Journal of Fungi

Fusarium avenaceum is an aggressive pathogen of pulse crops and a causal agent in root rot disease that negatively impacts Canadian agriculture. This study reports the results of a targeted metabolomics-based profiling of secondary metabolism in an 18-strain panel of Fusarium avenaceum cultured axenically in multiple media conditions, in addition to an in planta infection assay involving four strains inoculated on two pea cultivars. Multiple secondary metabolites with known roles as virulence factors were detected which have not been previously associated with F. avenaceum, including fungal decalin-containing diterpenoid pyrones (FDDPs), fusaoctaxins, sambutoxin and fusahexin, in addition to confirmation of previously reported secondary metabolites including enniatins, fusarins, chlamydosporols, JM-47 and others. Targeted genomic analysis of secondary metabolite biosynthetic gene clusters was used to confirm the presence/absence of the profiled secondary metabolites. The detection of secondary metabolites with diverse bioactivities is discussed in the context of virulence factor networks potentially coordinating the disruption of plant defenses during disease onset by this generalist plant pathogen. Full article

Aspergillus fumigatus is intrinsically resistant to the widely used antifungal fluconazole, and therapeutic failure can result from acquired resistance to voriconazole, the primary treatment for invasive aspergillosis. The molecular basis of substrate specificity and innate and acquired resistance of A. fumigatus to azole drugs were addressed using crystal structures, molecular models, and expression in Saccharomyces cerevisiae of the sterol 14α-demethylase isoforms AfCYP51A and AfCYP51B targeted by azole drugs, together with their cognate reductase AfCPRA2 and AfERG6 (sterol 24-C-methyltransferase). As predicted by molecular modelling, functional expression of CYP51A and B required eburicol and not lanosterol. A crowded conformationally sensitive region involving the BC-loop, helix I, and the heme makes AfCYP51A T289 primarily responsible for resistance to fluconazole, VT-1161, and the agrochemical difenoconazole. The Y121F T289A combination was required for higher level acquired resistance to fluconazole, VT-1161, difenoconazole, and voriconazole, and confirms posaconazole, isavuconazole and possibly ravuconazole as preferred treatments for target-based azole-resistant aspergillosis due to such a combination of mutations. Full article

Monascus species are known to produce various secondary metabolites with polyketide structures, including Monacolins, pigments, and citrinin. This study investigates the effects of 5-azacytidine on Monascus M1 and RP2. The dry weight, red, yellow, and orange pigment values, and Monacolin K yield of both Monascus strains were measured, and their hyphae observed through electron microscopy. The experimental group showed higher dry weights and pigment values than the control group for both strains. However, Monacolin K production increased substantially only for Monascus M1. Electron micrographs revealed surface wrinkles and large protrusions in both strains after 5-azacytidine treatment. As a potent DNA methylation-promoting agent, 5-azacytidine is very useful for epigenetic and cancer biology studies and for studying secondary metabolism in fungi. Full article

Ustilago esculenta is a dimorphic fungus that specifically infects Zizania latifolia, causing stem swelling and the formation of an edible fleshy stem known as jiaobai. The pathogenicity of U. esculenta is closely associated with the development of jiaobai and phenotypic differentiation. Msb2 acts as a key upstream sensor in the MAPK (mitogen-activated protein kinase) signaling pathway, playing critical roles in fungal hyphal growth, osmotic regulation, maintenance of cell wall integrity, temperature adaptation, and pathogenicity. In this study, we cloned the UeMsb2 gene from U. esculenta (GenBank No. MW768949). The open reading frame of UeMsb2 is 3015 bp in length, lacks introns, encodes a 1004-amino-acid protein with a conserved serine-rich domain, and is localized to the vacuole. Expression analysis revealed that UeMsb2 is inducibly expressed during both hyphal growth and infection processes. Deletion of UeMsb2 did not affect haploid morphology or growth rate in vitro but significantly impaired the strain’s mating ability, suppressed filamentous growth, slowed host infection progression, and downregulated the expression of b signaling pathway genes associated with pathogenicity. Notably, the deletion of UeMsb2 did not influence the in vitro growth of U. esculenta under hyperosmotic, thermal, or oxidative stress conditions. These findings underscore the critical role of UeMsb2 in regulating the pathogenicity of U. esculenta. This study provides insights into the interaction between U. esculenta and Z. latifolia, particularly the mechanisms that drive host stem swelling. Full article

Boletaceae, the largest and most diverse family of Boletales (Agaricomycetes and Basidiomycota), is both ecologically and economically important. Although many taxa have been described in China, the diversity of the family still remains incompletely understood. In the present study, Pseudophylloporus baishanzuensis gen. nov., sp. nov. and Rubroleccinum latisporus gen. nov., sp. nov. are proposed based on morphological and molecular phylogenetic analyses. These findings contribute to a deeper understanding of the diversity within the Boletaceae family. Full article

Nakaseomyces glabrata (Candida glabrata), the second most prevalent Candida pathogen globally, has emerged as a major clinical threat due to its ability to develop high-level azole resistance. In this study, two new 5,6-dihydrotetrazolo[1,5-c]quinazoline derivatives (c11 and c12) were synthesized and characterized using IR, LC-MS, ¹H, and ¹³C NMR spectra. Along with 13 previously reported analogues, these compounds underwent in vitro antifungal testing against clinical N. glabrata isolates using a serial dilution method (0.125–64 mg/L). Remarkably, compounds c5 and c1 exhibited potent antifungal activity, with minimum inhibitory concentrations of 0.37 μM and 0.47 μM, respectively—about a 20-fold improvement in μM concentration over standard drugs like amphotericin B, caspofungin, and micafungin. A detailed structure–activity relationship analysis revealed crucial molecular features enhancing antifungal potency. Extensive molecular docking studies across 18 protein targets explored potential binding pockets and affinities of the lead compounds. A robust 3D-QSAR model, incorporating molecular descriptors Mor26m and Mor29e, displayed good predictive ability for antifungal activity. In silico predictions indicated an absence of herbicidal effect, negligible environmental toxicity (to honeybees, avian species, and aquatic organisms), and mild human toxicity concerns for these compounds. This comprehensive approach aims to develop novel and effective antifungal compounds against the clinically relevant pathogen N. glabrata. Full article

Monascinol (Msol), an analog of monascin (MS) produced by Monascus pilosus, possesses potential anti-inflammatory properties. This study compares the effects of M. pilosus SWM-008 fermented red mold rice, which contains the functional components MS and Msol, on liver and kidney damage related to diabetic complications in rats. An animal model of liver and kidney injury was induced by an intraperitoneal injection of streptozotocin (STZ) at 65 mg/kg body weight combined with nicotinamide (NA) at 150 mg/kg body weight. Our findings indicate that Msol significantly reduces STZ-NA induced pro-inflammatory markers, including interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2) in both liver and kidney tissues. Significant improvements were noted in the histopathological assessments. Msol was more effective than MS in suppressing renal IL-1β and COX-2 expressions. In summary, the findings indicate that Msol shows potential as a novel therapeutic agent for treating liver and kidney injuries associated with diabetic complications. Full article

Batkoa is a genus of entomophthoralean fungi often associated with insect epizootics, particularly in phytophagous hemipterans. Encapsulation has become a promising strategy for improving the shelf life and sporulation of these fungi post-application. This study aims to (i) compare the virulence of the submerged propagules and primary conidia of Batkoa sp. ESALQ1199 against Dalbulus maidis; (ii) formulate submerged propagules in calcium alginate beads with co-formulants; (iii) assess the colony-forming units and sporulation of encapsulated beads dried with different kaolin concentrations (0%, 2%, 4%, 8% and 10%); (iv) determine the shelf life of dried bead formulations containing 10% kaolin, comparing washed and unwashed beads treated with a 4% sucrose solution; and (v) assess the sporulation capacity of beads with 10% kaolin, washed and unwashed with 4% sucrose solution, over time under humid conditions. Our results demonstrated that primary conidia and submerged propagules effectively killed 82.4% and 57.8% of adult corn leafhoppers, respectively. Co-formulants maintained viability above 80% in dried propagules, while control samples dropped to 45%, indicating the sensitivity of submerged propagules to the drying process. Encapsulated Batkoa sp. retained the same concentration of viable propagules per bead and the number of conidia produced (sporulation) for 30 days at 28 °C. The sporulation of fresh beads increased during the incubation period, plateauing after 27 days. This suggests that Batkoa sp. beads can produce primary conidia under humid field conditions, serving as a potential inoculum source for new infections. Full article

As environmental and health concerns increase, the trend toward sustainable agriculture is moving toward using biological agents. About 60% of all biological fungicides have Trichoderma species as the active ingredient, with T. harzianum as the most common species in these products. However, the name T. harzianum has often been used incorrectly in culture collections, databases, and scientific literature due to the division of the Harzianum clade (HC) into more than 95 cryptic species, with only one being named T. harzianum. In this study, 49 strains previously identified as T. harzianum in three surveys of Trichoderma species from soils in South and Central America were re-identified using phylogenetic analyses based on tef1α, rpb2, and ITS sequences obtained from GenBank. These were combined with the HC species from two other studies, which were identified based on the current taxonomy. Based on the results of the five surveys of the total 148 strains in HC, 11 species were identified. T. afroharzianum, T. lentiforme, and T. endophyticum, followed by T. azevedoi and T. harzianum, were the dominant species of the HC in South and Central America. This is the first report to identify dominant Trichoderma species within the HC in South and Central American soil based on multiple studies. These results will be useful in selecting strains within the clade for the formulation of biocontrol and biofertilizer products on the continent. Full article

Pythiosis, a rare and formidable infectious disease caused by Pythium insidiosum, is characterized by profound uncertainties in achieving definitive diagnoses, suboptimal outcomes, and an exceptionally high mortality rate. Here, we present a rare case of human spinal pythiosis in southern China. With advanced metagenomic sequencing technology, Pythium insidiosum was pinpointed as the causative pathogen. We discovered that the inoculation of either tissue fragments or homogenate yielded more successful results and enabled a moderate extension of the culture duration to 5–10 days through an exhaustive comparison of diverse inoculation and culture conditions for general clinical specimens. A pronounced genetic affinity of the isolated strain towards the Pythium insidiosum strain MCC 13 was detected after a comprehensive whole-genome sequencing analysis. Antifungal agents exhibited negligible sensitivity towards Pythium insidiosum in an antimicrobial susceptibility test. Conversely, antibacterial agents such as oxazolidinones, tetracyclines, macrolides, and amphenicols demonstrated varying degrees of sensitivity, albeit with most of their minimum inhibitory concentrations (MICs) substantially surpassing the safe concentration ranges for effective clinical treatment. Notably, tigecycline stood out as a promising candidate, exhibiting favorable therapeutic effects at moderate concentrations, making it a potential drug of choice for the control of pythiosis. A combined susceptibility test suggested that combinations of tetracyclines with macrolides, oxazolidinones, and amphenicols exhibited synergistic antibacterial effects, with the combination of doxycycline and trimethoprim–sulfamethoxazole (TMP-SMX) in particular playing a pivotal role. To our surprise, the MICs of iron chelators, specifically deferiprone and deferoxamine, against the strain were exceedingly low, which led to the speculation that exogenous iron chelators may have competitively inhibited the iron-chelating enzymes of the strain. The research derived from this single, rare case has certain limitations, but considering that there are currently no reports of invasive infections of deep organs in humans caused by Pythium insidiosum, the above findings can offer novel insights into the treatment of invasive pythiosis. Combination therapy based on tetracyclines, especially tigecycline, the use of TMP-SMX, and the adjunctive use of iron chelators, represent promising approaches to tackle the clinical challenges in the treatment of invasive pythiosis. However, further studies, including similar cases of spinal pythiosis and in vivo trials, are still needed to validate them. In addition, while paying attention to the therapeutic potentials of the above plans, we should also closely monitor the risks and side effects that may arise from excessive MICs or the expanded use of related drugs during the treatment process. Full article

The global rise in population has led to an increased demand for food production, necessitating the adoption of sustainable agricultural practices. Traditional methods often rely on synthetic chemicals that negatively impact both human health and the environment. This study aimed to screen soil fungal strains for plant-growth-promoting traits, specifically focusing on their ability to solubilize phosphates, produce indole-3-acetic acid (IAA), and synthesize siderophores. Fungal strains were identified using rDNA sequencing of the ITS regions, and their growth-promoting abilities were assessed in vitro. Aspergillus flavus JKJ7, Talaromyces purpureogenus JKJ12, and Trichoderma koningiopsis JKJ18 exhibited varying degrees of phosphate solubilization, with T. purpureogenus JKJ12 solubilizing the highest amount of tricalcium phosphate (TCP), while A. flavus JKJ7 was the most effective in solubilizing phytic acid calcium salt (PCS). In terms of IAA production, A. flavus JKJ7 produced the highest auxin concentration (68.51 mg/L), followed by T. koningiopsis JKJ18 and T. purpureogenus JKJ12. Additionally, A. flavus JKJ7 produced the highest amount of siderophores (83.7%), indicating its potential for improving iron uptake in plants. Principal Component Analysis (PCA) revealed distinct functional capabilities among the strains, particularly in phosphate solubilization and IAA production, suggesting their complementary use in consortium formulations. These results indicate that these fungal strains possess significant plant-growth-promoting traits and could be used as bioinoculants for sustainable agriculture, either as single strains or in combination Full article

The present study reports the ability of a fungal isolate Aspergillus ochraceus DY1, obtained from rotten wood, to degrade alkali lignin (AL) and lignocelluloses in an efficient manner. The efficiency of degradation was monitored by measuring the percentage of decolorization and utilizing GC-MS for identifying degradation products at different time intervals (10, 20, 30, and 40 days). The optimal degradation of alkali lignin (AL) was achieved at 0.01% concentration, 25 °C, and pH 7, resulting in 63.64% degradation after 40 days of incubation. A GC-MS analysis revealed significant degradation products, including n-hexadecanoic acid, octadecane, butylated hydroxytoluene, 2,6,11-trimethyl-dodecane, dibutyl phthalate, oleic acid, 3,5-dimethoxy-phenol acetate, and 2-(phenylmethylene)- cyclohexanone. Structural changes in AL were confirmed through HSQC 2D NMR and size-exclusion chromatography, indicating depolymerization and reduced molecular weight. Furthermore, A. ochraceus DY1 demonstrated substantial biomass loss in corn stover (62.5%) and sugarcane bagasse (50%) after 7 days of solid-state fermentation. Surface morphological depletion was observed in the bio-treated corn stover through SEM and confocal microscopy, which was not seen in the untreated one. These findings underscore the potential of A. ochraceus DY1 for efficient lignin degradation, with promising applications in biofuel production, waste management in the paper and pulp industry, and the synthesis of value-added bioproducts. Full article

In this paper, we present a novel class of hybrid polyketides, tenuazamines A–H (1–8), which exhibit a unique tautomeric equilibrium from Alternaria alternata FL7. The elucidation of the structures was achieved through a diverse combination of NMR, HR-ESIMS, and ECD methods, with a focus on extensive spectroscopic data analysis. Notably, compounds 1, 4, 8–9 exhibited potent toxic effects on the growth of Arabidopsis thaliana. This research expands the structural diversity of tenuazonic acid compounds derived from endophytic fungi and provides potential hit compounds for the development of herbicides. Full article

In the industrial production of Lentinula edodes and Pleurotus eryngii, slow growth of the mother seed and insufficient hyphal vitality can significantly affect the cultivation process. To shorten the growth period on traditional PDA medium, two strains of L. edodes and P. eryngii were cultured with different proportions of P. tuber-regium and Wolfiporia hoelen sclerotium powders added into the medium to investigate the effect on the mycelial growth. Compared to the PDA, the addition of sclerotia powder significantly enhanced the growth of mycelia, with an optimal addition ratio of 2%. Transcriptome sequencing was performed after culturing L. edodes and P. eryngii on PDA, PDA with 2% P. tuber-regium sclerotium powder, and PDA with 2% W. hoelen sclerotium powder. GO enrichment analysis of the differentially expressed genes (DEGs) of L. edodes and P. eryngii strains cultured in the sclerotia powder media showed significant changes in oxidoreductase and glucosidase activities. Changes were observed in KEGG annotation for carbohydrate metabolism, glycolysis, pyruvate metabolism, and other energy metabolic pathways. Moreover, carbohydrate-active enzyme (CAZyme) family genes were predominantly upregulated. The increase in the activity of CAZyme and oxidoreductases promotes the degradation of nutrients in the sclerotia into small-molecule substances, which explains why the sclerotia powder culture medium promotes mycelial growth. Full article

The complex structure of the plant cell wall makes it difficult to use the biomass produced by biosynthesis. For this reason, the search for new strains of microorganisms capable of efficiently degrading fiber is a topic of interest. For these reasons, the present study aimed to evaluate both the microbiological and enzymatic characteristics of the fungus Curvularia kusanoi L7strain. For this, its growth in different culture media was evaluated. Wheat straw mineralization was evaluated by gas chromatography assisted by infrared spectroscopy. The production of endo- and exoglucanase, laccase, and peroxidase enzymes in submerged solid fermentation of wheat and sugarcane bagasse were characterized. The strain efficiently mineralized raw wheat straw, showing a significant decrease in signals associated with cellulose, hemicellulose, and lignin in the infrared spectra. High enzyme productions were achieved in submerged solid fermentation of both substrates, highlighting the high production of endoglucanases in sugarcane bagasse (2.87 IU/mL) and laccases in wheat (1.64 IU/mL). It is concluded that C. kusanoi L7 is an ascomycete with a versatile enzyme production that allows it to exhaustively degrade complex fibers such as raw wheat straw and sugar cane bagasse, making it a microorganism with great potential in the bioconversion of plant biomass. Full article

Citrus spp. represent an economically important fruit tree crop worldwide. However, molecular mechanisms underlying the interaction between citrus and the Colletotrichum gloeosporioides remain largely unexplored. In this study, we analyzed the physiological and transcriptomic changes in Citrus sinensis at different stages of incubation with C. gloeosporioides. The results indicated that C. gloeosporioides infection rapidly triggered necrosis in the epicarp of C. sinensis fruits, decreased the total flavonoid contents, and suppressed the activity of catalase, peroxidase, and superoxide dismutase enzymes. Upon inoculation with C. gloeosporioides, there were 4600 differentially expressed genes (DEGs) with 1754 down-regulated and 2846 up-regulated after six hours, while there were only 580 DEGs with 185 down-regulated and 395 up-regulated between six and twelve-hours post-inoculation. Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that the DEGs, which exhibited consistent up-regulation, were associated with metabolic processes and stress responses. Through Weighted Gene Co-Expression Network Analysis, 11 key genes have been identified that could potentially play a role in the transcriptional regulation of this process, including the transcription factor bHLH189. Furthermore, the infection of C. gloeosporioides had a notable effect on both the flavonoid metabolism and the metabolic pathways related to reactive oxygen species. Our findings help to understand the interaction between citrus and C. gloeosporioides and unveil how new insights into how C. gloeosporioides circumvents citrus defense mechanisms. Full article

Fusarium oxysporum, the pathogen responsible for apple replant disease (ARD), is seriously threatening the apple industry globally. We investigated the antagonistic properties of Trichoderma strains against F. oxysporum HS2, aiming to find a biological control solution to minimize the dependence on chemical pesticides. Two of the thirty-one Trichoderma strains assessed through plate confrontation assays, L7 (Trichoderma atroviride) and M19 (T. longibrachiatum), markedly inhibited = F. oxysporum, with inhibition rates of 86.02% and 86.72%, respectively. Applying 1 × 10⁶ spores/mL suspensions of these strains notably increased the disease resistance in embryonic mung bean roots. Strains L7 and M19 substantially protected Malus robusta Rehd apple rootstock from ARD; the plant height, stem diameter, leaf number, chlorophyll content, and defense enzyme activity were higher in the treated plants than in the controls in both greenhouse and field trials. The results of fluorescent labeling confirmed the effective colonization of these strains of the root soil, with the number of spores stabilizing over time. At 56 days after inoculation, the M19 and L7 spore counts in various soils confirmed their persistence. These results underscore the biocontrol potential of L7 and M19 against HS2, offering valuable insights into developing sustainable ARD management practices. Full article

Diaporthe (anamorph: Phomopsis) species are endophytes or fungal pathogens for many different plant species. Soybean (Glycine max) can be infected by many different Diaporthe species; among them, D. caulivora and D. longicolla are responsible for the most significant damages. Diaporthe goulteri is a species that was only recently described and has so far been found on sunflower (Helianthus annuus) in Australia and an unknown host in Thailand. Here, we report isolation of D. goulteri from soybean in southern Germany, molecular species identification, and additional morphological description. We also show that D. goulteri can infect soybean and describe the symptoms we observed, both on the plant where the isolate came from and following artificial inoculation. Full article