Parasitic microorganisms play critical roles in shaping aquatic ecosystems, yet many lineages, such as those within the phylum Rozellomycota, remain poorly understood. Here, we describe a new rozellid isolate from the Gulf of Alaska. Phylogenomic analysis based on 238 genes confirms its placement within Rozellomycota and its distinctness from currently described taxa. We identified amplicon sequence variants (ASVs) from the metaPR2 database to recover its geographic distribution. Our isolate is an endoparasite of the diatom Thalassiosira, a primary producer in marine ecosystems that plays a critical role in global carbon and nutrient cycling. Phylogenetic and ecological evidence supports the establishment of a new genus within Rozellomycota, Rozellomyces. Our findings provide new insights into the diversity, distribution, and ecological roles of Rozellomycota, highlighting the need for further research on these parasites in marine ecosystems.
Chanterelles (genus Cantharellus) are ectomycorrhizal fungi associated with a broad host range of trees. We explored Cantharellus diversity in mixed oak forests across 12 counties in Virginia and constructed a multilocus phylogeny including large ribosomal subunit (28S), transcription elongation factor 1-alpha (tef1), and RNA polymerase II (rpb2) sequences from all known temperate species of Cantharellus. Habitat and morphological attributes, including spore size, shape, and color, were compared with described species. In total, 104 sequences from 31 specimen vouchers were generated and 11 taxa identified, including one new species, C. sabuletorum from sandy Quercus-Pinus forests of Chesapeake Bay and north-central Florida. This study also provides evidence of genetic and color variation within C. cinnabarinus and expands the known distribution of C. altipes, C. appalachiensis, C. flavolateritius, C. lateritius, C. lewisii, C. minor, C. tenuithrix complex, C. vicinus, and C. velutinus in the eastern United States.
During a survey of fungi associated with Cyperaceae plants in northern and northwestern Iran, three previously undescribed species belonging to Alternaria section Nimbya were identified and characterized. These new species, namely, Alternaria azarbaijanica, A. caspica, and A. eleocharidis, spp. nov. were examined using a combination of morphological traits, cultural features, and molecular data. Remarkably, all three species produced both sexual and asexual morphs under laboratory conditions, providing rare insights into reproductive modes within Alternaria, where sexual morphs are rarely observed. Phylogenetic analyses based on five gene regions (ITS-rDNA, GAPDH, TEF1, RPB2, and Alt a 1) clarified their evolutionary relationships and supported species delimitation. Phylogenetic trees constructed using maximum likelihood, maximum parsimony, and Bayesian inference consistently resolved each species as a distinct monophyletic lineage within Alternaria section Nimbya. These findings reveal previously unrecognized Alternaria diversity on Cyperaceae hosts and underscore the value of combining morphological observations with multilocus phylogenetic approaches to resolve taxonomic complexities in Alternaria.
Several species of the genus Gyromitra-commonly known as "false morels"-are traditionally consumed in different parts of the world, despite their potential toxicity due to the presence of monomethylhydrazine, a volatile compound. In some taxa, monomethylhydrazine content has been linked to environmental factors such as elevation, potentially influencing toxicity levels. In southern South America, ethnomycological records indicate that Gyromitra species are collected and consumed by indigenous communities. However, their taxonomy and toxicological profile remain poorly understood. In this study, we examined the phylogenetic identity and hydrazine content of Gyromitra specimens collected across a Patagonian elevation gradient. Molecular analyses based on nuclear internal transcribed spacer, large subunit, and elongation factor-1 alpha sequences confirmed the identity of all specimens as G. antarctica. Hydrazine content was quantified in 82 fresh samples collected between 300 and 800 m above sea level, revealing a significant negative correlation between elevation and toxin concentration (ρ = -0.79, P < 0.001). Two boiling treatments -10 min without water exchange, and 2 × 5 min with water exchange-reduced hydrazine levels by 97% and 94%, respectively. However, residual toxins were detected in the boiling water of both treatments. These findings provide new insights into the taxonomy and elevation-dependent toxicity of Gyromitra in the Southern Hemisphere. They also underscore the risks associated with the consumption of wild false morels and highlight the importance of informed and adequate culinary practices to reduce toxicity.
Native to South America, moth plant (Araujia hortorum, Apocynaceae) is an invasive vine that threatens natural ecosystems and agriculture in many parts of the world. Biological control studies involving fungal pathogens have primarily focused on the rust Puccinia araujiae, but other aggressive pathogens exist that may show potential as complementary agents. In its native range in Argentina, plants were quite frequently observed with severe leaf and fruit damage caused by a fungal disease. The pathogen associated with this disease was isolated and identified as Septoria araujiae based on morphological analyses. Multilocus analyses allowed the first phylogenetic placement of this species within the genus. Koch's postulates were fulfilled through inoculation experiments, confirming S. araujiae as the causal agent. The pathogen exhibited a hemibiotrophic life cycle, with an extended asymptomatic phase followed by a necrotrophic stage that led to severe defoliation. Host specificity experiments revealed a narrow host range, with susceptibility largely confined to species within the subtribe Oxypetalinae. These findings contribute new insights into the diversity, ecology, and host interactions of Septoria species and highlight the potential of S. araujiae as a biological control agent for A. hortorum.
Mucormycosis is a group of diseases that is increasing in frequency. A common opportunistic human fungal pathogen in this group is Rhizopus microsporus, which is a globally distributed species present in soil-associated environments. A subset of isolates in this species host endobacteria that are hypothesized to influence fungal pathogenicity in both clinical and environmental settings. We have limited understanding of how clinically and environmentally derived isolates are related or how physiological attributes, including thermotolerance and endosymbiosis, are correlated with population structure. Traditional molecular barcodes used to assess intraspecific relationships, such as ribosomal DNA internal transcribed spacer (ITS-rDNA)-based markers, do not provide species-level resolution, necessitating analyses of whole genome data. In this study, we generated novel whole genome sequencing data for six R. microsporus isolates and combined these data with publicly available whole genome sequences of 46 R. microsporus isolates. We evaluated these sequences to understand the evolutionary relationships among clinical and environmental isolates using phylogenomic and single nucleotide polymorphism (SNP)-based population genomics methods. We further studied their relationships by quantifying and comparing potential physiological differences and endosymbiont presence in a subset of 16 isolates with live cultures. We found that clinical isolates that originate from environmental settings contain higher molecular diversity than subpopulations isolated from clinical settings. We observed that environmental isolates grow faster than clinical isolates at temperatures between 22 and 37 C and that 7 of 16 (44%) contain endobacteria in the genus Mycetohabitans (Burkholderiales). Lastly, we observed that genome assembly size in R. microsporus is variable and that long-read sequencing technologies greatly enhance our ability to investigate the underlying genomic features. Our study provides a valuable backdrop for probing the basic biology and applied biomedical importance of Rhizopus and related fungi that cause mucormycosis.
A rarely collected rose-pink-colored Hericium americanum has now been documented with in situ images obtained by 11 different field naturalists in the northeastern United States and eastern Canada since 2018. These mushroom enthusiasts responded to a request for images and specimens of a rarely documented rose-pink-colored tooth fungus discussed in the comments section of a description of Hericium americanum and H. coralloides in Mushrooms of the Northeastern United States and Eastern Canada. Five of those finds were collected, preserved by drying, and sent to the authors for analysis. This strikingly colored tooth fungus is confirmed as a variant of H. americanum using morphological and molecular data (nuc rDNA ITS1-5.8S-ITS2 and partial nuc 28S rDNA D1-D6 regions) and proposed here as a new variety.
Candida spp. is an important genus associated with superficial and invasive diseases, especially in immunosuppressed patients. Although C. albicans is the most common species related to serious infections, non-albicans species have also emerged with high rates of antifungal resistance. Drug repositioning is a great alternative to reduce and control fungal resistance and infections. Paroxetine (PRX) and fluoxetine (FLX), both selective serotonin reuptake inhibitors antidepressants, are promising drugs with antifungal and antibacterial activities according to the literature, but studies exploring their mechanism of action and usage in combination with other antifungal drugs are scarce. Therefore, we evaluated the in vitro activity of PRX and FLX against Candida spp. The minimum inhibitory concentrations (MICs) were determined for PRX, FLX, and for the antifungals fluconazole, itraconazole, and amphotericin B (AMB), and checkerboard assay was performed to analyze the interactions between them. Furthermore, the possible mechanism of action was evaluated by flow cytometry, comet assay, measurement of protein oxidation, and determination of glutathione levels. The tested antidepressants had MIC values ranging from 8 to 128 μg/mL and mostly had synergistic interactions when combined with AMB. Additionally, their mechanisms of action can be related to the induction of severe oxidative stress that leads to apoptosis in fungal cells showing a synergistic effect when combined with AMB. Thus, the use of PRX and FLX may be an alternative to treat infections caused by resistant microorganisms, by enhanced effects at lower concentrations when combined with AMB, possibly reducing the risk of toxicity of both drugs.
Filamentous fungi produce secondary metabolites with multiple biochemical activities. For wood-decaying fungi of Basidiomycota, some of these compounds may act as redox-active mediators involved in biodegradation of lignocelluloses and biopolymers. Our aim was to identify natural aromatic compounds produced by white rot fungi of the genus Phlebia (Meruliaceae, Polyporales, Agaricomycetes), which comprises efficient decomposers of wood, wastes, and xenobiotics. Naturally produced aryl compounds were obtained by cultivating the fungi on a defined low-nitrogen liquid medium with glucose as carbon source. Culture supernatants were extracted and analyzed with UPLC-MS (ultra-performance liquid chromatography-mass spectrometry) and NMR (nuclear magnetic resonance). Enzyme assays, cultivation with 15N isotope-labeled nitrogen supplement, and aryl compound-feeding experiments were performed to assess biosynthesis mechanisms. Together with the well-known secondary metabolite veratryl alcohol and its enzymatic oxidation product veratraldehyde, we identified two nitroaryl derivatives, 6-nitroveratryl alcohol and 4-nitroveratrole, accumulating in culture supernatants of Phlebia spp. Cultivation of P. radiata isolate 2776 with NH4NO3 caused higher product yield of the nitroaryl compounds than 15NH4Cl supplementation, suggesting a role of nitrate ions in formation of nitroaryl products. With 15N-labeled supplementation, however, incorporation of nitrogen also from ammonium ions was observed. Although lignin peroxidase (LiP) enzyme activities correlated with appearance of nitroaryl compounds, their formation from veratryl alcohol by LiP was not accomplished in vitro in reaction mixtures with extracellular supernatants. In compound-feeding experiments, additional glycosylated derivative of 6-nitroveratryl alcohol was detected in P. radiata cultures, and nitroguaiacol was formed from nitroveratrole. These results indicate multiple pathways including both intra- and extracellular metabolism in biosynthesis and bioconversion of monoaromatic aryl compounds and their derivatives in fungi of Phlebia.
Four new species of the genus Phaeocollybia (Hymenogastraceae, Agaricales) from Yunnan Province, southwestern China, namely, P. ochrilata, P. conicogregaria, P. profundirhizoidea, and P. purpureorosea, are described and illustrated based on morphological data and multilocus phylogenetic analyses from DNA sequences of the internal transcribed spacer (ITS) and the second largest subunit of RNA polymerase II (RPB2). Our phylogenetic analyses revealed that the four new species belong to P. subgen. Phaeocollybia. Color photos of fresh basidiomata, line drawings of microscopic features, and their comparisons with allied taxa are presented.
Bidirectional solid fermentation can augment the therapeutic efficacy of Chinese herbal medicines by increasing their bioactive constituents. Chinese herbal medicines demonstrate specific antifungal properties. The potential of bidirectional solid fermentation to augment the antifungal efficacy of Chinese herbal treatments against plant-pathogenic fungi remains unexamined. This study employed bidirectional solid fermentation utilizing Irpex lacteus and eight traditional Chinese herbal medicines to investigate alterations in antifungal efficacy. The findings indicated that I. lacteus had comparatively fast development on the majority of Chinese herbal medicine substrates. Bidirectional solid fermentation markedly improved antifungal efficacy across the majority of substrates. The ethanol extract of Origanum vulgare, fermented for 10 d, exhibited an inhibition rate against most plant-pathogenic fungi equivalent to that of carbendazim at the same dose. The correlation analysis indicated a favorable association between total terpenoid concentration and antifungal efficacy. The metabolomic investigation indicated that, relative to the unfermented control, the metabolites considerably elevated in Origanum vulgare after 10 d of fermentation were primarily terpenoids, including pseudolaric acid B and prednisolone acetate, whereas the significantly decreased metabolites were primarily shikimic acid and phenylpropanoids, such as salvianolic acid C and icariside I. The KEGG (Kyoto Encyclopedia of Genes and Genomes)  pathway enrichment analyses revealed that the most significantly enriched pathway was tyrosine metabolism. These findings will help facilitate the creation of prospective biocontrol agents, therefore offering sustainable alternatives for crop disease management.
Fire is a common disturbance that structures terrestrial ecosystems. Since climate change models predict increases in fire frequency, it is important to study how changes in fire regime influence plant fuel-related above- and belowground ecosystem components. Due to their role in plant fuel production, arbuscular mycorrhizal (AM) fungal spore communities and symbioses with plants are invaluable for understanding how changes in fire regime influence belowground communities and alter fuel-related above- and belowground processes such as plant growth. With a greenhouse experiment, we tested how variation in fire frequency and history influenced AM fungal community composition, traits, and their interactions with host plants by manipulating fire regimes over three successive generations of AM fungi and Rudbeckia hirta plants. We found that fire frequency effects on spore traits such as pigmentation and sporulation mediated changes in AM fungal spore communities, but these effects took time to develop and were associated with reduced plant growth. This demonstrates that increases in fire frequency can alter the fire-fuel feedbacks that underlie pyrophilic ecosystems.
A new species, Vaginatispora bharatensis, is reported from the forest area of Pushpagiri Wildlife Sanctuary, Karnataka, India, based on morphological and molecular data (28S, 18S, ITS [internal transcribed space], tef1-α [translation elongation factor 1-alpha], rpb2 [RNA polymerase II second largest subunit], and β-tub [beta-tubulin] sequences). V. bharatensis is the first anamorphic report of the genus Vaginatispora based on conidial form collected from the wild. The species is introduced in this paper as a novel species, with comprehensive description, illustration, and multigene phylogenetic analysis.
Leaf samples displaying necrotic lesions were collected from Archidendron lucyi (Fabaceae), Litsea pungens (Lauraceae), and Malus hupehensis (Rosaceae) in China. Fungal strains isolated from these symptomatic tissues were assignable to Colletotrichum. Species delimitation relied on multilocus phylogeny, with colony and morphological characters documented for comparison and formal description. Three new species were identified and described, namely, Colletotrichum archidendri in the dracaenophilum complex and C. litseae and C. brunni in the gloeosporioides complex. Detailed morphological descriptions and illustrations are provided for each species. This study also expands the known host range of Colletotrichum and contributes to the understanding of species diversity within the genus.
Rhizopogon (Boletales) is an ectomycorrhizal (ECM) fungal genus that forms specific symbiotic associations with host trees within the family Pinaceae, playing a crucial role in seedling growth and establishment. Despite its ecological importance, the species diversity and phylogenetic relationships of Rhizopogon in East Asia remain poorly understood. Here, we investigate the diversity, phylogeny, and host specificity of Japanese Rhizopogon species. We conducted phylogenetic analyses of 106 basidiomata and three ECM root tip samples collected across Japan using three loci: the internal transcribed spacer (ITS), large subunit ribosomal RNA (LSU), and RNA polymerase II subunit B (RPB2). Phylogenetic analyses revealed at least 16 distinct lineages, including one only detected from a single root tip collected in Japan. Among the lineages with basidiomata, five corresponded to previously described species (R. alpinus, R. boninensis, R. lucidus, R. togasawarius, and R. yakushimensis). Seven other lineages, which did not cluster with any previously recognized species, are described here as new species and detailed morphological characteristics are provided: R. citrinus, R. filivolubilis, R. flavoroseolus, R. japonicus, R. melliodorus, R. margaritaceus, and R. politus. Two other lineages are new to Japan: R. pseudoroseolus and R. evadens. Another lineage, previously regarded as the Japanese "Shouro," was reidentified as R. graveolens based on morphological and molecular evidence. This study is the first comprehensive taxonomic assessment of Rhizopogon in East Asia.
Manganese (Mn) plays a vital role in soil chemistry, plant nutrition, and contaminant cycling, with certain microorganisms capable of transforming soluble Mn(II) into insoluble biogenic manganese oxides. Among these microorganisms, filamentous fungi are especially effective Mn oxidizers, often surpassing bacteria under challenging environmental conditions. The Acremonium-like fungi, historically recognized for their ecological versatility and production of bioactive metabolites, are now known to be highly polyphyletic, with species spanning multiple genera within the family Bionectriaceae. Despite their diversity, the ecological functions of these fungi remain poorly understood, and Mn-oxidizing activity has not previously been reported from this family. In this study, we surveyed saline-alkali soils in Dongying and Binzhou, Shandong Province, China. Seven Acremonium-like fungal isolates from halophytic rhizospheres were recovered from Dongying, but not from Binzhou. Multilocus phylogenetic analyses using ITS (internal transcribed spacer), 28S (28S ribosomal large subunit), tef1-α (elongation factor 1-alpha), and rpb2 (second largest subunit of RNA polymerase II), along with detailed morphological characterization, demonstrated that these isolates represent three previously undescribed species within the genera Acremonium, Protocreopsis, and Verruciconidia. Remarkably, all isolates exhibited Mn(II)-oxidizing activity, representing the first report of this trait in Bionectriaceae. These findings broaden the taxonomic and ecological understanding of Acremonium-like fungi and suggest their potential role in manganese cycling in extreme soils. Their tolerance to environmental stress, combined with Mn-oxidizing capabilities, indicates potential applications in bioremediation, soil health enhancement, and biotechnology. By uncovering novel extremophilic fungi with functional significance, this study provides insights into microbial adaptation in harsh environments and identifies promising resources for the sustainable management of saline-alkali soils.
Bird's nest fungi (Nidula candida) growing along ~18-year-old cedar fences in Pacific Spirit Regional Park, Vancouver, British Columbia, Canada, produce abundant, persistent peridia containing basidiospore-bearing, egg-like peridioles. To reconstruct the initial mode of reproduction of the populations, 37 peridia were collected following a geometric sampling design, with 8-10 peridia collected 6-222 cm apart from each of four fence segments. We cultured dikaryotic mycelium from one whole peridiole from each peridium and 105 monokaryons from basidiospores from 8 peridioles. We then tested mycelial compatibility by confronting pairs of dikaryons and sexual compatibility by mating the monokaryons from basidiospores. The resulting genetic patterns allowed us to map genetic individuals back to their fence segments. The dikaryotic mycelia that grew from whole peridioles fell into six mycelial compatibility groups, with one or two groups per 3-7 m fence segment. Consistent with an outcrossing origin, four different mycelial compatibility groups had different mating types. The largest compatibility group covered over 6 m of fence, producing 114 peridia and ~4.2 billion spores. One compatibility group was present at two fence sites ~40 m apart, suggesting asexual dispersal. This can potentially be explained by somatic growth from the walls of dispersed peridioles. Dikaryons generated by mating sibling monokaryons isolated from basidiospores from the same peridiole showed mycelial incompatibility in 86% of pairings. Thus, the compatible dikaryotic mycelia emerging from whole peridioles likely represent clones of parental mycelium rather than recombinant meiotic hyphae from basidiospores. Asexual reproduction from dispersed fruit body tissue is unusual in Agaricales, but in N. candida fence-hopping of peridioles splashed from peridia and germinating as clonal, parental-type dikaryotic mycelia may have contributed to expansion of a genet along the fence.
During scientific expeditions across the Qinghai-Tibetan Plateau, a group of Buellia species were frequently collected from alpine arid regions. These were characterized by having whitish chalky thalli, a surface covered with thick coarse pruina, a reddish-brown hypothecium, and the presence of xanthones. Detailed observations were made of specimen morphology and anatomy. Phylogenetic analysis was conducted based on four loci: the internal transcribed spacer of the rDNA (ITS), partial large subunit nuc rDNA region (28S), RNA polymerase II second largest subunit gene (rpb2), and β-tubulin gene (tubb). Three species, which formed a new distinct lineage within Buellia s.l. were confirmed as new to science: Buellia plana, B. elevata, and B. tibetana. This lineage is here referred to as the pruinocalcarea-group because of a species previously described that belongs to this group: B. pruinocalcarea. Species included in this group are closely related to Tetramelas; the group also has affinities to the epigaea-group and subalbula-group. Detailed descriptions, photographs of the new species, and a key to the species are provided.
Mexican dry ecosystems, mainly tropical dry forests, harbor a vast and largely undiscovered fungal diversity. The stalked puffballs of Tulostoma (Basidiomycota: Agaricales) are highly cryptic, necessitating detailed and expert examination to accurately distinguish the species. A revision of the MEXU national fungarium and recent sampled specimens revealed fruiting bodies that did not match any known species. This led us to propose T. parvirufula and T. chamelensis as new species. Six collections were morphologically characterized using two microscopy techniques: light and scanning electron microscopy. DNA was extracted, the nuc rDNA internal transcribed spacer region ITS15.8S-ITS2 (ITS barcode) and D1-D2 domains of the nuc 28S rDNA were amplified and sequenced. Phylogenetic analyses were conducted using maximum likelihood and Bayesian inference methods, incorporating sequences from previous studies. Tulostoma chamelensis is distinguished by its medium-sized spore sac, a hyphal exoperidium that persists at the base, a tubular ostiole, and verrucose to subreticulate basidiospores. Tulostoma parvirufula is characterized by minute spore sacs, a tubular ostiole, a hyphal exoperidium, a reddish-brown endoperidium, and spiny basidiospores. Phylogenetic analyses place both species in a sister clade to clade 11, alongside other taxa with tubular ostioles and coarsely ornamented basidiospores, further expanding our understanding of the Tulostoma genus and its diversity in dry ecosystems.