Association between macronutrients intake and liver dysfunction among tuberculosis patients in rural China.

BACKGROUND AND OBJECTIVES: Macronutrients play a vital role in liver dysfunction and affect tuberculosis treatment and prognosis. However, macronutrients intake was inadequate for most tuberculosis patients. This study aimed to clarify the associations between macronutrients intake or energy percentages and liver dys-function in tuberculosis patients. METHODS AND STUDY DESIGN: In this cross-sectional study, 2581 active tu-berculosis patients aged ≥18 years were included from local tuberculosis clinics in Linyi, China. Macronutrients intake and energy percentages were assessed by 24-hour dietary recalls. The concentration of alanine transferase (ALT) or aspartate transaminase (AST) greater than 40 U/L was defined as liver dysfunction. A restricted cubic spline (RCS) was applied to determine the dose-response relationships. RESULTS: Liver dysfunction was assessed for 14.6% (377 patients) of tuberculosis patients. Higher protein (Q2-Q4 in model 1 and 2) or fat intake and fat-to-energy percentages and lower carbohydrate-to-energy percentages (Q4 in model 1) were associated with a decreased incidence of liver dysfunction (p-trend < 0.05). Among those who were male, normal BMI, or consumed energy <1636 kcal/d, inverse associations between protein or fat intake and the risks of liver dysfunction in models were suggested (p-trend < 0.05). Moreover, J-shaped curves in RCS were evident in liver dysfunction tuberculosis patients with protein or fat intake (p-nonlinearity < 0.05). Conclu-sions: Significant linear associations between macronutrients intake or energy percentages and liver dysfunction prevalence were found only in male, normal BMI, or less energy intake patients. The shapes of liver dysfunction-morbidity differed significantly by macronutrients intake or energy percentage.

Transcriptomic Analysis of Three Differentially Senescing Maize (Zea mays L.) Inbred Lines upon Heat Stress.

Maize, one of the world's major food crops, is facing the challenge of rising temperature. Leaf senescence is the most significant phenotypic change of maize under heat stress at the seedling stage, but the underlying molecular mechanism is still unknown. Here, we screened for three inbred lines (PH4CV, B73, and SH19B) that showed differentially senescing phenotypes under heat stress. Among them, PH4CV showed no obviously senescing phenotype under heat stress, while SH19B demonstrated a severely senescing phenotype, with B73 being between the two extremes. Subsequently, transcriptome sequencing showed that differentially expressed genes (DEGs) were generally enriched in response to heat stress, reactive oxygen species (ROS), and photosynthesis in the three inbred lines under heat treatment. Notably, ATP synthesis and oxidative phosphorylation pathway genes were only significantly enriched in SH19B. Then, the expression differences of oxidative phosphorylation pathways, antioxidant enzymes, and senescence-related genes in response to heat stress were analyzed in the three inbred lines. In addition, we demonstrated that silencing ZmbHLH51 by virus-induced gene silencing (VIGS) inhibits the heat-stress-induced senescence of maize leaves. This study helps to further elucidate the molecular mechanisms of heat-stress-induced leaf senescence at the seedling stage of maize.

Effects of Different Nitrogen Levels on Lignocellulolytic Enzyme Production and Gene Expression under Straw-State Cultivation in Stropharia rugosoannulata.

Stropharia rugosoannulata has been used in environmental engineering to degrade straw in China. The nitrogen and carbon metabolisms are the most important factors affecting mushroom growth, and the aim of this study was to understand the effects of different nitrogen levels on carbon metabolism in S. rugosoannulata using transcriptome analysis. The mycelia were highly branched and elongated rapidly in A3 (1.37% nitrogen). GO and KEGG enrichment analyses revealed that the differentially expressed genes (DEGs) were mainly involved in starch and sucrose metabolism; nitrogen metabolism; glycine, serine and threonine metabolism; the MAPK signaling pathway; hydrolase activity on glycosyl bonds; and hemicellulose metabolic processes. The activities of nitrogen metabolic enzymes were highest in A1 (0.39% nitrogen) during the three nitrogen levels (A1, A2 and A3). However, the activities of cellulose enzymes were highest in A3, while the hemicellulase xylanase activity was highest in A1. The DEGs associated with CAZymes, starch and sucrose metabolism and the MAPK signaling pathway were also most highly expressed in A3. These results suggested that increased nitrogen levels can upregulate carbon metabolism in S. rugosoannulata. This study could increase knowledge of the lignocellulose bioconversion pathways and improve biodegradation efficiency in Basidiomycetes.

Genetic and functional analysis of the Zn(II)2Cys6 transcription factor HADA-1 in Hypsizygus marmoreus.

Zn(II)2Cys6 transcription factors are critical for the reproductive growth and sexual development of fungi, but their roles in Basidiomycota remain unclear. In this study, the Hypsizygus marmoreus gene hada-1 was shown to encode a Zn(II)2Cys6 transcription factor, the growth rate of mycelia was decreased, hyphae were angulated, and fruiting body development was hindered in the hada-1-silenced strains. In addition, mitochondrial stability was lost, and the mitochondria morphologies changed from oval shaped to dumbbell or linear shaped in the silenced strains. Regarding mitochondrial instability, the mitochondrial complex II, III, and V activities and adenosine triphosphate content were significantly decreased. At the same time, the activities of the carbohydrate metabolism-related enzymes glucose-6-plosphatase, glucose dehydrogenase, and laccase were significantly decreased, which might have resulted in the reduction of carbon metabolism. Furthermore, hada-1 was shown to regulate the reactive oxygen species (ROS) level; compared with the wild-type (WT) strain, the silenced mycelia exhibited higher ROS contents and were more sensitive to oxidative stress. Taken together, these results indicate that, as a global regulator, hada-1 plays crucial roles in mycelial growth, fruiting body development, carbon metabolism, mitochondrial stability, and oxidative stress in the basidiomycete H. marmoreus. KEY POINTS: • Zn(II)2Cys6 transcription factor, mitochondrial stability, fruiting body development.

The functions of glutathione peroxidase in ROS homeostasis and fruiting body development in Hypsizygus marmoreus.

Glutathione peroxidase (GPX) is one of the most important antioxidant enzymes for maintaining reactive oxygen species (ROS) homeostasis. Although studies on fungi have suggested many important physiological functions of GPX, few studies have examined the role of this enzyme in Basidiomycetes, particularly its functions in fruiting body developmental processes. In the present study, GPX-silenced (GPxi) strains were obtained by using RNA interference. The GPxi strains of Hypsizygus marmoreus showed defects in mycelial growth and fruiting body development. In addition, the results indicated essential roles of GPX in controlling ROS homeostasis by regulating intracellular H2O2 levels, maintaining GSH/GSSG balance, and promoting antioxidant enzyme activity. Furthermore, lignocellulose enzyme activity levels were reduced and the mitochondrial phenotype and mitochondrial complex activity levels were changed in the H. marmoreus GPxi strains, possibly in response to impediments to mycelial growth and fruiting body development. These findings indicate that ROS homeostasis has a complex influence on growth, fruiting body development, GSH/GSSG balance, and carbon metabolism in H. marmoreus.Key points• ROS balance, energy metabolism, fruiting development.

Effects of the rice-mushroom rotation pattern on soil properties and microbial community succession in paddy fields.

Introduction: Currently, straw biodegradation and soil improvement in rice-mushroom rotation systems have attracted much attention. However, there is still a lack of studies on the effects of rice-mushroom rotation on yield, soil properties and microbial succession. Methods: In this study, no treatment (CK), green manure return (GM) and rice straw return (RS) were used as controls to fully evaluate the effect of Stropharia rugosoannulata cultivation substrate return (SRS) on soil properties and microorganisms. Results: The results indicated that rice yield, soil nutrient (organic matter, organic carbon, total nitrogen, available nitrogen and available potassium) and soil enzyme (urease, saccharase, lignin peroxidase and laccase) activities had positive responses to the rice-mushroom rotation. At the interannual level, microbial diversity varied significantly among treatments, with the rice-mushroom rotation significantly increasing the relative alpha diversity index of soil bacteria and enriching beneficial microbial communities such as Rhizobium, Bacillus and Trichoderma for rice growth. Soil nutrients and enzymatic activities were significantly correlated with microbial communities during rice-mushroom rotation. The fungal-bacterial co-occurrence networks were modular, and Latescibacterota, Chloroflexi, Gemmatimonadota and Patescibacteria were closely related to the accumulation of nutrients in the soil. The structural equation model (SEM) showed that fungal diversity responded more to changes in soil nutrients than did bacterial diversity. Discussion: Overall, the rice-mushroom rotation model improved soil nutrients and rice yields, enriched beneficial microorganisms and maintained microbial diversity. This study provides new insights into the use of S. rugosoannulata cultivation substrates in the sustainable development of agroecosystems.

Dynamics of the soil microbial community associated with Morchella cultivation: diversity, assembly mechanism and yield prediction.

Introduction: The artificial cultivation of morels has been a global research focus owing to production variability. Understanding the microbial ecology in cultivated soil is essential to increase morel yield and alleviate pathogen harm. Methods: A total of nine Morchella cultivation experiments in four soil field types, forest, paddy, greenhouse, and orchard in Shanghai city were performed to determine the potential ecological relationship between Morchella growth and soil microbial ecology. Results: Generally, significant variation was observed in the soil microbial diversity and composition between the different experimental field types. The niche width analysis indicated that the bacterial habitat niche breadth was significantly greater than the fungal community width, which was further confirmed by a null model that revealed that homogeneous selection could explain 46.26 and 53.64% of the variance in the bacterial and fungal assemblies, respectively. Moreover, the neutral community model revealed that stochastic processes dominate the bacterial community in forests and paddies and both the bacterial and fungal communities in orchard crops, whereas deterministic processes mostly govern the fungal community in forests and paddies and both the bacterial and the fungal communities in greenhouses. Furthermore, co-occurrence patterns were constructed, and the results demonstrated that the dynamics of the soil microbial community are related to fluctuations in soil physicochemical characteristics, especially soil potassium. Importantly, structural equation modeling further demonstrated that the experimental soil type significantly affects the potassium content of the soil, which can directly or indirectly promote Morchella yield by inhibiting soil fungal richness. Discussion: This was the first study to predict morel yield through soil potassium fertilizer and soil fungal community richness, which provides new insights into deciphering the importance of microbial ecology in morel agroecosystems.

Comparative Transcriptome Profiles of the Response of Mycelia of the Genus Morchella to Temperature Stress: An Examination of Potential Resistance Mechanisms.

Temperature and moisture belong to the most important environmental factors affecting the growth and development of fungi. However, the effect of temperature on the mycelia of the edible Morchella mushrooms has not been determined. Here, a comprehensive analysis was performed to determine the influence of culture temperature on 13 strains of mycelia of three Morchella species (Morchella sextelata, Morchella septimelata, and Morchella importuna) at 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, and 30 °C. The mycelial branching and growth rate data showed that 15-20 °C was a suitable temperature range for the mycelial growth of the 13 Morchella strains. RNA sequences revealed that a total of 2843, 2404, 1973, 1572, and 1866 differentially expressed genes (DEGs) were identified at 5 °C, 10 °C, 15 °C, 25 °C, and 30 °C compared with 20 °C. A Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis further indicated that the purine nucleotide and tyrosine metabolism pathways were crucial for mycelium development. Moreover, the enrichment of autophagy of mitochondria, regulation of cell morphogenesis, and piecemeal microautophagy of the nuclei at 25 °C (vs. 20 °C) indicated the damage caused by heat stress in Morchella mycelia. Notably, a total of four unique module eigengenes (MEs) were identified through a weighted gene coexpression network analysis (WGCNA). Among them, 2293 genes in the turquoise module were significantly positively correlated with temperature (r = 0.946, p < 0.001), whereas 739 genes in the blue module were significantly negatively correlated with temperature (r = -0.896, p < 0.001), suggesting that the effect of high temperatures on mycelial genes was significantly greater than that of low temperatures. Moreover, the coexpression network indicated that high culture temperatures accelerated the oxidative stress response and energy metabolism in mycelia, while upregulation of purine nucleotide catabolism and ribosomal protein-related genes were improved by low-temperature tolerance. In addition, the upregulated expression of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and heat shock protein (HSP) genes in mycelia was associated with reactive oxygen species (ROS)-mediated damage at high temperatures. Overall, this study provides an important theoretical basis and application value for optimizing Morchella cultivation techniques.

Effects of an efficient straw decomposition system mediated by Stropharia rugosoannulata on soil properties and microbial communities in forestland.

Cultivation of Stropharia rugosoannulata with straw in forestland is effective for straw biodegradation and can prevent the waste of straw resources and environmental pollution and generate economic benefits. However, there is a lack of systematic evaluation of spent mushroom substrate (SMS) input into forestland, such as soil properties and microbial succession. In this experiment, 0 (CK), 10 (SA), 20 (SB), 30 (SC), 40 (SD), and 50 (SE) kg/m2 straw were used to cultivate S. rugosoannulata, and two soil layers (0-10 cm, 10-20 cm) of the cultivated forestland were analyzed. The results indicated that SMS significantly promoted nutrient accumulation in forestland. The bacterial alpha diversity in the SC treatment group was greater than that in the control and gradually decreased to the control level with interannual changes, while the trend of fungal alpha diversity was opposite to that of bacterial alpha diversity. Furthermore, the SC treatment group positively affected soil nitrogen metabolism-related microorganisms for two consecutive years and significantly promoted tree growth. Habitat niche breadth and null model analysis revealed that bacterial communities were more sensitive than fungal communities after SMS input. Linear mixed model (LMM) analysis revealed that SMS supplementation significantly positively affected bacteria (Gammaproteobacteria and Bacteroidota) and significantly negatively affected fungi (Coniochaetales). The constructed fungal-bacterial co-occurrence networks exhibited modularity, and the five types of bacteria were significantly correlated with soil organic matter (SOM), soil organic carbon (SOC), available potassium (AK), available phosphorus (AAP) and available nitrogen (AN) levels. The structural equation model (SEM) showed that bacterial diversity responded more to changes in soil nutrients than did fungal diversity. Overall, 30 kg/m2 of straw decomposition and 2 years of continuous cultivation were beneficial to soil health. This study provides new insights into the rational decomposition of straw and maintenance of forestland ecological balance by S. rugosoannulata.

Transcriptomic analysis of Stropharia rugosoannulata reveals carbohydrate metabolism and cold resistance mechanisms under low-temperature stress.

Low temperature is an important environmental factor that restricts the growth of Stropharia rugosoannulata; however, the molecular mechanisms underlying S. rugosoannulata responses to low-temperature stress are largely unknown. In this study, we performed a transcriptome analysis of a high-sensitivity strain (DQ-1) and low-sensitivity strain (DQ-3) under low-temperature stress. The liquid hyphae of S. rugosoannulata treated at 25 °C and 10 °C were analyzed by RNA-Seq, and a total of 9499 differentially expressed genes (DEGs) were identified. GO and KEGG enrichment analyses showed that these genes were enriched in "xenobiotic biodegradation and metabolism", "carbohydrate metabolism", "lipid metabolism" and "oxidoreductase activity". Further research found that carbohydrate enzyme (AA, GH, CE, and GT) genes were downregulated more significantly in DQ-1 than DQ-3 and several cellulase activities were also reduced to a greater extent. Moreover, the CAT1, CAT2, GR, and POD genes and more heat shock protein genes (HSP20, HSP78 and sHSP) were upregulated in the two strains after low-temperature stress, and the GPX gene and more heat shock protein genes were upregulated in DQ-3. In addition, the enzyme activity and qRT-PCR results showed trends similar to those of the RNA-Seq results. This result indicates that low-temperature stress reduces the expression of different AA, GH, CE, and GT enzyme genes and reduces the secretion of cellulase, thereby reducing the carbohydrate metabolism process and mycelial growth of S. rugosoannulata. Moreover, the expression levels of different types of antioxidant enzymes and heat shock proteins are also crucial for S. rugosoannulata to resist low-temperature stress. In short, this study will provide a basis for further research on important signaling pathways, gene functions and variety breeding of S. rugosoannulata related to low-temperature stress.

Transcriptome and Differentially Expressed Gene Profiles in Mycelium, Primordium and Fruiting Body Development in Stropharia rugosoannulata.

Stropharia rugosoannulata uses straw as a growth substrate during artificial cultivation and has been widely promoted in China. However, its fruiting body formation and development processes have not been elucidated. In this study, the developmental transcriptomes were analyzed at three stages: the mycelium (G-S), primordium (P-S) and fruiting body (M-F) stages. A total of 9690 differentially expressed genes (DEGs) were identified in the different developmental stages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that these DEGs were involved mainly in hydrolase activity, structural molecule activity and oxidoreductase activity as well as xenobiotic biodegradation and metabolism and energy metabolism pathways. We further found that the higher expression of most carbohydrate enzyme (i.e., GH, CE, CBM, AA and PL) genes in the hyphal (i.e., G-S) stage was related mainly to substrate degradation, while the upregulation of glycosyltransferase (GT) gene expression in the P-S and M-F stages may be related to cell wall synthesis. In addition, we found that CO2-sensing-related genes (i.e., CA-2, CA-3, PKA-1 and PKA-2) were upregulated in the P-S and M-F stages, heat shock protein genes (HSP60 and HSP90) were significantly downregulated in the P-S stage and upregulated in the M-F stage and the transcription factors (i.e., steA, MYB, nosA, HAP1, and GATA-4/5/6) involved in growth and development were significantly upregulated in the P-S stage. These results suggest that environmental factors (i.e., CO2 and temperature) and transcription factors may play a key role in primordium formation. In short, this study provides new insights into the study of stimulating primordia formation affecting the development of fruiting bodies of S. rugosoannulata.

Association of Dietary Micronutrient Intake with Pulmonary Tuberculosis Treatment Failure Rate: ACohort Study.

Malnutrition is associated with an increased risk of pulmonary tuberculosis (PTB) treatment failure. Currently, there is no effective adjunctive nutritional therapy. The current objective is to investigate the association of dietary micronutrient intake with PTB treatment outcome.A cohort study including 1834 PTB patients was conducted in Linyi, China. The dietary micronutrient intake was assessed through a three-day 24 h dietary recall questionnaire. The treatment outcome was assessed by combinations of sputum smear and computerized tomography results. A multivariate binary regression model was used to assess the associations. The final model was adjusted for potential confounding factors. A low intake of vitamin C (adjusted OR (95% CI): 1.80 (1.07, 3.04), Ptrend = 0.02) and Zn (adjusted OR (95% CI): 2.52 (1.25, 5.08), Ptrend = 0.02) was associated with a high treatment failure rate. In addition, a low intake of vitamin C and Mn was associated with a severe tuberculosis symptom, as indicated by a high TB score. A supplementation of vitamin C and Zn may be beneficial in PTB treatment. Previous meta-analysis of randomized controlled trials (RCTs) reported a null effect of Zn supplementation on PTB treatment. The effect of vitamin C supplementation should be investigated by RCTs.

Exogenous l-ascorbic acid regulates the antioxidant system to increase the regeneration of damaged mycelia and induce the development of fruiting bodies in Hypsizygus marmoreus.

Hypsizygus marmoreus is an important commercial edible fungus, but the lack of basic studies on this fungus has hindered further development of its commercial value. In this study, we found that the treatment of damaged vegetative mycelia with 1 mM l-ascorbic acid (ASA) significantly increased the antioxidant enzyme activities (GPX, GR, CAT and SOD) and antioxidant contents (GSH and ASA) and reduced the ROS levels (H2O2 and O2-) in mechanically damaged mycelia. Additionally, this treatment increased mycelial biomass. At the reproductive stage, our results demonstrated that the treatment of damaged H. marmoreus mycelia with 2.24 mM ASA significantly increased the antioxidant enzyme activities (GPX, GR, GST, TRXR and CAT), endogenous ASA contents and GSH/GSSG ratios in different developmental stages and significantly decreased the MDA and H2O2 contents. Furthermore, this study showed that the expression levels of the antioxidant enzyme genes were consistent with the enzyme activities. Damaged mycelia treated with ASA regenerated 2-3 d earlier than the control group and showed significantly enhanced fruiting body production. These results suggested that exogenous ASA regulated mycelia intracellular ASA content to increase mycelial antioxidant abilities, induce the regeneration of damaged mycelia and regulate the development of fruiting bodies in H. marmoreus.

Efficacy of proprietary Lactobacillus casei for anti-tuberculosis associated gastrointestinal adverse reactions in adult patients: a randomized, open-label, dose-response trial.

Anti-tuberculosis (TB) drugs can induce a series of gastrointestinal adverse events, which can seriously affect patients' quality of life and may lead to treatment failure. Studies have shown that probiotics treatments can improve antibiotic-induced gastrointestinal symptoms. In this randomized, open-label, dose-response clinical trial, we investigated the preventive effects of Lactobacillus casei on anti-TB-induced gastrointestinal adverse events. In total, 429 adult patients who underwent intensive-phase anti-TB therapy were included and randomly assigned to consume one bottle of L. casei of per day (low-dose group, n = 142), two bottles of L. casei per day (high-dose group, n = 143), or no intervention (control group, n = 144) for 2 months. Each bottle of L. casei contained 10 billion colony-forming units of live L. casei. Patients' daily gastrointestinal symptoms were recorded during the intervention period. After 2 months of L. casei consumption, 397 patients had completed the intervention. Both the high and low dose L. casei groups (37.6% and 29.4%, respectively) had lower incidences of anti-TB-associated total gastrointestinal adverse events than the control group (50.0%). The high and low dose L. casei groups (3.5 d and 5.8 d, respectively) also had shorter duration anti-TB-associated adverse gastrointestinal symptoms than the control group (6.2 d). Regarding individual symptoms, the higher L. casei dose resulted in a lower incidence of vomiting and appetite loss. Similar dose-dependent protective effects of L. casei were observed regarding the duration of vomiting and appetite loss. These findings indicated that daily L. casei consumption prevented anti-TB-associated gastrointestinal adverse events. This trial was registered at the Chinese Clinical Trial Register (ChiCTR-IOR-17013210).

Correction: Efficacy of proprietary Lactobacillus casei for anti-tuberculosis associated gastrointestinal adverse reactions in adult patients: a randomized, open-label, dose-response trial.

Correction for 'Efficacy of proprietary Lactobacillus casei for anti-tuberculosis associated gastrointestinal adverse reactions in adult patients: a randomized, open-label, dose-response trial' by Song Lin et al., Food Funct., 2020, 11, 370-377.

Comparative transcriptome analysis reveals potential fruiting body formation mechanisms in Morchella importuna.

Morchella importuna has been artificially cultivated, but stable production remains difficult because its mechanisms of fruiting body formation are unclear. To investigate the fruiting body formation mechanisms, we sequenced the transcriptomes of Morchella importuna at the mycelial and young fruiting body stages. Among the 12,561 differentially expressed genes (DEGs), 9215 were upregulated, and 3346 were downregulated. DEG enrichment analysis showed that these genes were enriched in the "generation of precursor metabolites and energy", "carbohydrate catabolic process", and "oxidoreductase activity" Gene Ontology (GO) functional categories. Enzyme activity assay results indicated that the activity levels of CAZymes (carbohydrate-active enzymes), oxidoreductases (SOD (superoxide dismutase), CAT (catalase)) and mitochondrial complex (complex I, II, III) proteins were significantly increased from the mycelial stage to the young fruiting body stage. In addition, the genes encoding CAZymes, mitochondrial proteins, oxidoreductases and heat shock proteins had higher expression levels in the young fruiting body stage than in the mycelial stage, and the qRT-PCR results showed similar trends to the RNA-Seq results. In summary, these results suggest that carbohydrate catabolism and energy metabolism are significantly enhanced in the young fruiting body stage and that growth environment temperature changes affect the formation of fruiting bodies.

Hydrogen-rich water alleviates the toxicities of different stresses to mycelial growth in Hypsizygus marmoreus.

In plants, hydrogen gas (H2) enhances tolerance to several abiotic stresses, including salinity and heavy metals. However, the effect of H2 on fungal growth under different stresses remains largely unclear. In this study, hydrogen-rich water (HRW) was employed to characterize physiological roles and molecular mechanisms of H2 in the alleviation of three different stresses in basidiomycete Hypsizygus marmoreus. Our results showed that HRW treatment, of which the H2 concentration was 0.8 mM, significantly reduced the toxicities of CdCl2, NaCl and H2O2, leading to significantly improved mycelial growth and biomass. These beneficial effects could be attributed to a significantly decreased formation of malondialdehyde (MDA). Besides, HRW treatment significantly increased the activities of antioxidants (SOD, CAT and GR) as well as the gene expressions of these antioxidants (SOD, CAT, and GR) at the mRNA level. In vivo detection of reactive oxygen species (ROS), including H2O2 and O2-, as well as lipid peroxidation provided further evidence that HRW could significantly improve tolerances of CdCl2, NaCl and H2O2. Furthermore, pyruvate kinase was activated in the mycelia treated with HRW, along with its induced gene expression, suggesting that HRW treatment enhanced the glucose metabolism. Taken together, our findings suggested that the usage of HRW could be an effective approach for contaminant detoxification in H. marmoreus, which was similar with the effects of HRW in plants, and such effects could be also beneficial in entire agricultural system.

Kojic acid-mediated damage responses induce mycelial regeneration in the basidiomycete Hypsizygus marmoreus.

Mechanical damage can induce fruiting body production in fungi. In this study, the antioxidant kojic acid (KA) was found to enhance injured mycelial regeneration and increase fruiting body production in Hypsizygus marmoreus. KA reduced the level of reactive oxygen species (ROS), which are harmful to mycelia when excessively generated by mechanical damage. Moreover, KA increased catalase and superoxide dismutase activities and glutathione and ascorbic acid contents by up-regulating antioxidant gene expression. These results suggest that KA promotes mycelial regeneration in response to damage by activating a "stress signal" and enhances the ability of H. marmoreus to resist oxidative damage by invoking the antioxidant system. In addition, KA increased the content of extracellular ATP, which serves as a "stress signal" in response to injury, and modulated ROS signaling, decreasing NADPH oxidase gene expression and ROS levels in the mycelial-regeneration stage. KA treatment also up-regulated the MAPK, Ca2+ and oxylipin pathways, suggesting their involvement in the damage response. Furthermore, laccase and cellulase activities were stimulated by KA at different developmental stages. These results demonstrate that KA regulates gene expression and activates pathways for mycelial wound healing, regeneration of damaged mycelia and reproductive structure formation in the basidiomycete H. marmoreus.

Hydrogen-rich water increases postharvest quality by enhancing antioxidant capacity in Hypsizygus marmoreus.

In the present study, we aimed to assess the effect of hydrogen-rich water (HRW) on the physicochemical characteristics and antioxidant capacity of Hypsizygus marmoreus during 12 days of postharvest storage at 4 °C. Different concentrations of HRW (25, 50 and 100%) were tested, and our data showed that 25% HRW treatment had the most significant effect on preservation of nutrients in H. marmoreus compared with the control group. In addition, 25% HRW treatment significantly reduced the relative electrolyte leakage rate and malonaldehyde (MDA) content (P < 0.05) and increased anti-superoxide-radical (O2-) activity compared with the control group. The activities of antioxidants, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) were activated by 25% HRW treatment, and the expression levels of these genes were also induced. These results suggested that HRW treatment could delay rot incidence in mushrooms during storage by regulating antioxidant defense ability. This study supplies a new and simple method to maintain the quality and extend the shelf life of mushrooms.