully elucidated. Herein, we established a physics-based constitutive model to describe the mechanical behavior of nanoparticle-crosslinked hydrogels under cyclic loading. The deformation-induced damage and the rate-dependent damage were explained by the network alteration and kinetics of chain dissociation/association, respectively. The kinetics dissociation/association theory was modified considering the polymer chains that wind around nanoparticles. The Mullins stress softening and recovery during cyclic loading were described. Cyclic loading tests on nanoparticle-crosslinked hydrogels were carried out to verify the proposed constitutive model. It is demonstrated that the model can well describe the mechanical behavior of nanoparticle-crosslinked hydrogels during cyclic loading.


Subject(s)
Hydrogels , Nanoparticles , Tissue Engineering , Polymers , Physics
2.
Front Nutr ; 10: 1168025, 2023.
Article in English | MEDLINE | ID: mdl-37457983

ABSTRACT

Introduction: Low temperature is the most common method used to maintain the freshness of Phlebopus portentosus during long-distance transportation. However, there is no information regarding the nutritional changes that occur in P. portentosus preserved postharvest in low temperature. Methods: In this study, the changes in flavor quality and bioactive components in fruiting bodies stored at 4 °C for different storage periods were determined through LC/MS and GC/MS analyses. Sampling was performed at 0, 3, 5, 7, and 13 days storage. Results and Discussion: Based on the results, the metabolites present in caps and stipes were different at the same period and significantly different after 7 days of storage. A total of 583 and 500 different metabolites were detected in caps and stipes, respectively, and were mainly lipids and lipid-like molecules, organic acids and derivatives, organic oxygen compounds and others. Except for prenol lipids and nucleotides, the expression levels of most metabolites increased with longer storage time. In addition, geosmin was identified as the major contributor to earthy-musty odors, and the level of geosmin was increased when the storage time was short. Conclusion: The variations in these metabolites might cause changes in flavor quality and bioactive components in P. portentosus. Variations in these metabolites were thoroughly analyzed, and the results revealed how storage processes affect the postharvest quality of P. portentosus for the first time.

3.
Microbiol Spectr ; 11(4): e0282322, 2023 08 17.
Article in English | MEDLINE | ID: mdl-37347174

ABSTRACT

Lentinula edodes is one of the most widely cultivated edible mushrooms in the world. When cultivated in sawdust, the surface mycelium of L. edodes needs a long postripening stage wherein it forms a brown film (BF) by secreting and accumulating pigments. BF formation is critical for the high quality and yield of fruiting bodies. Protein lysine acetylation (KAC) is an important post-translational modification that regulates growth and development. Previous studies have shown that deacetylase levels are significantly increased during BF formation in the postripening stage of L. edodes. The aim of this study was to assess the role of protein acetylation during BF formation. To this end, we compared the acetylome of L. edodes mycelia before and after BF formation using anti-acetyl antibody-based label-free quantitative proteomics. We identified 5,613 acetylation sites in 1,991 proteins, and quantitative information was available for 4,848 of these sites in 1,815 proteins. Comparative acetylome analysis showed that the modification of 699 sites increased and that of 562 sites decreased during BF formation. Bioinformatics analysis of the differentially acetylated proteins showed significant enrichment in the tricarboxylic acid (TCA) cycle and proteasome pathways. Furthermore, functional assays showed that BF formation is associated with significant changes in the activities of proteasome, citrate synthase, and isocitrate dehydrogenase. Consistent with this hypothesis, the lysine deacetylase inhibitor trichostatin (TSA) delayed autophagy and BF formation in L. edodes. Taken together, KAC and autophagy play important roles in the mycelial BF formation and postripening stage of L. edodes. IMPORTANCE Mycelial BF formation and postripening of L. edodes affects the quality and quantity of its edible fruiting bodies. In this study, we explored the role of protein KAC in this biological process, with the aim of optimizing the cultivation and yield of L. edodes.


Subject(s)
Shiitake Mushrooms , Shiitake Mushrooms/metabolism , Lysine/metabolism , Acetylation , Proteasome Endopeptidase Complex/metabolism , Mycelium , Autophagy
4.
Bioresour Technol ; 376: 128888, 2023 May.
Article in English | MEDLINE | ID: mdl-36925076

ABSTRACT

Low ambient temperature poses a challenge for rice straw-silage processing in cold climate regions, as cold limits enzyme and microbial activity in silages. Here, a novel cold-active cellobiohydrolase (VvCBHI-I) was isolated from Volvariella volvacea, which exhibited outstanding cellobiohydrolase activity at 10-30 °C. The crude cellulase complex in the VvCBHI-I-expressing transformant T1 retained 50% relative activity at 10 °C, while the wildtype Trichoderma reesei showed <5% of the activity. VvCBHI-I greatly improved the saccharification efficiency of the cellulase complex with pretreated rice straw as substrate at 10 °C. In rice straw silage, pH (<4.5) and lactic acid content (>4.6%) remained stable after 15-day ensiling with the cellulase complex from T1 and Lactobacillus plantarum. Moreover, the proportions of cellulose and hemicellulose decreased to 29.84% ± 0.15% and 21.25% ± 0.26% of the dried material. This demonstrates the crucial potential of mushroom-derived cold-active cellobiohydrolases in successful ensiling in cold regions.


Subject(s)
Agaricales , Cellulase , Cellulase/metabolism , Cellulose 1,4-beta-Cellobiosidase , Temperature , Fermentation , Silage/analysis , Agaricales/metabolism
5.
Microbiol Spectr ; : e0527222, 2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36916925

ABSTRACT

Fruiting body formation is the most important developmental event in the edible mushroom life cycle; however, the genetic regulation of this process is not well understood. Pleurotus eryngii is a widely cultivated mushroom with high economic value. The mating of two monokaryons carrying compatible A and B mating-type genes is required for the development of fruiting bodies in P. eryngii. In this study, we showed that the monokaryons of P. eryngii transformed with compatible homeodomain (A mating type) and pheromone (B mating type) genes can complete fruiting body development but cannot form basidiospores. Transcriptional analyses revealed that expression of endogenous homeodomain and pheromone receptor genes and mating signaling pathways were activated by transferred homeodomain and pheromone genes in the transformants. Our findings provide a novel model for studying fruiting body development, which may accelerate the genetic breeding of edible mushrooms in the future. IMPORTANCE Fruiting bodies of edible mushrooms have high nutritional value. However, the fruiting body development of mushrooms is not well understood, and thus, many wild edible mushrooms of economic importance cannot be cultivated artificially. Moreover, variety among cultivatable mushrooms has improved marginally. Under natural conditions, fruiting body development can be initiated only in a dikaryon, the sexual mycelium obtained from mating two compatible monokaryons. The present work showed induction of fruiting body development in Pleurotus eryngii monokaryons by genetic manipulation. Gene expression analyses revealed key genes and signaling pathways involved in the fruiting body development of P. eryngii.

6.
Front Microbiol ; 13: 811673, 2022.
Article in English | MEDLINE | ID: mdl-35283832

ABSTRACT

Lentinula edodes (Berk.) Pegler, the shiitake mushroom, is one of the most important mushrooms in the global mushroom industry. Although mycelium post ripeness and brown film (BF) formation are crucial for fruiting body initiation, the underlying molecular mechanisms of BF formation are largely unknown. In this study, proteomic quantification (relative and absolute) and metabolomic profiling of L. edodes were performed using isobaric tags and gas chromatography-mass spectroscopy, respectively. A total of 2,474 proteins were identified, which included 239 differentially expressed proteins. Notably, several proteins associated with autophagy were upregulated, including RPD3, TOR1, VAC8, VPS1, and VPS27. Transmission electron microscopy also indicated that autophagy occurred in post ripeness and BF formation. In time-dependent analysis of the metabolome, metabolites associated with oxidative stress and autophagy changed significantly, including mannitol, trehalose, myo-inositol, glucose, leucine, valine, glutamine, and 4-aminobutyric acid. Thus, oxidative stress and autophagy were important processes in post ripeness and BF formation in L. edodes, and new insights were gained into molecular mechanisms at proteome and metabolome levels.

7.
Mitochondrial DNA B Resour ; 7(1): 286-288, 2022.
Article in English | MEDLINE | ID: mdl-35111939

ABSTRACT

The culinary-medicinal mushroom Grifola frondosa is widely cultivated in East Asia. In this study, the complete mitochondrial genome of G. frondosa was determined using Illumina sequencing. The circular molecule was 197,486 bp in length with a content of 25.01% GC, which was one of the largest mitochondrial genomes in the order Polyporales. A total of 39 known genes encoding 13 common mitochondrial genes, 24 tRNA genes, 1 ribosomal protein s3 gene (rps3), and 1 DNA polymerase gene (dpo) were predicted in this genome. The phylogenetic analysis showed that G. frondosa clustered together with Sparassis crispa, Laetiporus sulphureus, Wolfiporia cocos, and Taiwanofungus camphoratus. The complete mitochondrial genome reported here may provide new insight into genetic information and evolution for further studies.

8.
Eur J Histochem ; 64(s2)2020 Dec 02.
Article in English | MEDLINE | ID: mdl-33334091

ABSTRACT

Our previous study documented that melatonin (MLT) induced the osteogenic differentiation of mesenchymal stem cells (MSCs) and promoted the healing of femoral fractures in rats via the neuropeptide Y (NPY)/neuropeptide Y1 receptor (NPY1R) signaling pathway. MLT treatment upregulated the expression of the zinc uptake transporter zinc transporter 1 (Zip1) in nerve cells. Prior research demonstrated that oral zinc upregulated NPY expression. MSCs were isolated from rat bone marrow and identified using flow cytometry in our study. The results showed that MLT treatment upregulated NPY and NPY1R levels in MSCs with osteogenic differentiation, which was accompanied by upregulated Zip1 expression. However, the MLT-induced osteogenic differentiation of MSCs was reversed after interference of Zip1 expression. It was confirmed by the decreased alkaline phosphatase (ALP) level; downregulated activities of type I collagen α1 chain (COL1A1), osteocalcin (OCN), runt-related transcription factor 2 (Runx2) and ALP; and reduced mineralized nodule formation. MLT promoted fracture healing in rats with femoral fracture, which was accompanied by increased expression of NPY and NPY1R and significantly increased expression of Zip1. In contrast, the silencing of Zip1 expression reversed MLT-mediated fracture healing. In summary, Zip1 participated in the regulation of the NPY/NPY1R signaling pathway via MLT to promote the osteogenic differentiation of MSCs and fracture healing.


Subject(s)
Cation Transport Proteins/metabolism , Femoral Fractures/drug therapy , Melatonin/therapeutic use , Neuropeptide Y/metabolism , Animals , Cell Differentiation/drug effects , Femoral Fractures/metabolism , Male , Mesenchymal Stem Cells/metabolism , Rats, Sprague-Dawley , Receptors, G-Protein-Coupled/metabolism , Receptors, Neuropeptide/metabolism , Signal Transduction/drug effects , Up-Regulation/drug effects , Wound Healing/drug effects
9.
Front Microbiol ; 11: 523593, 2020.
Article in English | MEDLINE | ID: mdl-33042047

ABSTRACT

In Volvariella volvacea, an important species of edible mushroom, cryogenic autolysis is a typical phenomenon that occurs during abnormal metabolism. Analysis of gene expression profiling and qPCR showed that chilling stress (CS) significantly and continuously upregulated only one type of Argonaute in V. volvacea, i.e., VvAgo1. Structural and evolutionary analysis revealed that VvAgo1 belongs to the Ago-like family, and its evolution has involved gene duplication, subsequent gene loss, and purifying selection. Analysis of its interaction network and expression suggested that CS triggers VvAgo1-mediated miRNA-like RNA (milRNA) biogenesis in V. volvacea V23 but not in VH3 (a composite mutant strain from V23 with improved CS resistance). Small RNA sequencing and qPCR analysis confirmed that CS triggered the increased milRNA expression in V23 and not in VH3. The predicted target genes of the increased milRNAs were enriched in several pathways, such as signal transduction and ubiquitination. Heatmap analysis showed that CS altered the expression profile of milRNAs with their target genes related to signal transduction and ubiquitination in V23. Combined analysis of transcriptome and proteome data confirmed that most of the target genes of the increased milRNAs were not translated into proteins. Our observations indicate that CS might trigger VvAgo1-mediated RNAi to facilitate the cryogenic autolysis of V. volvacea.

10.
Fungal Genet Biol ; 142: 103415, 2020 09.
Article in English | MEDLINE | ID: mdl-32497577

ABSTRACT

SNF1/AMPK protein kinases play important roles in fungal development and activation of catabolite-repressed genes. In this study, we characterized the role of SNF1 ortholog in Cordyceps militaris (CmSnf1). The vegetative growth of a CmSnf1 deletion mutant was (ΔCmSnf1) reduced by 42.2% with arabinose as a sole carbon source. Most strikingly, the ΔCmSnf1 produced only a few conidia and exhibited delayed conidial germination. We found that CmSnf1 was necessary for mycelium to penetrate the insect cuticle to form the fruiting body on silkworm pupae, consistent with the down-regulation of chitinase- and protease-encoding genes in ΔCmSnf1. However, cordycepin content increased by more than 7 times in culture supernatants. Correspondingly, the relative expression levels of cordycepin gene cluster members were also elevated. In particular, the expression of cns4 associated with cordycepin transfer was up-regulated >10-fold. Furthermore, transcriptional analysis showed that CmSnf1 regulated the expression of genes involved in cell autophagy and oxidative stress tolerance. We speculated that under environmental stress, both the ATG and SNF1 pathways might collaborate to sustain adverse environments. Our study provides an initial framework to probe the diverse function and regulation of CmSnf1 in C. militaris, which will shed more light on the direction of molecular improvement of medicinal fungi.


Subject(s)
Cordyceps/genetics , Mycelium/genetics , Protein Serine-Threonine Kinases/genetics , Stress, Physiological/genetics , Carbon/metabolism , Cordyceps/pathogenicity , Fruiting Bodies, Fungal/genetics , Fruiting Bodies, Fungal/metabolism , Genome, Fungal/genetics
11.
J Agric Food Chem ; 68(29): 7581-7590, 2020 Jul 22.
Article in English | MEDLINE | ID: mdl-32579349

ABSTRACT

The grain size and shape of rice are limited by the growth of the spikelet hulls and are important selective target during domestication and breeding. In this study, we identified a glycine- and proline-rich protein (OsGPRP3), which belongs to a conserved family rarely studied. We found that OsGPRP3 was highly expressed in the seed at 10 days after pollination (DAP) using qRT-PCR, pOsGPRP3::GUS and in situ hybridization. Knockout and knockdown of OsGPRP3 led to significant decrease of 1000-grain weight, grain width, and grain thickness. We further found that the content of storage protein and total lipid were decreased in osgprp3 lines. In particular, the contents of C14:0 (myristic acid), C16:0 (palmitic acid), C18:1 (oleic acid), and C18:2 (linoleic acid) were reduced in osgprp3 lines. Cytological experiments revealed that the cell width of spikelet hull in osgprp3 lines was significantly reduced than that in WT. Taken together, our results reveal that OsGPRP3 regulates the grain size and shape of rice by influencing the cell width of spikelet hulls and the accumulation of storage protein and lipids.


Subject(s)
Oryza/metabolism , Plant Proteins/metabolism , Seeds/growth & development , Gene Expression Regulation, Plant , Glycine/metabolism , Lipid Metabolism , Lipids/chemistry , Oryza/chemistry , Oryza/genetics , Oryza/growth & development , Plant Proteins/genetics , Plants, Genetically Modified/chemistry , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Plants, Genetically Modified/metabolism , Proline/metabolism , Seeds/chemistry , Seeds/genetics , Seeds/metabolism
12.
ACS Omega ; 5(13): 7567-7575, 2020 Apr 07.
Article in English | MEDLINE | ID: mdl-32280900

ABSTRACT

The brown film (BF) of Lentinula edodes mycelium has been reported to exert biological activities during mushroom cultivation; however, to date, there is limited information on its chemical composition. In this study, untargeted metabolomics analysis was performed via liquid chromatography-mass spectrometry (LC-MS), and the results were used to screen the antimicrobial compounds. A total of 236 differential metabolites were found among the BF stages compared with the white hyphal stage. Among them, five important antimicrobial metabolites related to antimicrobial activities, namely, 6-deoxyerythronolide B, tanikolide, hydroxyanthraquinone, benzylideneacetone, and 9-OxooTrE, were present at high levels in the BF samples. The score plots of the principal component analysis indicated that the samples from four time points could be classified into two groups. This study provided a comprehensive profile of the antimicrobial compounds produced during BF formation and partly clarified the antibacterial and antifungal mechanism of the BF of L. edodes mycelium.

13.
J Microbiol Methods ; 171: 105878, 2020 04.
Article in English | MEDLINE | ID: mdl-32092329

ABSTRACT

Using the carboxin resistance gene from Pleurotus eryngii as a selective marker, we introduced foreign DNA into the arthroconidia of Hypsizygus marmoreus through Agrobacterium-mediated transformation. The function of the exogenous GUS (ß-glucuronidase) gene driven by the CaMV35S promoter was detected in the transformants.


Subject(s)
Agaricales/genetics , Agrobacterium/genetics , Glucuronidase/genetics , Spores, Fungal/genetics , Transformation, Genetic/genetics , Agaricales/metabolism , Carboxin/pharmacology , Drug Resistance, Fungal/genetics , Fungicides, Industrial/pharmacology , Plasmids/genetics , Pleurotus/genetics , Promoter Regions, Genetic/genetics
14.
J Proteomics ; 215: 103668, 2020 03 20.
Article in English | MEDLINE | ID: mdl-31982547

ABSTRACT

In Volvariella volvacea, an important edible mushroom species, cryogenic autolysis is a typical part of abnormal metabolism; however, the underlying mechanisms remain unclear. Ubiquitylome analysis revealed that chilling stress (CS) affected protein translation and degradation by ubiquitination. Comparative proteomics analysis showed that CS downregulated protein expression in V. volvacea V23 instead of VH3 (improved chilling stress resistance strain). The integrative ubiquitylome, proteomics, and transcriptome analyses indicated that CS reduced protein translation by the ubiquitination of ribosomal proteins. An activity assay of the 20S proteasome showed that CS decreased the degradation efficiency of the ubiquitin-proteasome system. UBEV2, one type of ubiquitin-conjugating enzyme E2 (UBE2) in V. volvacea, was upregulated after cold stress treatment using western blot analysis. GST pull-down experiments of UBEV2 provided evidence that CS affected protein translation by the ubiquitination of ribosomal proteins. Co-IP experiments confirmed that UBEV2 bound to the ubiquitinated SSB2, a ribosome-associated molecular chaperone. An anti-freezing experiment demonstrated that the UBE2 inhibitor could improve the cold stress resistance of V. volvacea. Our observations revealed that CS triggered ubiquitination-mediated autolysis associated with a decrease in protein translation and highlighted the mechanistic role of UBEV2 in facilitating cryogenic autolysis in V. volvacea. SIGNIFICANCE: Volvariella volvacea, the edible straw mushroom, is a highly nutritious food source widely cultivated on a commercial scale in tropical and subtropical regions. The challenges associated with the cryogenic autolysis preservation of V. volvacea have limited its marketability. This issue of cryogenic autolysis is both an interesting scientific problem to solve and a practical economic matter. Integrative ubiquitylome, proteomics, and transcriptome analyses, together with GST pulldown and Co-IP experiments, indicated that chilling stress reduced protein translation by the ubiquitination of ribosomal proteins in V. volvacea. This study significantly contributes to our understanding of ubiquitination-mediated autolysis associated with a decrease in protein translation in V. volvacea. Our data highlight the mechanistic role of UBEV2 in facilitating the cryogenic autolysis of V. volvacea. We provided a new idea for the preservation of V. volvacea by inhibiting UBEV2 to increase its marketability.


Subject(s)
Volvariella , Agaricales , Protein Biosynthesis , Ribosomal Proteins , Ubiquitination , Volvariella/genetics
15.
Cell Biol Int ; 44(2): 402-411, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31535749

ABSTRACT

Melatonin has been reported to participate in bone metabolism in recent studies. However, the underlying mechanism in melatonin-mediated osteoblastic differentiation remains largely unknown. The aim of this study is to investigate the role of melatonin in osteoblastic differentiation. In the present study, additional melatonin significantly promoted osteoblastic differentiation of MC3T3-E1 cells as evidenced by increased messenger RNA (mRNA) levels of osteogenic markers, alkaline phosphatase (ALP), collagen type I α1 chain, osteocalcin, and runt-related transcription factor 2 (Runx2). It was noteworthy that the expression level of platelet-derived growth factor subunit B (PDGFB) and content of its homodimer PDGF-BB were remarkably increased after melatonin administration. Moreover, the mRNA levels of phosphorylated PDGFRß (PDGF receptor ß) and Akt, a serine/threonine-specific protein kinase, were significantly upregulated in melatonin-treated MC3T3-E1 cells determined by a real-time polymerase chain reaction. Besides, by performing alizarin red staining, osteoblastic differentiation of MC3T3-E1 cells was conspicuously promoted by melatonin, which could be partially attenuated by crenolanib, a PDGFR inhibitor. Similarly, results from immunofluorescence and western blot assay showed that melatonin-induced upregulation of Runx2 and phosphorylated Akt was suppressed by crenolanib. Akt inhibition by MK-2206 also suppressed osteoblastic differentiation. Furthermore, by in vivo assay, additional melatonin promoted osteoblastic differentiation in mice with femoral fracture, and obvious callus formation was observed in melatonin-treated mice 5 weeks after fracture. Melatonin supplement also inhibited osteoclastic differentiation in mice. All statistical analysis was performed using GraphPad Prism and a P < 0.05 was deemed to be significant. To summarize, we demonstrate that melatonin promotes osteoblastic differentiation in MC3T3-E1 cells and enhances fracture healing in mouse femoral fracture model and regulates PDGF/AKT signaling pathway.


Subject(s)
Antioxidants/pharmacology , Cell Differentiation , Melatonin/pharmacology , Osteoblasts/cytology , Osteogenesis , Platelet-Derived Growth Factor/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Alkaline Phosphatase/metabolism , Animals , Cell Proliferation , Cells, Cultured , Male , Mice , Mice, Inbred C57BL , Osteoblasts/drug effects , Osteoblasts/metabolism , Phosphorylation , Platelet-Derived Growth Factor/genetics , Proto-Oncogene Proteins c-akt/genetics , Signal Transduction
16.
Int J Med Mushrooms ; 21(12): 1223-1239, 2019.
Article in English | MEDLINE | ID: mdl-32464014

ABSTRACT

Large numbers of DNA sequences deposited in the International Nucleotide Sequence Databases (INSD) are erroneously annotated. The erroneous information may lead to misleading conclusions or cause great economic losses to farmers. Lentinus edodes (= Lentinula edodes (Berk.) Pegler) is one of the most important and popular culinary-medicinal mushrooms with a high nutritional value. In this study, experimental and in silico methods were used to correct the sequences annotated as L. edodes in the INSD. A total of 3,426 nucleotide entries were retrieved from public databases, including 140 different types of genetic sequences. Excluding 1,893 genome sequences, the most abundant signatures represented by ITS (258) and IGS1 (259) sequences accounted for 33.23% of the total entries. A total of 3,058 sequences were annotated correctly, 350 were indeterminate, and 18 were annotated erroneously based on the two methods. Correction of sequences will be beneficial for species identification and annotation. Phylogenic analysis based on ITS sequences suggested that L. edodes segregate in four clades in the tree based on ITS sequences. The isolates from China were distributed into two clades. In L. edodes, the intraspecific variation of the ITS2 sequences was much higher than that of the ITS1 sequences. In addition, the genetic diversity of the L. edodes sequences from China was much higher than that of any other regions included in this study. The northwest and southwest regions of China were L. edodes diversity centers.


Subject(s)
Base Sequence , Databases, Nucleic Acid , Molecular Sequence Annotation/methods , Sequence Analysis, DNA/methods , Shiitake Mushrooms/genetics , China , DNA, Ribosomal Spacer , Genetic Variation , Reproducibility of Results , Shiitake Mushrooms/classification
17.
PLoS One ; 13(10): e0206428, 2018.
Article in English | MEDLINE | ID: mdl-30359454

ABSTRACT

The nuclear ribosomal DNA internal transcribed spacer (ITS) has been widely used to assess the fungal composition in different environments by deep sequencing. To evaluate the ITS in the analysis of fungal diversity, comparisons of the clustering and taxonomy generated by sequencing with different portions of the whole fragment were conducted in this study. For a total of 83,120 full-length ITS sequences obtained from the UNITE database, it was found that, on average, ITS1 varied more than ITS2 within the kingdom Fungi; this variation included length and GC content variations and polymorphisms, with some polymorphisms specific to particular fungal groups. The taxonomic accuracy for ITS was higher than that for ITS1 or ITS2. The commonly used operational taxonomic unit (OTU) for evaluating fungal diversity and richness assigned several species to a single OTU even with clustering at 99.00% sequence similarity. The clustering and taxonomic capacities did not differ between ITS1 and ITS2. However, the OTU commonality between ITS1 and ITS2 was very low. To test this observation further, 219,741 pyrosequencing reads, including 39,840 full-length ITS sequences, were obtained from 10 soil samples and were clustered into OTUs. The pyrosequencing results agreed with the results of the in silico analysis. ITS1 might overestimate the fungal diversity and richness. Analyses using ITS, ITS1 and ITS2 yielded several different taxa, and the taxonomic preferences for ITS and ITS2 were similar. The results demonstrated that ITS2 alone might be a more suitable marker for revealing the operational taxonomic richness and taxonomy specifics of fungal communities when the full-length ITS is not available.


Subject(s)
DNA, Fungal/chemistry , DNA, Ribosomal Spacer/chemistry , Genetic Variation , High-Throughput Nucleotide Sequencing , Computer Simulation , Databases, Nucleic Acid
18.
J Microbiol Methods ; 152: 7-9, 2018 09.
Article in English | MEDLINE | ID: mdl-30017848

ABSTRACT

We introduced a site-directed mutation in the sdi1 gene and used it as a selective marker for the polyethylene glycol-mediated transformation of Pleurotus eryngii monokaryon protoplasts. The transformants displayed obvious and stable resistance to the fungicide carboxin indicating that the mutant Pesdi1 gene is an efficient selective marker.


Subject(s)
Biomarkers , Fungal Proteins/genetics , Genetic Markers , Pleurotus/genetics , Transformation, Genetic , Carboxin/pharmacology , Fungicides, Industrial , Genes, Fungal , Genetic Vectors , Histone Deacetylases/genetics , Mutagenesis, Site-Directed , Polyethylene Glycols , Protoplasts , Repressor Proteins/genetics
19.
Mitochondrial DNA B Resour ; 3(2): 1241-1243, 2018 Oct 30.
Article in English | MEDLINE | ID: mdl-33474477

ABSTRACT

The complete mitochondrial genome of the edible fungus Hypsizygus marmoreus was published in this paper. It was determined using Pacbio and Illumina sequencing. The complete mitochondrial DNA (mtDNA) is 106,417 bp in length with a GC content of 31.74%, which was the fourth large mitogenome in Agaricales. The circular mitogenome encoded 67 protein-coding genes and one ribosomal RNAs (rns). Among these genes, 13 conserved protein-coding genes were determined in the genome, including 6 subunits of NAD dehydrogenase (nad1-4, 4L and 6), three cytochrome oxidases (cox1-3), one apocytochrome b (cob) and three ATP synthases (atp6, apt 8 and apt 9). The phylogenic analysis confirmed that H. marmoreus (Lyophyllaceae) clustered together with Tricholoma matsutake (Tricholomataceae).

20.
J Chem Theory Comput ; 13(8): 3706-3714, 2017 Aug 08.
Article in English | MEDLINE | ID: mdl-28682610

ABSTRACT

Graphene is a one-atom thick layer of carbon atoms arranged in a hexagonal pattern, which makes it the strongest material in the world. The Tersoff potential is a suitable potential for simulating the mechanical behavior of the complex covalently bonded system of graphene. In this paper, we describe a new coarse-grained (CG) potential, TersoffCG, which is based on the function form of the Tersoff potential. The TersoffCG applies to a CG model of graphene that uses the same hexagonal pattern as the atomistic model. The parameters of the TersoffCG potential are determined using structural feature and potential-energy fitting between the CG model and the atomic model. The modeling process of graphene is highly simplified using the present CG model as it avoids the necessity to define bonds/angles/dihedrals connectivity. What is more, the present CG model provides a new perspective of coarse-graining scheme for crystal structures of nanomaterials. The structural changes and mechanical properties of multilayer graphene were calculated using the new potential. Furthermore, a CG model of a graphene aerogel was built in a specific form of assembly. The chemical bonding in the joints of graphene-aerogel forms automatically during the energy relaxation process. The compressive and recover test of the graphene aerogel was reproduced to study its high elasticity. Our computational examples show that the TersoffCG potential can be used for simulations of graphene and its assemblies, which have many applications in areas of environmental protection, aerospace engineering, and others.

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