Lyophyllum Decastes Research Articles

Screening of the Candidate Metabolite to Evaluate the Mycelium Physiological Maturation of Lyophyllum decastes Based on Metabolome and Transcriptome Analysis

Lyophyllum decastes is a commercially cultivated rare edible mushroom with high dietary and medicinal value. The mycelium physiological maturation was an important factor to the yield and quality of mushrooms obtained. However, it was impossible to obtain discriminative characteristics represented the maturity level of the mycelia from morphological features. In this article, we screened a candidate metabolite for evaluating the mycelium physiological maturation by metabolomic and transcriptomic analysis during mycelial vegetative growth stages of L. decastes. The results showed that mycelial vegetative growth 55 d had reached to physiological maturation according to the yield and quality of L. decastes, which the single bottle yield (307 g/bottle), the contents of flavonoids (2.94 mg/g dry weight), and 5 flavor amino acids (glutamate 177.90 μg/g, aspartate 95.74 μg/g, phenylalanine 31.68 μg/g, tyrosine 13.79 μg/g, and alanine 10.99 μg/g) were the highest. In addition, the metabolomic and transcriptomic analysis results showed that biosynthesis of secondary metabolites and amino acid had significant different during mycelial vegetative growth stages, and glutamine may be a candidate indicator to evaluate the mycelial physiological maturation. These findings contribute to improve our knowledge of mycelium physiological maturation and it will be used to increase mushroom yield and quality.

Growth Simulation of Lyophyllum decastes and Coprinus comatus and Their Influencing Factors in a Forested Catchment

Wild edible mushrooms are an important food source globally and have a crucial role in forest ecosystems. However, there is limited research on the growth characteristics and the contribution of agronomic traits to biomass, and the environmental factors affecting mushroom growth are limited. This study was conducted in the Qilian Mountains, China, and focused on investigating the growth patterns and agronomic traits of Lyophyllum decastes and Coprinus comatus. The results revealed that the growth of these mushrooms followed a logical growth curve. By calculating the model parameters, we obtained the maximum daily growth of height (PH), pileus diameter (PD), and cluster perimeter (CP) of L. decastes on the 5th, 7th, and 7th days, respectively, with values of 0.55 cm d−1, 0.54 cm d−1, and 4.54 cm d−1, respectively. However, the maximum daily growth of PH, pileus length (PL), and PD of the C. comatus appeared on the 3rd day, 2nd day, and 2nd day of the observation, respectively. This study identified near-surface relative humidity, air relative humidity, and rainfall as the primary factors influencing mushroom growth, as indicated by Pearson’s correlation analysis, redundancy analysis (RDA), and multiple linear and stepwise regression. Additionally, land surface temperature and air temperature were also identified as important factors affecting mushroom growth. By utilizing random forest and stepwise regression analysis, this study identified PH and stipe diameter (SD) as the most crucial agronomic traits affecting mushroom biomass. Overall, this study offers insights for industrial mushroom cultivation and basic fungal research.

Structural characterization and immune activity evaluation of a polysaccharide from Lyophyllum Decastes

An innovative acidic hydrolysate fingerprinting workflow was proposed for the characterization of Lyophyllum Decastes polysaccharide (LDP) by ultra performance liquid chromatography-mass spectrometry (UPLC-MS). The crude polysaccharides were firstly separated and purified by using DE-52 column and the BRT GPC purification system, respectively. The molecular weight and monosaccharide content of homogeneous polysaccharides were ascertained by utilizing HPGPC and ion chromatography separately. Secondly, the linkage of LDP was identified by methylation analysis and 1D/2D NMR spectra. The UPLC-MS/MS was used to scan and identify the acidic hydrolysate products of LDP using the PGC column. The oligosaccharides were collected by chromatography and identified by mass spectrometry. Thirdly, the expression of IL-1β, IL-6, iNOS, TNF-α and IFNAR-I was measured in order to assess the immunological activity of LDP. Besides, the targeted receptors identification of polysaccharides was performed by screening the expression of TLRs family protein. The results showed that oligosaccharide fragments with different molecular weights can be obtained by partial hydrolysis, which further verified that the structures of LDP polysaccharides was a 1–6-linked β-glucan. Moreover, the LDP polysaccharide can up-regulate the content of IL-1β, IL-6, iNOS, TNF-α and IFNAR-I and plays an important immunoregulation role through TLRs family.

Insights into the evolution and mechanisms of response to heat stress by whole genome sequencing and comparative proteomics analysis of the domesticated edible mushroom Lepista sordida

ABSTRACT Lepista sordida is a valuable edible mushroom rich in natural bioactive compounds. In the present study, a high-quality whole-genome of a domesticated strain of L. sordida was sequenced, revealing a 40.67 Mb genome in 13 contigs. Phylogenetic analysis revealed that L. sordida is evolutionarily closely related to edible mushroom Lyophyllum decastes and Hypsizygus marmoreus. Heat stress has a significant effect on the yield and quality of mushrooms, but the molecular basis for this is poorly understood in L. sordida. A label-free comparative proteomic analysis was performed under different heat stress conditions. The growth of L. sordida mycelia was inhibited, and nuclear apoptosis occurred under heat stress. Ca2+ and MAPK signaling pathways were found to be involved in heat stress signal transduction. It is hypothesized that the expression of various heat shock proteins plays a crucial role in the response to heat stress. In addition, the components of the ubiquitin-proteasome system and the thioredoxin system were upregulated, preventing the accumulation of misfolded proteins and possibly supporting the response to heat stress. In summary, these results provide a fundamental insight into the evolution and heat stress-responsive mechanisms in L. sordida and may facilitate the breeding of heat-tolerant strains for artificial cultivation.

The development and nutritional quality of Lyophyllum decastes affected by monochromatic or mixed light provided by light-emitting diode.

Edible fungi has certain photo-sensitivity during the mushroom emergence stage, but there has been few relevant studies on the responses of Lyophyllum decastes to different light quality. L. decastes were planted in growth chambers with different light qualities that were, respectively, white light (CK), monochromatic red light (R), monochromatic blue light (B), mixed red and blue light (RB), and the mixture of far-red and blue light (FrB). The photo-sensitivity of L. decastes was investigated by analyzing the growth characteristics, nutritional quality, extracellular enzymes as well as the light photoreceptor genes in mushroom exposed to different light treatments. The results showed that R led to mycelium degeneration, fungal skin inactivation and failure of primordial formation in L. decastes. The stipe length, stipe diameter, pileus diameter and the weight of fruiting bodies exposed to RB significantly increased by 8.0, 28.7, 18.3, and 58.2% respectively, compared to the control (p < 0.05). B significantly decreased the stipe length and the weight of fruiting body, with a decrease of 8.5 and 20.2% respectively, compared to the control (p < 0.05). Increased color indicators and deepened simulated color were detected in L. decastes pileus treated with B and FrB in relative to the control. Meanwhile, the expression levels of blue photoreceptor genes such as WC-1, WC-2 and Cry-DASH were significantly up-regulated in mushroom exposed to B and FrB (p < 0.05). Additionally, the contents of crude protein and crude polysaccharide in pileus treated with RB were, respectively, increased by 26.5 and 9.4% compared to the control, while those in stipes increased by 5.3 and 58.8%, respectively. Meanwhile, the activities of extracellular enzyme such as cellulase, hemicellulase, laccase, manganese peroxidase, lignin peroxidase and amylase were significant up-regulated in mushroom subjected to RB (p < 0.05), which may promote the degradation of the culture materials. On the whole, the largest volume and weight as well as the highest contents of nutrients were all detected in L. decastes treated with RB. The study provided a theoretical basis for the regulation of light environment in the industrial production of high quality L. decastes.

Identification and fungicides sensitivity evaluation of the causal agent of cobweb disease on Lyophyllum decastes in China

BackgroundCobweb disease is a fungal disease that commonly affects the cultivation and production of edible mushrooms, leading to serious yield and economic losses. It is considered a major fungal disease in the realm of edible mushrooms. The symptoms of cobweb disease were found during the cultivation of Lyophyllum decastes. This study aimed to identify the causative pathogen of cobweb disease and evaluate effective fungicides, providing valuable insights for field control and management of L. decastes cobweb disease.ResultsThe causal agent of cobweb disease was isolated from samples infected and identified as Cladobotryum mycophilum based on morphological and cultural characteristics, as well as multi-locus phylogeny analysis (ITS, RPB1, RPB2, and TEF1-α). Pathogenicity tests further confirmed C. mycophilum as the responsible pathogen for this condition. Among the selected fungicides, Prochloraz-manganese chloride complex, Trifloxystrobin, tebuconazole, and Difenoconazole exhibited significant inhibitory effects on the pathogen’s mycelium, with EC50 values of 0.076 µg/mL, 0.173 µg/mL, and 0.364 µg/mL, respectively. These fungicides can serve as references for future field control of cobweb disease in L. decastes.ConclusionThis study is the first report of C. mycophilum as the causing agent of cobweb disease in L. decastes in China. Notably, Prochloraz-manganese chloride complex demonstrated the strongest inhibitory efficacy against C. mycophilum.

Comparative transcriptome analysis on candidate genes associated with fruiting body growth and development in Lyophyllum decastes.

Lyophyllum decastes is a mushroom that is highly regarded for its culinary and medicinal properties. Its delectable taste and texture make it a popular choice for consumption. To gain a deeper understanding of the molecular mechanisms involved in the development of the fruiting body of L. decastes, we used RNA sequencing to conduct a comparative transcriptome analysis. The analysis encompassed various developmental stages, including the vegetative mycelium, primordial initiation, young fruiting body, medium-size fruiting body, and mature fruiting body stages. A range of 40.1 to 60.6 million clean reads were obtained, and de novo assembly generated 15,451 unigenes with an average length of 1,462.68 bp. Functional annotation of transcriptomes matched 76.84% of the unigenes to known proteins available in at least one database. The gene expression analysis revealed a significant number of differentially expressed genes (DEGs) between each stage. These genes were annotated and subjected to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Highly differentially expressed unigenes were also identified, including those that encode extracellular enzymes, transcription factors, and signaling pathways. The accuracy of the RNA-Seq and DEG analyses was validated using quantitative PCR. Enzyme activity analysis experiments demonstrated that the extracellular enzymes exhibited significant differences across different developmental stages. This study provides valuable insights into the molecular mechanisms that underlie the development of the fruiting body in L. decastes.

First report of Fusarium solani causing root rot in mushroom (Lyophyllum decastes) in China

First report of Fusarium solani causing root rot in mushroom (Lyophyllum decastes) in China

Structural characterization of an antioxidant polysaccharide isolated from the fruiting bodies of Lyophyllum decastes

It is well known that mushroom-derived compounds have numerous medicinal/bioactivities, such as immunomodulatory, antidiabetic, antiviral, antimicrobial, hepatoprotective and antitumor activities. In the current study, we investigate the purification, structural characteristics, and anti-oxidation activity of Lyophyllum decastes polysaccharide. A new polysaccharide, LDSP60-A, was isolated from the fruiting bodies of L. decastes using hot water extraction, ethanol precipitation and chromatography. Chemical structural analysis showed that this polysaccharide is mainly composed of D-glucose and D-galactose (in the ratio of 1.00:0.64, with a molecular weight of 6.18 × 105 Da). Methylation analysis, one-dimensional 1H- and 13C- nuclear magnetic resonance (NMR) and two-dimensional NMR spectroscopy revealed that LDSP60-A has a β-1,6-D-glucopyranose (Glcp) backbone and with a minor terminal-D-Glcp and 1,6-D-galactopyranose (Galp). The antioxidant activity of LDSP60-A, evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) free radical scavenging, showed that it had a high antioxidant activity with the activity for scavenging DPPH and ABTS+ free radicals of up to 78.6% and 97.33% at concentrations of 1.2 and 0.8 mg/mL, respectively. These results provide useful information for developing L. decastes polysaccharide-related foods and promote application of the L. decastes in the pharmaceutical and functional food industries.

Complete genome sequences and comparative secretomic analysis for the industrially cultivated edible mushroom Lyophyllum decastes reveals insights on evolution and lignocellulose degradation potential.

Lyophyllum decastes, also known as Luronggu in China, is a culinary edible and medicinal mushroom that was widely cultivated in China in recent years. In the present study, the complete high-quality genome of two mating compatible L. decastes strain was sequenced. The L. decastes LRG-d1-1 genome consists of 47.7 Mb in 15 contigs with a contig N90 of 2.08 Mb and 14,499 predicted gene models. Phylogenetic analysis revealed that L. decastes exhibits a close evolutionary relationship to the Termitomyces and Hypsizygus genus and was diverged from H. marmoreus ~ 45.53 Mya ago. Mating A loci of L. decastes compose of five and four HD genes in two monokaryotic strains, respectively. Mating B loci compose of five STE genes in both two monokaryotic strains. To accelerate the cross-breeding process, we designed four pairs of specific primers and successfully detected both mating types in L. decastes. As a wood-rotting mushroom, a total of 541 genes accounting for 577 CAZymes were identified in the genome of L. decastes. Proteomic analysis revealed that 1,071 proteins including 182 CAZymes and 258 secreted enzymes were identified from four groups (PDB, PDB + bran, PDB + cotton hull, and PDB + sawdust). Two laccases and a quinone reductase were strongly overproduced in lignin-rich cultures, and the laccases were among the top-3 secreted proteins, suggesting an important role in the synergistic decomposition of lignin. These results revealed the robustness of the lignocellulose degradation capacity of L. decastes. This is the first study to provide insights into the evolution and lignocellulose degradation of L. decastes.

Effects of polysaccharides from Lyophyllum decastes (Fr.) Singer on gut microbiota via in vitro-simulated digestion and fermentation.

Lyophyllum decastes (Fr.) Singer polysaccharides (LDSPs) have been verified to possess strong biological properties. However, the effects of LDSPs on intestinal microbes and their metabolites have rarely been addressed. The in vitro-simulated saliva-gastrointestinal digestion and human fecal fermentation were used to evaluate the effects of LDSPs on non-digestibility and intestinal microflora regulation in the present study. The results showed a slight increase in the content of the reducing end of the polysaccharide chain and no obvious change in the molecular weight during in vitro digestion. After 24 h in vitro fermentation, LDSPs were degraded and utilized by human gut microbiota, and LDSPs could be transformed into short-chain fatty acids leading to significant (p < 0.05) decrease in the pH of the fermentation solution. The digestion did not remarkably affect the overall structure of LDSPs and 16S rRNA analysis revealed distinct shifts in the gut microbial composition and community diversity of the LDSPs-treated cultures, compared with the control group. Notably, the LDSPs group directed a targeted promotion of the abundance of butyrogenic bacteria, including Blautia, Roseburia, and Bacteroides, and an increase in the n-butyrate level. These findings suggest that LDSPs might be a potential prebiotic to provide a health benefit.

Structural characterization of a polysaccharide from Lyophyllum decastes with MAPK-mediated immune regulation ability in mice

Lyophyllum decastes is a common macrofungi for both medicinal and economic value, and its polysaccharide has excellent development potential as a new immune regulator. In the present study, the bioactive component polysaccharide of L decastes was extracted, and its chain structure was characterized in detail by Fourier transform infrared (FT-IR) spectroscopy, high-performance gel-permeation chromatography (HP-GPC), and gas chromatography–mass spectrometry (GC–MS). LDP-W had a molecular weight of 2.12 × 104 Da, highly branched β type pyranose. At the same time, it exhibited potential immunomodulatory activity, which can modulate the numbers of CD3+, CD4+, CD8+ and CD19+ cells in the spleen; optimize the CD4+/CD8+ ratio; promoted T and B lymphocyte proliferation and it can elevate the levels of IL-2, IL-6, IFN-γ and TNF-α in immunosuppressed mice by influencing the phosphorylation of MAPK signaling-related proteins. These studies fill the gap in the immune regulation mechanism of L decastes polysaccharide, providing a theoretical basis for the potential application of LDP-W as immunomodulatory drugs or functional foods.

Toxicity Test of Some Selected Wild Mushrooms of Nepal

People have been using wild mushrooms in their diet and also as sources of income, but most of them do not have the proper knowledge to distinguish edible mushrooms from poisonous ones. The main objective of this research is to determine and document toxicity of some selected wild mushrooms of Nepal. Samples were collected based on their use practices by the local communities, representing different ecological belts. The tests were carried out following the protocol described in ‘Test Guideline no. 425: Acute Oral Toxicity: Up-and-Down Procedure’. Mice (Mus musculus) were administered with aqueous solution of each sample in a single dose by gavage using a stomach tube on the basis of their body weight and were observed for the signs of toxicity. The tested samples of Boletellus emodensis, Caloboletus calopus, Daedalea quercina, Lactifluus volemus, Lyophyllum decastes, Macrolepiota albuminosa, Phellodon niger, Phylloporus bellus, Russula delica, R. emetica, R. senecis, Strobilomyces strobilaceus, Termitomyces eurrhizus, T. le-testui, T. mammiformis, T. robustus, T. striatus f. brunneus, T. straitus f. pileatus, Trametes vernicipes and Trichaptum biforme revealed LD50 value &gt; 2000 mg.kg-1 body weight indicating that they may be harmful if swallowed . However, in case of Hapalopilus rutilans, LD50 value of 1212 mg.kg-1 body weight was observed confirming that it is harmful when swallowed.

Effects of ultrasonic treatment on the surface bacteria of Lyophyllum decastes during storage

This study explores the relationship between the storage quality and bacterial microflora in the mushroom Lyophyllum decastes. The surface bacteria of L. decastes were separated by combining the traditional culture plate separation and 16S rRNA sequencing method, to study the effects of ultrasonic (US) treatment on the surface bacteria of L. decastes during storage. The results demonstrated that Pantoea agglomerans and Pseudomonas fluorescens were among the 15 culturable bacteria isolated with traditional plate method during storage, belonging to 2 phyla and 7 genera. US treatment could inhibit the growth and significantly increase cell membrane permeability, and contents extravasation in P. agglomerans, though its inhibitory effect on P. fluorescens was less. The 16S rRNA sequencing revealed, bacteria from 9 phyla and 35 genera were isolated, and P. fluorescens was the dominant species throughout the storage time. These results indicated that the composition of mushroom surface microflora of Control (CK) and US groups are similar, and the bacterial microflora networks analysis also showed a positive correlation. The KEGG annotation for the functional classification of the bacteria showed that a total of 328 pathways were acquired at the KEGG l3 level, and the relative abundance of membrane transport, amino acid metabolism, carbohydrate metabolism, and energy metabolism pathway was high. Moreover, the relative abundance of the surface bacteria of L. decastes also decreased. Hence, the US treatment had a better bacteriostatic effect, maintained the whiteness index and firmness, and improved the sensory quality of L. decastes during storage.

Effects of Drying Methods on the Physicochemical Aspects and Volatile Compounds of Lyophyllum decastes.

In this study, fresh Lyophyllum decastes was dried using hot air drying (HAD), hot air combined with vacuum drying (HAVD), and vacuum freeze drying (VFD). Additionally, the quality and volatile compounds were analyzed. VFD achieved the best color retention, the highest rehydration capacity, and the slightest damaged tissue structure; however, it recorded the longest drying time and the highest energy consumption. HAD was the most energy-efficient of the three methods. Furthermore, the products with more hardness and elasticity were obtained by HAD and HAVD—this finding was convenient for transportation. In addition, GC-IMS demonstrated that the flavor components had significantly changed after drying. A total of 57 volatile flavor compounds was identified, and the aldehyde, alcohol, and ketone compounds were the primary ingredient of the L. decastes flavor component, whereby the relative content of the HAD sample was apparently higher than HAVD and VFD. Taken together, VFD was better at preserving the color and shape of fresh L. decastes, but HAD was more appropriate for drying L. decastes because of the lower energy consumption, and was more economical. Meanwhile, HAD could be used to produce a more intense aroma.

Ultrasonic treatment decreases Lyophyllum decastes fruiting body browning and affects energy metabolism

Lyophyllum decastes is a common mushroom that is prone to browning during prolonged storage. In this study, the effects of ultrasonic treatment on metabolic gene expression, enzyme activity, and metabolic compounds related to L. decastes browning were investigated. Treatment of the fruiting body at 35 kHz and 300 W for 10 min reduced the browning index of L. decastes by 21.0 % and increased the L* value by 11.1 %. Ultrasonic treatment of the fruiting body resulted in higher levels of total phenols, flavonoids, and 9 kinds of amino acid with catalase (CAT) and peroxidase (POD) activities maintained at high levels. Higher cytochrome c oxidase (CCO), succinate dehydrogenase (SDH), phosphofructokinase (PFK), and pyruvate kinase (PK) activities may be ascribed to increased antioxidant capacity. Moreover, ultrasonication retained higher adenosine triphosphate (ATP) concentrations with an increased energy charge, while there were lower levels of adenosine diphosphate (ADP) and reduced and oxidized nicotinamide adenine dinucleotide (NADH and NAD+), respectively. Meanwhile, lower lignin contents were observed, along with retarded polyphenol oxidase (PPO) and lipoxygenase (LOX) activities. Lower PPO activity reduced the fruiting body enzymatic browning rate through decreased expression of LdPpo1, LdPpo2, and LdPpo3 during storage at 4 °C for 16 days. This activity may be used to determine the effectiveness of ultrasonication.

Polysaccharides from Lyophyllum decastes reduce obesity by altering gut microbiota and increasing energy expenditure

Polysaccharides are known to confer protection against obesity via modulation of gut microbiota. To expand our knowledge of mushroom-derived prebiotics, we investigated the structural characteristics and anti-obesity effects of Lyophyllum decastes polysaccharides. Two heteroglycans were purified and characterized. The isolated polysaccharides effectively reduced obesity and the related disorders in the diet-induced obese (DIO) mice. An altered gut microbiota with enrichments of Bacteroides intestinalis and Lactobacillus johnsonii and an increase of secondary bile acids were detected in the polysaccharide-treated mice. Supplementation of B. intestinalis and L. johnsonii prevented the obesity and hyperlipidemia in DIO mice, demonstrating their causal linkage to the efficacy of polysaccharides. An enhancement of energy expenditure in the brown adipose tissues due to up-regulation of the secondary bile acids-activated TGR5 pathway was deduced to be one of the mechanisms underlying the effect of polysaccharides. These results confirmed Lyophyllum decastes-derived polysaccharides as new prebiotics for preventing and treating obesity.

Structure identification and biological activities of a new polysaccharide isolated from Lyophyllum decastes (Fr.) Sing

Background: Polysaccharide biology, whose core is the structure, function, and edible value of polysaccharides, is regarded as the last great scientific frontier outside the field of protein and nucleic acid research. Materials and Methods: In this study, highperformance gelpermeation chromatography, high-performance liquid chromatography, gas chromatography–mass spectrometry, and nuclear magnetic resonance analysis were performed to identify the structure of a new polysaccharide isolated from Lyophyllum decastes (Fr.) Sing (LDS-1). The anticancer and immunomodulatory ability of the polysaccharides (LDS-1) was also investigated. Results: The results showed that the average molecular weight of LDS-1 was 8681 Da, and the ratio between glucose and galactose was 2:1. Structural analysis revealed four (1 →4)-α-D-Glcp moieties with branches at 6-O position, and the branches consisted of two (1 →6)-β-D–Galp moieties. Our results showed that LDS-1 exhibits immunological activity. At a concentration ranging from 2.5 to 25 μg/mL, LDS-1 could distinctly promote the growth of T lymphocyte, B lymphocyte, and RAW264.7 cells; increase the secretion of IgA, IgD, IgE, IgG, IgM, tumor necrosis factor (TNF)-α, TNF-β, and interleukin-2, and enhance the phagocytotic activity of RAW264.7 cells to phagocytize fluorescent microspheres, when compared with the blank control group (P < 0.01). Furthermore, under in vitro conditions, LDS-1 (2.5-20 μg/mL) exhibited significant antineoplastic activity (P < 0.01) against colon cancer cells (CT26.WT) and S180 cells when compared with the blank control group. However, the inhibition effect was different. The research for antineoplastic activity of LDS-1 in vivo indicated that the tumor inhibition rate was 54.32%. Conclusion: In conclusion, the polysaccharides of LDS-1 exhibited good biological activities, which shows that it can be used as an immunomodulator and an antitumor agent.

Suppression of Alternaria brassicicola infection by volatile compounds from spent mushroom substrates

Most commercially circulating mushrooms are produced via cultivation using artificially produced mushroom substrates. However, after mushroom harvesting, the disposal of spent mushroom substrates (SMSs) is a serious problem for the mushroom industry owing to the need for a disposal site and the cost involved. Thus, in view of the possibility of recycling SMSs as a soil modifier, we examined the effect of soil mixed with SMSs on the infection of Arabidopsis leaves by Alternaria brassicicola, the causal agent of cabbage leaf spot. The mixing of SMSs used for Hypsizygus marmoreus, Pholiota microspora, Lyophyllum decastes, and Auricularia polytricha into culture soil suppressed the lesion formation caused by A. brassicicola. The defense responses of Arabidopsis were not induced by the culturing of these seedlings in soils containing SMSs. Suppressed lesion formation was observed after the seedlings were treated with volatiles emitted from SMSs that were incubated with soil for 7 days and used for H.marmoreus, P. microspora, L. decastes, A. polytricha, Lentinula edodes, and Cyclocybe cylindracea. The volatiles from the SMSs reduced the elongation of A. brassicicola hyphae. GC-MS analyses of extracts from the SMS containing soils led to the detection of various volatile compounds; among these, skatole, 2,4-di-tert-butylphenol, γ-dodecalactone, butyric acid, guaiacol, 6-amyl-2-pyrone, and 1-octen-3-ol were examined for inhibitory activity on A. brassicicola and found to suppress hyphae elongation. These findings indicate that the antifungal volatile compounds emitted by the SMSs suppress A. brassicicola infection.

Endophytic bacteria promote the quality of Lyophyllum decastes by improving non-volatile taste components of mycelia

Endophytic bacteria are always related to the host different traits, including the secondary metabolites production. However, the effect and mechanism of endophytic bacteria in the mushrooms fruit body on mycelia are still not clear. In this study, we investigated the effect of endophytic bacterial metabolites on the quality of Lyophyllum decastes mycelia. Soluble sugars, starch, protein, free amino acids, 5′-Nucleotides, EUC, and organic acids contents of mycelia were analyzed. We found that endophytic bacterial metabolites significantly increased the contents of soluble sugars, starch, protein, free amino acids, organic acids, and EUC. The present study thus suggests that endophytic bacteria could promote the quality of Lyophyllum decastes by improving non-volatile taste components of mycelia.