Search Results (434)

Despite increasing interest in fungal remediation systems for the treatment of persistent contaminants, the mechanisms governing fungal transformation of halogenated organic compounds remain poorly resolved. The aim of this study was to determine whether the transformation of halogenated nitrophenols is driven by isolated extracellular enzymes and cofactor-dependent oxidative activity or instead reflects coordinated system-level fungal metabolism. To address this question, we investigated the transformation of 2-chloro-4-nitrophenol (2C4NP) and 5-fluoro-2-nitrophenol (5F2NP) by ascomycete fungi Caldariomyces fumago (C. fumago) and Curvularia sp. under varying nutrient and cofactor conditions. Whole-culture transformation, crude supernatant activity, purified enzyme assays, intracellular detoxification responses, and genome-resolved functional annotation were integrated to evaluate the relative contributions of extracellular and intracellular processes. Transformation was strongly dependent on fungal species, substrate identity, nutrient availability, and cofactor composition. C. fumago achieved complete transformation of 2C4NP and up to 85.3% transformation of 5F2NP, whereas Curvularia sp. exhibited strict Na₃VO₄-dependent transformation of 5F2NP. Crude supernatants retained partial transformation capacity, achieving ~40–45% substrate depletion under conditions supporting whole-culture activity. Purified chloroperoxidase and laccase showed negligible independent activity and did not reproduce whole-culture transformation behavior. Lignin peroxidase activity was consistently induced during contaminant exposure and peaked during periods of maximum transformation. Cytochrome P450 inhibition did not prevent transformation. Baseline glutathione S-transferase activity was detected in both fungi, and comparative genome analysis identified conserved intracellular detoxification-associated enzyme alongside divergent extracellular oxidative enzyme repertoires. Together, these findings demonstrate that transformation of halogenated nitrophenols by fungi cannot be explained by isolated extracellular enzymes alone but is consistent with coordinated extracellular and intracellular system-level metabolism. These findings highlight an underexplored role for integrated fungal metabolic systems in bioremediation and provide a mechanistic basis for developing a scalable fungal platform for treatment of persistent halogenated contaminants. Full article

Hypogeous ascomycetous fungi (truffles) are challenging to study because they produce underground sporocarps that may not be encountered during traditional fungal surveys. Genea is one such genus that has garnered considerable attention over the past decades due to its role as an ectomycorrhizal partner and contribution to nutrient cycling and ecosystem stability. Yet, very limited information is available about its taxonomy, phylogeny and ecology worldwide. The current study aims to expand the known distribution of Genea species in Central Europe by integrating morphological, molecular and ecological analyses of new collections as well as the assessment of herbarium materials. Light microscopy and SEM were used to determine morphological characteristics along with FT-IR (Fourier transform infrared) spectroscopy measurements, which proved to be a powerful tool for species differentiation. Molecular phylogenetic analyses were conducted using the internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) and D1/D2 domain of the large subunit (28S) of nuclear ribosomal DNA sequences to confirm species identity. In this study, a new species, Genea szemereiensis, along with the first report of Genea pinicola from Hungary, was made. In addition, the ecological parameters of the species, including habitat, altitude, soil nutrients and pH, were revised, which has not been reported previously in detail for this genus. Full article

Rice false smut (RFS) caused by the ascomycete Ustilaginoidea virens (teleomorph: Villosiclava virens) is a destructive fungal disease all over the world. The RFS balls are ball-like colonies transformed from individual grains through the infection of U. virens. The sclerotia, which are dormant structures, typically generate from the late-stage RFS balls, and produce ascospores that play a dominant role in the life cycle of the pathogen. U. virens can produce mycotoxins, mainly including ustiloxins and ustilaginoidins, that are toxic to rice plants and animals and pose a serious threat to their health. Though ustiloxins and ustilaginoidins have been isolated from the RFS balls, their distribution and contents in the sclerotia remain unclear. In this study, a systematic content analysis of main mycotoxins was conducted on the sclerotia and other parts of the late-stage RFS balls. Ustiloxins were predominantly found in the sclerotia and middle layer, whereas ustilagnoidins mainly accumulated in the outer and middle layers and rarely accumulated in the sclerotia and inner layer of RFS balls. The findings were further supported by transcriptome and RT–qPCR analysis data. The different accumulation and distribution of these two kinds of mycotoxins in the sclerotia and other parts of the RFS balls may be related to their specific physiological functions and deserve further investigation. Full article

The circadian clock is a widespread rhythmic phenomenon across organisms, characterized by distinct gene expression patterns and behaviors at specific times of the day. Extensive genetic studies in the model fungus Neurospora crassa have yielded critical insights into the components and molecular mechanisms of circadian oscillators. However, these understandings remain absent across fungal lineages, especially from edible mushrooms. Morels (Morchella spp.) are well-recognized edible ascomycetes of considerable economic value and are partially artificially cultivated, but their biological characteristics are poorly understood. Investigating the presence of their circadian clock components, as well as the molecular underpinnings of circadian rhythms, holds important biological implications. In this study, we firstly performed a genomic search for homologs of known circadian clock genes in Morchella sextelata. Homologs of seven circadian clock genes, including wc-1, wc-2, fwd-1, frh, frq, and two additional clock-controlled genes, were identified, indicating the components necessary for the operation of a FWC oscillator contained in M. sextelata. Then, using reverse transcription quantitative PCR (RT-qPCR), the expression profiles of these seven circadian clock-related genes and four mating-type genes were examined in RNA samples which were extracted from mycelia of MAT1-1, MAT1-2 and MAT1-1 × MAT1-2 co-culture/crossed condition during conidiation under in vitro cultivation across one day. The expression levels of seven circadian clock genes and four mating-type genes displayed similar time-of-day-specific rhythmic patterns, yet remained consistently distinct across the mating-type strains and their co-culture/crossed condition, indicating a potential correlation between circadian clock and mating-type loci. Collectively, these results suggest that M. sextelata harbors conserved circadian clock-related homologs and displays mating-type-associated temporal expression differences under the tested conidiation conditions, offering a novel perspective for exploring the potential link between clock-related regulation and mating-type background in the future. Full article

Cordyceps militaris is a well-known edible and medicinal entomopathogenic fungus that can be cultivated using silkworm larvae as hosts. However, no reports have been found regarding the gut microbiota of silkworms (Bombyx mori) following C. militaris injection. Based on three biological replicates, illumina 16S rRNA gene sequencing was used to investigate the changes over time in the gut bacteria and fungi of silkworms injected with C. militaris. The results indicated that following inoculation with C. militaris, the abundance of Bacillales and Basidiomycetes increased, while that of Pseudomonadales and Ascomycetes decreased. The abundance of Mammaliicoccus increased by 78% and 26% in dying silkworms compared to their pre-inoculated counterparts and blank control group, respectively. The relative abundance of Rhodotorula in dying silkworms was 2.89-fold and 80.51-fold higher than that in the pre-inoculation group and blank control group, respectively. After inoculation with C. militaris, fungi showed the greatest community variations at day 2, while bacteria displayed the most distinct differences at day 4. Under C. militaris infection, the abundance of all four pathways of Genetic Information Processing in silkworm larvae’s gut microbiota significantly increased. Taken together, the results demonstrate that inoculation with C. militaris induced significant alterations in the composition, structure, assembly, and predictive functional profiles of gut bacteria and fungi in silkworms. This study provides a theoretical basis for exploring the production of C. militaris using silkworm larvae as insect hosts. Full article

The biosynthetic gene cluster (BGC) responsible for producing diaporthinic acid has remained genetically unassigned despite repeated isolation of this metabolite from several fungal species. In this study, we activated the dia BGC in Trichoderma reesei by overexpressing the cluster-associated zinc cluster protein DiaR1 to identify the BGC’s in vivo metabolic output and reconstruct the corresponding biosynthetic pathway. Metabolite production was analyzed by HPLC-MS/MS, and the major product was isolated and structurally confirmed by NMR spectroscopy. Individual genes of the dia cluster were deleted in the activated background to assess their functional roles, and transcript levels were quantified by RT-qPCR. Activation of the cluster resulted in the predominant accumulation of diaporthinic acid, accompanied by several related isocoumarin derivatives, while antibacterial and antifungal assays showed no detectable activity of diaporthinic acid under the tested conditions. Deletion analyses demonstrated that the polyketide synthase Dia1, the bifunctional halogenase/methyltransferase Dia5, and the FAD-dependent oxidoreductase Dia4 are essential for diaporthinic acid formation, whereas Dia2 and Dia3 are dispensable in vivo despite the previously proposed roles of their Aspergillus oryzae homologs based on in vitro studies. On the basis of intermediate accumulation patterns, we propose that Dia4 catalyzes the oxidation of dichlorodiaporthin to diaporthinic acid. Together, these results genetically link diaporthinic acid to the dia BGC and refine the previously proposed biosynthetic model derived from A. oryzae. Full article

The cell wall (CW) of Mucoromycota has a unique chitin/chitosan complex, unlike chitin/glucan complex in Ascomycota. Under cell wall stress (CWS), induced by azo dyes, ascomycetes increase the amount of CW chitin. This study analyzes the response of Mucor flavus to CWS, induced by Congo red and Calcofluor white. It was found that azo dyes significantly reduced the biomass yield and inhibited apical growth and branching but did not lead to an increase in the amount of CW chitin/chitosan, neutral polysacchrides and cytosol osmolytes. Non-bilayer phosphatidic acids and phosphatidylethanolamines dominated in the control membrane lipids, but the proportion of bilayer phosphatidylcholines did not exceed 5%. Under CWS, the proportion of phosphatidic acids increased, while the proportion of phosphatidylethanolamines decreased and the degree of unsaturation of phospholipids increased. Storage lipids in the control were represented by mono-, di- and triacylglycerides and free fatty acids. Under CWS, the proportion of diacylglycerides increased significantly, while the proportion of triacylglycerides decreased. Thus, the CWS response of M. flavus consisted of significant changes in growth and the composition of membrane and storage lipids, but the amount of CW chitin/chitosan and cytosol osmolytes did not increase, which is different from the response of ascomycetes. Full article

Chocolate spot, caused by the ascomycete fungus Botrytis fabae, is a devastating foliar disease and a major constraint on the quality and yield of faba beans (Vicia faba). Monoterpenes, such as carvone, cineole, and linalool, are often considered natural-identical alternatives to synthetic chemicals. Therefore, this study was carried out to assess the antifungal activity of some eco-friendly control agents (carvone, cineole, and linalool) against B. fabae, the causative agent of chocolate spot disease in faba beans, through growth inhibition assays in vitro. Furthermore, the efficacy of the tested monoterpenes for reducing the severity of chocolate spot disease in faba beans was evaluated under field conditions. Moreover, these eco-friendly control agents activate plant defense enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase) as a self-defense mechanism against pathogen attacks of faba bean plants were investigated. Moreover, the impact of the tested monoterpenes on growth and yield characters of faba bean was evaluated. The results indicated a significant decrease in B. fabae growth following a treatment with the tested compounds compared to untreated controls. In field trials, treated faba bean plants exhibited a notable reduction in disease severity. Additionally, the application of monoterpenes enhanced the activity of defense enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase), which are integral to plant defense mechanisms. Treatments also resulted in significant improvement growth and yield characters of faba bean. These findings suggest that the tested monoterpenes could serve as a control strategy for managing B. fabae, offering an environmentally sustainable alternative to conventional fungicides. Full article

Ochetobibus elongatus (Kner) is a migratory fish found in the Yangtze River basin and areas south of it, and listed as a critically endangered (CR) fish on the China Red List of Vertebrates. To achieve group recovery and artificial breeding, this study investigated the dietary characteristics of O. elongatus based on high-throughput sequencing of its intestinal contents, and its digestive system morphology, and its histology. Results showed that the digestive system of O. elongatus lacked a stomach and mainly consisted of the oropharynx, pharyngeal teeth, esophagus, intestine, and anus. The gut index was 0.88, with clear segmentation of the foregut, midgut, and hindgut, and the visceral mass index was 7.35%. Histological analysis of the digestive system revealed the presence of keratinized dental plates or pharyngeal teeth in the pharynx, as well as a high density of taste bud cells in the soft palate of the oral cavity. The surface layer of the intestinal villi contained numerous mucous cells, with the average number of mucous cells per villus gradually increasing from the esophagus to the hindgut, and the foregut having the longest and most abundant mucosal folds. The esophagus exhibited well-developed circular and longitudinal muscle layers, while in the hindgut, both the circular and longitudinal muscle layers were slightly thicker than those in the midgut. High-throughput sequencing of the intestinal contents of O. elongatus revealed the following phyla based on 18S V4 meta-barcoding: Chlorophyta, Diatoms, Arthropoda, Basidiomycetes, and Ascomycetes, with the genus Hypophthalmichthys and algae being the main classifications. In contrast, based on COI meta-barcoding, the study newly identified the phyla Cnidaria and Mollusca, with the genera Chlorophyta, Scenedesmus, Pectinodesmus, and zooplankton such as Pseudodiaptomus. Metagenomic sequencing revealed that the gut microbiota at the phylum level was predominantly composed of Pseudomonadota, Ascomycota, Basidiomycota, Chytridiomycota, and Bacillota, with key genera including Cetobacter, Pseudomonas, Acinetobacter, Aeromonas, and Clostridium. This study indicates that O. elongatus is an omnivore with carnivorous tendencies. Basic biological research on O. elongatus is of great significance for the restoration of the population, artificial breeding, and the development of its artificially formulated feed. It also provides important data for the formulation of biodiversity conservation measures. Full article

This study investigated the secondary fermentation of cocoa beans using mushrooms to further improve the quality of beans. Cocoa beans were fermented using 42 species of basidiomycetes and ascomycetes. Mycelial growth was observed in 29 strains. When 75% cocoa chocolate was prepared using the cocoa beans in which mycelial growth was observed, theobromine concentration was higher in 17 strains compared with the control. Furthermore, caffeine concentration was similar to or lower than the control in all strains. Chocolate produced using cocoa beans fermented with particularly Polyporus arcularius, Peziza vesiculosa, and Urnula craterium exhibited significantly higher theobromine concentrations. Compared to the control theobromine concentration of 7.53 mg/g, P. arcularius showed 9.25 mg/g, 9.13 mg/g for P. vesiculosa, and 9.05 mg/g for U. craterium. Furthermore, the reducing sugar concentration and total polyphenol concentration increased, and the antioxidant activity was similar to or higher than that of the control. These results suggest that secondary fermentation using mushrooms could be used to develop chocolate characterized by high theobromine, low caffeine, and rich polyphenol content. Full article

The discovery of bidirectional microRNA transfer between two organisms during plant–microbe interactions and the ability of some fungal pathogens to absorb double-stranded RNA (dsRNA) or short interfering RNA (siRNA) from the environment provided an impetus for exploiting this mechanism in plant defense against pathogens. In this study, we investigated the role of conserved wheat microRNAs (miRNAs), miRNA408 and miRNA159, in inducing plant defense responses and suppressing the virulence of the phytopathogenic ascomycete fungus Parastagonospora nodorum, mediated by necrotrophic effectors (NEs) encoded by SnTox genes regulated by fungal transcription factors (TFs). The foliar spraying with in vitro synthesized siRNA408 and siRNA159 duplexes before inoculation with SnTox3-producing P. nodorum isolate increased wheat plant resistance to the SnB isolate and suppressed the pathogen growth and development. Most likely, silencing of the miRNA408 target genes TaCAT-2A, TaCAT-2B, and TaCLP1, and the miRNA159 target gene TaMYB65, led to the induction of a defense response of wheat plants against P. nodorum. This defense response was characterized by a decrease in the catalase activity, accumulation of hydrogen peroxide, activation of the expression of salicylic acid signaling pathway genes (TaWRKY13, TaPR1), and suppression of the expression of ethylene signaling pathway genes (TaEIN3, TaPR3). We demonstrated for the first time the ability of siRNA159 and siRNA408 to penetrate the mycelium of the pathogen P. nodorum and be involved in the cross-kingdom regulation of fungal genes to suppress the expression of some genes of NE (SnToxA, SnTox3) and fungal TFs (SnStuA). We predicted potential targets for wheat miRNA408 and miRNA159 in the P. nodorum transcriptome, making spray-induced gene silencing (SIGS) promising for use against this pathogen. These results provide valuable insights for studying the cross-kingdom transfer of plant miRNAs. Full article

Phytopathogenic Ascomycetes Blumeria graminis f. sp. tritici (Bgt) causes wheat powdery mildew disease and impacts global wheat production. Decoding the molecular wheat-Bgt interaction could facilitate the wheat disease resistance breeding. In this study, we elucidated that wheat histone deacetylase 19 (TaHDA19) regulates susceptibility to Bgt pathogen by suppressing biosynthesis of cuticular wax and salicylic acid (SA). Knockdown of wheat TaHDA19 gene expression led to in enhanced cuticular wax and SA accumulation, potentiated Bgt conidia germination and appressoria formation, attenuated formation of Bgt haustoria and microcolonies. Histone deacetylase TaHDA19 is enriched at the TaECR and TaSARD1 promoter regions to facilitate histone deacetylation, and thus suppressing TaECR and TaSARD1 transcription. In addition, we identified cuticular wax and SA regulated by TaHDA19 as chemical cues determining wheat pre- and postsusceptibility to Bgt pathogen. These findings collectively support that the wheat histone deacetylase TaHDA19 epigenetically suppresses cuticular wax and SA biosynthesis, thereby dampening chemical cues essential for the wheat powdery mildew susceptibility. Full article

Xylaria karsticola NBIMCC 9097 is a recently described and rare fungicolous species originating from Bulgaria. Understanding its growth behavior and bioactive potential is essential for evaluating its biotechnological and pharmaceutical relevance. In the presented study, we model the in vitro growth kinetics of X. karsticola mycelium under submerged cultivation and assess its antimicrobial activity. Optimization of MCM and MYB media markedly increased biomass yields to 20.11 and 23.25 g/dm³, respectively, compared with non-optimized media (9.9 ± 0.21 and 10.8 ± 0.28 g/dm³). The maximum specific growth rate was higher in the MCM (0.803 ± 0.004 h⁻¹) in comparison with the MYB medium (0.711 ± 0.003 h⁻¹); however, the MYB medium supported greater biomass accumulation and more efficient substrate utilization, reflected by a higher utilization coefficient (0.9900 ± 0.001 versus 0.9644 ± 0.005). The antimicrobial activity was evaluated using agar disk diffusion and minimum inhibitory concentration assays against Gram-positive and Gram-negative bacteria and yeasts. Hexane and ethyl acetate extracts were most effective against Pseudomonas aeruginosa ATCC 9027 (MIC 0.067 and 0.059 mg/cm³), while notable anti-yeast activity was observed, particularly against Wickerhamomyces anomalus, Saccharomycodes ludwigii, and Pichia membranifaciens. The lowest MIC (0.02 mg/cm³) was recorded for the water biomass extract against S. ludwigii indicating potent antimicrobial activity against the tested microorganism. These findings identify X. karsticola as a potential source of antimicrobial metabolites and provide a strong motivation for comprehensive metabolomic profiling and systematic optimization of its cultivation. Full article

Morchella is a nutritious and artificially cultivable rare ascomycete, and its growth and development regulation mechanisms are a current research hotspot. High-temperature stress severely limits the annual yield of Morchella, and this challenge is intensifying with global warming. However, previous studies have lacked systematic screening for heat-tolerant Morchella strains, and their molecular response mechanisms to heat stress remain unclear. In this study, we conducted a comprehensive analysis of phenotypic characteristics, physiological metabolism, and transcriptomics on 19 Morchella strains under normal (25 °C) and high-temperature (30 °C) conditions. The heat-tolerant strain HLM exhibited superior performance in mycelial growth, morphology, and field cultivation. It maintained cell homeostasis under heat stress through mild osmotic regulation (elevated levels of proline, soluble sugars, and proteins), a robust antioxidant system (increased activities of CAT, POD, and SOD), and reduced malondialdehyde accumulation. Transcriptomic analysis identified a novel regulatory model of “stress perception—metabolic preparation—terminal detoxification” in the heat-tolerant strain HLM under heat stress. The rapid upregulation of the SMPD1 gene may mediate ceramide signal generation, promoting G6PDH expression to drive carbon flow into the pentose phosphate pathway, thereby increasing NADPH output. As the detoxification terminal, AKR4C uses this reducing power to eliminate toxic carbonyl end products like malondialdehyde, completing the defense loop. These findings offer new insights into the heat-tolerance mechanisms of large ascomycetes, provide a theoretical foundation for stress-resistant Morchella breeding and cultivation in high-temperature areas, and serve as valuable resources for exploring heat-tolerance mechanisms and molecular breeding in other edible fungi. Full article

The ascomycete fungus Clonostachys rosea is a promising biocontrol agent against root-knot nematodes. To develop a more effective and stable biocontrol strategy, we rationally constructed a co-culture system by partnering C. rosea with the plant growth-promoting bacterium Bacillus velezensis. Through systematic optimization of the medium and inoculation protocol, the co-culture demonstrated significantly enhanced performance, achieving 95.3% mortality of Meloidogyne incognita juveniles, a 78.0% increase in tomato shoot dry weight, and 69.2% disease control efficacy in pot trials. Metabolomic profiling indicated that the co-culture triggered a distinct metabolic profile compared to the respective monocultures. The enhanced efficacy was associated with the accumulation of two functional metabolite groups. First, the co-culture synergistically accumulated direct-effect compounds with reported nematicidal (e.g., daidzin, L-tryptophan) and plant-growth-promoting (e.g., isopentenyladenine, melatonin, and indole-3-propionic acid) activities. In parallel, L-proline emerged as a critical microbial interaction modulator. Targeted quantification showed a clear proline abundance gradient: highest in the C. rosea monoculture, intermediate in co-culture, and lowest in the B. velezensis monoculture. This gradient suggests that proline produced by C. rosea is likely utilized by B. velezensis, a finding further supported by the observation that proline enhanced bacterial biofilm formation and upregulated the matrix genes epsC and tasA. Accordingly, the co-culture itself formed significantly more robust biofilms. Thus, the enhanced biocontrol can be attributed to synergistic metabolite accumulation together with proline-mediated fitness gains in the bacterial partner, establishing a metabolic basis for rationally engineering microbial consortia. Full article