Macrosynteny analysis between Lentinula edodes and Lentinula novae-zelandiae reveals signals of domestication in Lentinula edodes.

The basidiomycete fungus Lentinula novae-zelandiae is endemic to New Zealand and is a sister taxon to Lentinula edodes, the second most cultivated mushroom in the world. To explore the biology of this organism, a high-quality chromosome level reference genome of L. novae-zelandiae was produced. Macrosyntenic comparisons between the genome assembly of L. novae-zelandiae, L. edodes and a set of three genome assemblies of diverse species from the Agaricomycota reveal a high degree of macrosyntenic restructuring within L. edodes consistent with signal of domestication. These results show L. edodes has undergone significant genomic change during the course of its evolutionary history, likely a result of its cultivation and domestication over the last 1000 years.

Nutritional analysis and molecular characterization of hybrid mushrooms developed through intergeneric protoplast fusion between Pleurotus sajor-caju and Calocybe indica with the purpose to achieve improved strains.

Two edible mushrooms Calocybe indica and Pleurotus sajor-caju were chosen as parent strains in this study to approach the concept of hybridization through the protoplast fusion technique. Protoplast fusion in presence of polyethylene glycol (PEG) was conducted between the parent strains and by further double selection screening method, six somatic hybrid lines were developed. Those fruit bodies of the hybrid lines showed phenotypic resemblance with Pleurotus sajor-caju when grown on paddy straw under favorable conditions. The hybridity of the newly developed somatic hybrid strains was established by barrage reaction, morphological traits, fruitbody parameter and, inter single sequence repeat (ISSR) profiling. One-way analysis of variance (ANOVA) was used for the analysis of phenotypic data of hybrid lines and parents. Five ISSR primers were used to generate 51 amplified DNA fragments ranged between 250 and 3000 bp in size in six hybrids and two parents with 90.19% polymorphism. Some of the hybrids contain some non-parental bands which indicate that recombination might happen in the hybrid genome hence confirming the hybridity of newly developed strains. The dendrogram was created using the Average Linkage (Between Groups) method based on ISSR profiling and genetic distance between parent-hybrids and hybrid-hybrid was analyzed by Jaccard's proximity matrix. A definite improvement in nutritional properties and biological activity was observed in the study. Due to ease in their cultivation, it can play a significant role in the rural economic development.

Comparative transcriptome analysis identified candidate genes involved in mycelium browning in Lentinula edodes.

BACKGROUND: Lentinula edodes is one of the most popular edible mushroom species in the world and contains useful medicinal components, such as lentinan. The light-induced formation of brown film on the vegetative mycelial tissues of L. edodes is an important process for ensuring the quantity and quality of this edible mushroom. To understand the molecular mechanisms underlying this critical developmental process in L. edodes, we characterized the morphological phenotypic changes in a strain, Chamaram, associated with abnormal brown film formation and compared its genome-wide transcriptional features. RESULTS: In the present study, we performed genome-wide transcriptome analyses of different vegetative mycelium growth phenotypes, namely, early white, normal brown, and defective dark yellow partial brown films phenotypes which were exposed to different light conditions. The analysis revealed the identification of clusters of genes specific to the light-induced brown film phenotypes. These genes were significantly associated with light sensing via photoreceptors such as FMN- and FAD-bindings, signal transduction by kinases and GPCRs, melanogenesis via activation of tyrosinases, and cell wall degradation by glucanases, chitinases, and laccases, which suggests these processes are involved in the formation of mycelial browning in L. edodes. Interestingly, hydrophobin genes such as SC1 and SC3 exhibited divergent expression levels in the normal and abnormal brown mycelial films, indicating the ability of these genes to act in fruiting body initiation and formation of dikaryotic mycelia. Furthermore, we identified the up-regulation of glycoside hydrolase domain-containing genes in the normal brown film but not in the abnormal film phenotype, suggesting that cell wall degradation in the normal brown film phenotype is crucial in the developmental processes related to the initiation and formation of fruiting bodies. CONCLUSIONS: This study systematically analysed the expression patterns of light-induced browning-related genes in L. edodes. Our findings provide information for further investigations of browning formation mechanisms in L. edodes and a foundation for future L. edodes breeding.

Genomics and Development of Lentinus tigrinus: A White-Rot Wood-Decaying Mushroom with Dimorphic Fruiting Bodies.

Lentinus tigrinus is a species of wood-decaying fungi (Polyporales) that has an agaricoid form (a gilled mushroom) and a secotioid form (puffball-like, with enclosed spore-bearing structures). Previous studies suggested that the secotioid form is conferred by a recessive allele of a single locus. We sequenced the genomes of one agaricoid (Aga) strain and one secotioid (Sec) strain (39.53-39.88 Mb, with 15,581-15,380 genes, respectively). We mated the Sec and Aga monokaryons, genotyped the progeny, and performed bulked segregant analysis (BSA). We also fruited three Sec/Sec and three Aga/Aga dikaryons, and sampled transcriptomes at four developmental stages. Using BSA, we identified 105 top candidate genes with nonsynonymous SNPs that cosegregate with fruiting body phenotype. Transcriptome analyses of Sec/Sec versus Aga/Aga dikaryons identified 907 differentially expressed genes (DEGs) along four developmental stages. On the basis of BSA and DEGs, the top 25 candidate genes related to fruiting body development span 1.5 Mb (4% of the genome), possibly on a single chromosome, although the precise locus that controls the secotioid phenotype is unresolved. The top candidates include genes encoding a cytochrome P450 and an ATP-dependent RNA helicase, which may play a role in development, based on studies in other fungi.

Agrobacterium tumefaciens-Mediated Transformation of the King Tuber Medicinal Mushroom Lentinus tuber-regium (Agaricomycetes).

Lentinus tuber-regium is a sclerotium-forming basidiomycetous mushroom. It has increasingly aroused people's attention for its medicinal effects. In this study, we investigated the applicability of the Agrobacterium tume-faciens-mediated transformation (ATMT) method in L. tuber-regium. A. tumefaciens strain GV 3101 harboring the vector pPEH was used to transform the mycelium of L. tuber-regium strain ACCC50657. The genes for hygromycin B phosphotransferase (hph) and enhanced green fluorescent protein (egfp) under the control of the glyceraldehyde-3-phosphate dehydrogenase (gpd) gene promoter of Pleurotus ostreatus were employed as the selection marker and reporter gene, respectively. The optimal cocultivation temperature and time for transformation were 3 days and 4 days at 25°C and 20°C, respectively. Southern blot analysis showed the variation in the copy number and position of hph, which indicated random integration of hph. Polymerase chain reaction and fluorescence microscopy indicated that the P. ostreatus gpd promoter can drive the fused hph-egfp gene expression in L. tuber-regium. This is the first report that the ATMT method was successfully applied to L. tuber-regium. This reliable and efficient transformation method could be a powerful tool for strain genetic improvement and gene function study in L. tuber-regium.

Cardiomyogenic differentiation of human adipose-derived mesenchymal stem cells transduced with Tbx20-encoding lentiviral vectors.

Ischemic heart disease often results in myocardial infarction and is the leading cause of mortality and morbidity worldwide. Improvement in the function of infarcted myocardium is a main purpose of cardiac regenerative medicine. One possible way to reach this goal is via stem cell therapy. Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a variety of cell types but display limited cardiomyogenic differentiation potential. Members of the T-box family of transcription factors including Tbx20 play important roles in heart development and cardiomyocyte homeostasis. Therefore, in the current study, we investigated the potential of Tbx20 to enhance the cardiomyogenic differentiation of human adipose-derived MSCs (ADMSCs). Human ADMSCs were transduced with a bicistronic lentiviral vector encoding Tbx20 (murine) and the enhanced green fluorescent protein (eGFP) and analyzed 7 and 14 days post transduction. Transduction of human ADMSCs with this lentiviral vector increased the expression of the cardiomyogenic differentiation markers ACTN1, TNNI3, ACTC1, NKX2.5, TBX20 (human), and GATA4 as revealed by RT-qPCR. Consistently, immunocytological results showed elevated expression of α-actinin and cardiac troponin I in these cells in comparison to the cells transduced with control lentiviral particles coding for eGFP alone. Accordingly, forced expression of Tbx20 exerts cardiomyogenic effects on human ADMSCs by increasing the expression of cardiomyogenic differentiation markers at the RNA and protein level.

Cloning and heterologous expression of a hydrophobin gene Ltr. hyd from the tiger milk mushroom Lentinus tuber-regium in yeast-like cells of Tremella fuciformis

Background: Hydrophobins are small proteins secreted by filamentous fungi, which show a highly surface activity. Because of the signally self-assembling abilities and surface activities, hydrophobins were considered as candidates in many aspects, for example, stabilizing foams and emulsions in food products. Lentinus tuber-regium, known as tiger milk mushroom, is both an edible and medicinal sclerotium-producing mushroom. Up to now, the hydrophobins of L. tuber-regium have not been identified. Results: In this paper, a Class I hydrophobin gene, Ltr.hyd, was cloned from L. tuber-regium and expressed in the yeast-like cells of Tremella fuciformis mediated by Agrobacterium tumefaciens. The expression vector pGEH-GH was under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter. The integration of Ltr.hyd into the genome of T. fuciformis was confirmed by PCR, Southern blot, fluorescence observation and quantitative real-time PCR (qRT-PCR). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that recombinant hydrophobin rLtr.HYD with an expected molecular mass of 13 kDa was extracted. The yield of rLtr.HYD was 0.66 mg/g dry weight. The emulsifying activity of rLtr.HYD was better than the typical food emulsifiers sodium caseinate and Tween 20. Conclusions: We evaluated the emulsifying property of hydrophobin Ltr.HYD, which can be potentially used as a food emulsifier.

IL-33 Attenuates Sepsis by Inhibiting IL-17 Receptor Signaling through Upregulation of SOCS3.

BACKGROUND/AIMS: Sepsis is a systemic inflammatory response during infection. There are limited therapeutic options for sepsis patients. Interleukin (IL)-33 has been reported recently with a beneficial effect in mouse sepsis. METHODS: In this study, we initiated a clinical study to measure serum levels of pro-inflammatory cytokines including IL-33 in sepsis patients. Next, we employed cecal ligation and puncture (CLP) to study the role of IL-33 during sepsis. To further dissect the molecular mechanism, we used in vivo knockout models and in vitro knockdown murine embryonic fibroblasts (MEFs) to investigate the cross-talk between IL-33 and IL-17 signaling, and to identify the potential downstream mediators. RESULTS: IL-33 and IL-17 were upregulated in both clinical and experimental sepsis. In CLP, IL-33 (-/-) mice showed higher mortality rate, and IL-33 treatment improved the survival rate. Elevated proinflammatory cytokines in sepsis were related to IL-17 from γδT cells. IL-33 treatment suppressed production of these cytokines by targeting IL-17 signaling both in vivo and in vitro. Finally, IL-33 was shown to inhibit the IL-17 pathway via activating suppressor of cytokine signaling (SOCS)-3. CONCLUSION: Collectively, the results suggest that IL-33 plays a negative regulatory role in sepsis progression by inhibiting IL-17 pathway through activating SOCS3. This finding would inspire a new therapeutic strategy for treating sepsis.

Lentinoid and Polyporoid Fungi, Two Generic Conglomerates Containing Important Medicinal Mushrooms in Molecular Perspective.

Polyporoid and lentinoid fungi contain the important producers of substances having immunomodulatory, antitumoral, antiviral, and antihyperlipidemic effects. The discovery of several phylogenetic lines within the lentinoid-polyporoid continuum will help with target metabolomic analysis of species still not studied in pharmacological respects. The purpose of the present work was to increase a resolution in the lentinoid-polyporoid phylogenetic zone by means of selection of both the main representatives of Lentinus-related genera and poorly known/intermediate taxa such as Lentinus suavissimus, Neofavolus spp., and the resupinate part of Polyporus (genera Perenniporia and Pachykytospora) in the context of the basic structure of the Polyporales tree. The molecular phylogeny of highlighting all the polyporoid and lentinoid nodes was reconstructed using nLSU ITS rDNA and TEF datasets. The data obtained from ITS, TEF, and LSU coincide in support of core Polyporaceae of 10 clades corresponded to the generic level and 7 of these (Cerioporus, Cladomeris, Favolus, Lentinus, Neofavolus, Picipes, and Polyporus s.str.) contain generic units characterized by polyporoid or lentinoid morphotypes. The other 2 clades containing lentinoid taxa are outside the core Polyporaceae, namely Panus (Meruliaceae, Polyporales) and Neolentinus (Gloeophyllaceae, Gloeophyllales). A new genus, Picipes, is described and 25 new combinations are proposed.

The molecular basis of polysaccharide cleavage by lytic polysaccharide monooxygenases.

Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes that oxidatively break down recalcitrant polysaccharides such as cellulose and chitin. Since their discovery, LPMOs have become integral factors in the industrial utilization of biomass, especially in the sustainable generation of cellulosic bioethanol. We report here a structural determination of an LPMO-oligosaccharide complex, yielding detailed insights into the mechanism of action of these enzymes. Using a combination of structure and electron paramagnetic resonance spectroscopy, we reveal the means by which LPMOs interact with saccharide substrates. We further uncover electronic and structural features of the enzyme active site, showing how LPMOs orchestrate the reaction of oxygen with polysaccharide chains.

Phylogenetic relationships and morphological evolution in Lentinus, Polyporellus and Neofavolus, emphasizing southeastern Asian taxa.

The genus Lentinus (Polyporaceae, Basidiomycota) is widely documented from tropical and temperate forests and is taxonomically controversial. Here we studied the relationships between Lentinus subg. Lentinus sensu Pegler (i.e. sections Lentinus, Tigrini, Dicholamellatae, Rigidi, Lentodiellum and Pleuroti and polypores that share similar morphological characters). We generated sequences of internal transcribed spacers (ITS) and partial 28S regions of nuc rDNA and genes encoding the largest subunit of RNA polymerase II (RPB1), focusing on Lentinus subg. Lentinus sensu Pegler and the Neofavolus group, combined these data with sequences from GenBank (including RPB2 gene sequences) and performed phylogenetic analyses with maximum likelihood and Bayesian methods. We also evaluated the transition in hymenophore morphology between Lentinus, Neofavolus and related polypores with ancestral state reconstruction. Single-gene phylogenies and phylogenies combining ITS and 28S with RPB1 and RPB2 genes all support existence of a Lentinus/Polyporellus clade and a separate Neofavolus clade. Polyporellus (represented by P. arcularius, P. ciliatus, P. brumalis) forms a clade with species representing Lentinus subg. Lentinus sensu Pegler (1983), excluding L. suavissimus. Lentinus tigrinus appears as the sister group of Polyporellus in the four-gene phylogeny, but this placement was weakly supported. All three multigene analyses and the single-gene analysis using ITS strongly supported Polyporus tricholoma as the sister group of the Lentinus/Polyporellus clade; only the 28S rRNA phylogeny failed to support this placement. Under parsimony the ancestral hymenophoral configuration for the Lentinus/Polyporellus clade is estimated to be circular pores, with independent transitions to angular pores and lamellae. The ancestral state for the Neofavolus clade is estimated to be angular pores, with a single transition to lamellae in L. suavissimus. We propose that Lentinus suavissimus (section Pleuroti) should be reclassified as Neofavolus suavissimus comb. nov.

Production and molecular characterization of somatic hybrids between Pleurotus florida and Lentinula edodes.

Nine inter-generic somatic hybrids named as pfle were produced through PEG-mediated protoplast fusion between Pleurotus florida and Lentinula edodes using double selection method. Hybridity of the newly developed strains was established on the basis of colony morphology, mycelial growth, hyphal traits, fruit-body productivity and inter single sequence repeat (ISSR) marker profiling. Hybrid population was assessed with different phenotypic variables by one-way analysis of variance. Principal component matrices were analyzed for the six phenotypic variables in scatter plot showing maximum positive correlation between each variable for all strains examined. Six ISSR primers generated 66 reproducible fragments with 98.48 % polymorphism. The dendrogram thus created based on unweighted pair-group method with mathematic averages method of clustering and Euclidean distance which exhibited three major groups between the parents and pfle hybrids. Though P. florida parent remained in one group but it showed different degrees of genetic distance with all the hybrid lines belonging to the other two groups while L. edodes was most distantly related to all the hybrid lines. L. edodes specific sequence-rich ISSR amplicon was recorded in all the hybrid lines and in L. edodes but not in P. florida. All the fruit body generating pfle hybrid lines could produce basidiocarp on paddy straw in sub-tropical climate and showed phenotypic resemblance to the P. florida parent.

Structural characterization of an immunoenhancing heteroglycan of a hybrid mushroom (pfls1h) of Pleurotus florida and Lentinus squarrosulus (Mont.) Singer.

An immunostimulating water-soluble heteroglycan (PS-II) was isolated from an aqueous extract of the fruit bodies of a hybrid mushroom, pfls1h produced by intergeneric protoplast fusion between Pleurotus florida and Lentinus squarrosulus (Mont.) Singer. Structural characterization of PS-II was carried out using sugar analysis, methylation experiment, periodate oxidation and 1D/2D NMR studies. Sugar analysis indicated the presence of glucose, mannose and galactose in a molar ratio of 1:1:2. Methylation analysis revealed that PS-II was composed of (1→6)- and (1→2,4,6)-α-D-galactopyranosyl, terminal ß-D-mannopyranosyl and terminal ß-D-glucopyranosyl residues in a relative proportion of approximately 1:1:1:1. On the basis of chemical analysis and NMR studies, the structure of the repeating unit of the heteroglycan was established to consist of a backbone chain of two (1→6)-α-D-galactopyranosyl residues, one of which is branched at O-2 with terminal ß-D-Manp and at O-4 with terminal ß-D-Glcp. This heteroglycan (PS-II) showed in vitro splenocyte, thymocyte and macrophage activations.

Lentinus (Panus) tigrinus augmentation of a historically contaminated soil: matrix decontamination and structure and function of the resident bacterial community.

The ability of Lentinus tigrinus to grow and to degrade persistent aromatic hydrocarbons in aged contaminated soil was assessed in this study. L. tigrinus extensively colonized the soil; its degradation activity after 60 d incubation at 28°C, however, was mostly limited to dichloroaniline isomers, polychlorinated benzenes and diphenyl ether while the fungus was unable to deplete 9,10-anthracenedione and 7-H-benz[DE]anthracene-7-one which were the major soil contaminants. Although clean-up levels were limited, both density of cultivable heterotrophic bacteria and richness of the resident bacterial community in L. tigrinus microcosms (LtM) increased over time to a significantly larger extent than the respective amended incubation controls (1.9×10(9) CFU g(-1) vs. 1.0×10(9) CFU g(-1) and 37 vs. 16, respectively). Naphthalene- and catechol 2,3-dioxygenase gene copy numbers, however, decreased over time at a higher rate in LtM than in incubation controls likely due to a higher stimulation on heterotrophs than xenobiotics-degrading community members.

Biosorption of Reactive Red-120 dye from aqueous solution by native and modified fungus biomass preparations of Lentinus sajor-caju.

The capacities and mechanisms of native and treated white-rot fungus "Lentinus sajur-caju" biomass preparations in removing of textile dye (i.e. Reactive Red-120) from aqueous solution was investigated with different parameters, such as adsorbent dosage, pH, temperature and ionic strength. In the batch system, the maximum dye uptake on all the tested fungal biomass preparations was observed at pH 3.0, and the dye uptake capacities of the biosorbents (at 800 mg/l dye concentration) were found to be 117.8, 182.9, 138.6 and 57.2mg/g for native and heat-, acid- and base-treated dry fungal preparations, respectively. The uptake capacities order of the fungal preparations for the dye were found as heat-treated>acid-treated>native>base-treated. The Langmuir, Freundlih and Temkin adsorption models were used for the mathematical description of the biosorption equilibrium. The Freundlich and Temkin models were able to describe the biosorption equilibrium of Reactive Red-120 on the fungal biomass preparations. The dye biosorption on the fungal biomass preparations followed second-order kinetic model and equation.

Optimal conditions for the fruit body production of natural occurring strains of Lentinus tigrinus.

Lentinus tigrinus is a species with a fleshy pileus, strong odor and agreeable taste. In order to determine the optimal conditions for the production of this species, three substrates based on Salix sp. sawdust, wheat straw and supplements were tested in 500g dry weight bags at two different fruiting temperatures. Naturally occurring strains of this species were incubated at 30 degrees C. Primordium initiation could be observed 11-16 days after induction conditions began. This species produced highest yields with biological efficiency (BE) of 62% with supplemented sawdust at 25 degrees C. When bags were reduced to 100g dry weight, spawning run time was reduced from 28 to 30 to 10 to 14 days and BE increased more than 100%. L. tigrinus is a promising species with possibilities for commercial production.

Lentinula edodes tlg1 encodes a thaumatin-like protein that is involved in lentinan degradation and fruiting body senescence.

Lentinan is an antitumor product that is purified from fresh Lentinula edodes fruiting bodies. It is a cell wall component, comprising beta-1,3-glucan with beta-1,6-linked branches, which becomes degraded during postharvest preservation as a result of increased glucanase activity. In this study, we used N-terminal amino acid sequence to isolate tlg1, a gene encoding a thaumatin-like (TL) protein in L. edodes. The cDNA clone was approximately 1.0 kb whereas the genomic sequence was 2.1 kb, and comparison of the two indicated that tlg1 contains 12 introns. The tlg1 gene product (TLG1) was predicted to comprise 240 amino acids, with a molecular mass of 25 kD and isoelectric point value of 3.5. The putative amino acid sequence exhibits approximately 40% identity with plant TL proteins, and a fungal genome database search revealed that these TL proteins are conserved in many fungi including the basidiomycota and ascomycota. Transcription of tlg1 was not detected in vegetative mycelium or young and fresh mushrooms. However, transcription increased following harvest. Western-blot analysis demonstrated a rise in TLG1 levels following harvest and spore diffusion. TLG1 expressed in Escherichia coli and Aspergillus oryzae exhibited beta-1,3-glucanase activity and, when purified from the L. edodes fruiting body, demonstrated lentinan degrading activity. Thus, we suggest that TLG1 is involved in lentinan and cell wall degradation during senescence following harvest and spore diffusion.

Cloning and functional characterization of a Delta12 fatty acid desaturase gene from the basidiomycete Lentinula edodes.

In the basidiomycete Lentinula edodes, a famous edible mushroom (shiitake), the fatty acyl composition of total lipids has previously been shown to change during cell differentiation. In the present study, we succeeded in cloning a gene for a Delta12 fatty acid desaturase from L. edodes. The ORF of this gene (named Le-FAD2) consists of 1308 bp and codes for 435 amino acids. The deduced Le-FAD2 protein shows 40-45% identity to Delta12 fatty acid desaturases from other fungi, and the three histidine clusters typical of the catalytic domain of such enzymes are conserved. Expression of the Le-FAD2 gene in the budding yeast Saccharomyces cerevisiae indicated that its product was able to synthesize linoleic acid (C18:2). Analysis of Le-FAD2 expression in L. edodes revealed that levels of transcription were higher in fruiting body primordia and in mature fruiting bodies, the two differentiated tissues, than in mycelium, and reduction of the growth temperature from 25 to 18 degrees C had no effect on the level of the Le-FAD2 transcript. Thus, although Le-FAD2 expression is correlated with the alteration in the complement of unsaturated fatty acids (UFAs) observed during fruiting body formation, the gene does not respond to a downshift in temperature to 18 degrees C.

Isolation of genes specifically expressed in the fruit body of the edible basidiomycete Lentinula edodes.

In order to isolate the genes expressed specifically and abundantly in the mature fruit body of Lentinula edodes, the cDNAs derived from the gill of the fruit body were compared with the cDNAs from the mycelia by differential screening. Consequently, six clones were identified as fruit-body-specific genes (fbg03, 08, 13, 14, 16, and 21). The deduced amino acid sequence of fbg14 (Le.cypfb) had significant homology with the cytochrome P450 protein. The transcriptional level of fbg16, which showed 29.9% identity with the riboflavin aldehyde-forming enzyme of Agaricus bisporus, was highest among all of the fbg clones. This result indicates that the promoter region of fbg16 may become a powerful candidate for the expression signal of the vector for the gene manipulation in the mature fruit body.