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Phyllosticta citricarpa is an important citrus-pathogen and a quarantine organism in the European Union. Its recently described relative, P. paracitricarpa, is very closely related and not listed as a quarantine organism. P. paracitricarpa is very difficult to distinguish from P. citricarpa, since its morphological features overlap and the barcoding gene sequences that were originally used to delimit them as distinct species have a low number of species-specific polymorphisms that have subsequently been shown to overlap between the two clades. Therefore, we performed extensive genomic analyses to determine whether the genetic variation between P. citricarpa and P. paracitricarpa strains should be considered to represent infraspecific variation within P. citricarpa, or whether it is indicative of distinct species. Using a phylogenomic analysis with 3,000 single copy ortholog genes and whole-genome comparisons, we determined that the variation between P. citricarpa and P. paracitricarpa can be considered as infraspecies variation within P. citricarpa. We also determined the level of variation in mitochondrial assemblies of several Phyllosticta species and concluded there are only minimal differences between the assemblies of P. citricarpa and P. paracitricarpa. Thus, using several orthogonal approaches, we here demonstrate that variation within the nuclear and mitochondrial genomes of other Phyllosticta species is larger than variation between genomes obtained from P. citricarpa and P. paracitricarpa strains. Thus, P. citricarpa and P. paracitricarpa should be considered as conspecific.

Effector secretion is crucial for root endophytes to establish and protect their ecological niche. We used time-resolved transcriptomics to monitor effector gene expression dynamics in two closely related Sebacinales, Serendipita indica and Serendipita vermifera, during symbiosis with three plant species, competition with the phytopathogenic fungus Bipolaris sorokiniana, and cooperation with root-associated bacteria. We observed increased effector gene expression in response to biotic interactions, particularly with plants, indicating their importance in host colonization. Some effectors responded to both plants and microbes, suggesting dual roles in intermicrobial competition and plant-microbe interactions. A subset of putative antimicrobial effectors, including a GH18-CBM5 chitinase, was induced exclusively by microbes. Functional analyses of this chitinase revealed its antimicrobial and plant-protective properties. We conclude that dynamic effector gene expression underpins the ability of Sebacinales to thrive in diverse ecological niches with a single fungal chitinase contributing substantially to niche defense.

Zymoseptoria tritici is the most economically significant fungal pathogen of wheat in Europe. However, despite the importance of this pathogen, the molecular interactions between pathogen and host during infection are not well understood. Herein, we describe the use of two libraries of cloned Z. tritici effectors that were screened to identify effector candidates with putative pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI)-suppressing activity. The effectors from each library were transiently expressed in Nicotiana benthamiana, and expressing leaves were treated with bacterial or fungal PAMPs to assess the effectors ability to suppress reactive oxygen species (ROS) production. From these screens, numerous effectors were identified with PTI-suppressing activity. In addition, some effectors were able to suppress cell death responses induced by other Z. tritici secreted proteins. We used structural prediction tools to predict the putative structures of all of the Z. tritici effectors and used these predictions to examine whether there was enrichment of specific structural signatures among the PTI-suppressing effectors. From among the libraries, multiple members of the killer protein-like 4 (KP4) and killer protein-like 6 (KP6) effector families were identified as PTI suppressors. This observation is intriguing, as these protein families were previously associated with antimicrobial activity rather than virulence or host manipulation. This data provides mechanistic insight into immune suppression by Z. tritici during infection and suggests that, similar to biotrophic pathogens, this fungus relies on a battery of secreted effectors to suppress host immunity during early phases of colonization.

Botryosphaeriaceae species are the major causal agents of walnut dieback worldwide, along with Diaporthe species. Botryosphaeria dothidea and Neofusicoccum parvum are the only two Botryosphaeriaceae species associated with this recently emergent disease in France, and little is known about their diversity, structure, origin and dispersion in French walnut orchards. A total of 381 isolates of both species were genetically typed using a sequence-based microsatellite genotyping (SSR-seq) method. This analysis revealed a low genetic diversity and a high clonality of these populations, in agreement with their clonal mode of reproduction. The genetic similarity among populations, regardless of the tissue type and the presence of symptoms, supports the hypothesis that these pathogens can move between fruits and twigs and display latent pathogen lifestyles. Contrasting genetic patterns between N. parvum populations from Californian and Spanish walnut orchards and the French ones suggested no conclusive evidence for pathogen transmission from infected materials. The high genetic similarity with French vineyards populations suggested instead putative transmission between these hosts, which was also observed with B. dothidea populations. Overall, this study provides critical insight into the epidemiology of two important pathogens involved in the emerging dieback of French walnut orchards, including their distribution, potential to mate, putative origin and disease pathways.

BACKGROUND: Sclerotinia spp. are generalist fungal pathogens, infecting over 700 plant hosts worldwide, including major crops. While host resistance is the most sustainable and cost-effective method for disease management, complete resistance to Sclerotinia diseases is rare. We recently identified soft basal stem as a potential susceptibility factor to Sclerotinia minor infection in lettuce (Lactuca sativa) under greenhouse conditions. RESULTS: Analysis of stem and root cell wall composition in five L. sativa and one L. serriola accessions with varying growth habits and S. minor resistance levels revealed strong association between hemicellulose constituents, lignin polymers, disease phenotypes, and basal stem mechanical strength. Accessions resistant to basal stem degradation consistently exhibited higher levels of syringyl, guaiacyl, and xylose, but lower levels of fucose in stems. These findings suggest that stem cell wall polymers recalcitrant to breakdown by lignocellulolytic enzymes may contribute to stem strength-mediated resistance against S. minor. CONCLUSIONS: The lignin content, particularly guaiacyl and syringyl, along with xylose could potentially serve as biomarkers for identifying more resistant lettuce accessions and breeding lines. Basal stem degradation by S. minor was influenced by localized microenvironment conditions around the stem base of the plants.

BACKGROUND: Populations of the plant pathogenic fungus Verticillium dahliae display a complex and rich genetic diversity, yet the existence of sexual reproduction in the fungus remains contested. As pivotal genes, MAT genes play a crucial role in regulating cell differentiation, morphological development, and mating of compatible cells. However, the functions of the two mating type genes in V. dahliae, VdMAT1-1-1, and VdMAT1-2-1, remain poorly understood. RESULTS: In this study, we confirmed that the MAT loci in V. dahliae are highly conserved, including both VdMAT1-1-1 and VdMAT1-2-1 which share high collinearity. The conserved core transcription factor encoded by the two MAT loci may facilitate the regulation of pheromone precursor and pheromone receptor genes by directly binding to their promoter regions. Additionally, peptide activity assays demonstrated that the signal peptide of the pheromone VdPpg1 possessed secretory activity, while VdPpg2, lacked a predicted signal peptide. Chemotactic growth assays revealed that V. dahliae senses and grows towards the pheromones FO-a and FO-α of Fusarium oxysporum, as well as towards VdPpg2 of V. dahliae, but not in response to VdPpg1. The findings herein also revealed that VdMAT1-1-1 and VdMAT1-2-1 regulate vegetative growth, carbon source utilization, and resistance to stressors in V. dahliae, while negatively regulating virulence. CONCLUSIONS: These findings underscore the potential roles of VdMAT1-1-1 and VdMAT1-2-1 in sexual reproduction and confirm their involvement in various asexual processes of V. dahliae, offering novel insights into the functions of mating type genes in this species.

Fungi use the accessory gene content of their pangenomes to adapt to their environments. While gene presence-absence variation contributes to shaping accessory gene reservoirs, the genomic contexts that shape these events remain unclear. Since pangenome studies are typically species-wide and do not analyze different populations separately, it is yet to be uncovered whether presence-absence variation patterns and mechanisms are consistent across populations. Fungal plant pathogens are useful models for studying presence-absence variation because they rely on it to adapt to their hosts, and members of a species often infect distinct hosts. We analyzed gene presence-absence variation in the blast fungus, Magnaporthe oryzae (syn. Pyricularia oryzae), and found that presence-absence variation genes involved in host-pathogen and microbe-microbe interactions may drive the adaptation of the fungus to its environment. We then analyzed genomic and epigenomic features of presence-absence variation and observed that proximity to transposable elements, gene GC content, gene length, expression level in the host, and histone H3K27me3 marks were different between presence-absence variation genes and conserved genes. We used these features to construct a model that was able to predict whether a gene is likely to experience presence-absence variation with high precision (86.06%) and recall (92.88%) in M. oryzae. Finally, we found that presence-absence variation genes in the rice and wheat pathotypes of M. oryzae differed in their number and their genomic context. Our results suggest that genomic and epigenomic features of gene presence-absence variation can be used to better understand and predict fungal pangenome evolution. We also show that substantial intra-species variation can exist in these features.

Autophagy in eukaryotes functions to maintain homeostasis by degradation and recycling of long-lived and unwanted cellular materials. Autophagy plays important roles in pathogenicity of various fungal pathogens, suggesting that autophagy is a novel target for development of antifungal compounds. Here, we describe bioluminescence resonance energy transfer (BRET)-based high-throughput screening (HTS) strategy to identify compounds that inhibit fungal ATG4 cysteine protease-mediated cleavage of ATG8 that is critical for autophagosome formation. We identified ebselen (EB) and its analogs ebselen oxide (EO) and 2-(4-methylphenyl)-1,2-benzisothiazol-3(2H)-one (PT) as inhibitors of fungal pathogens Botrytis cinerea and Magnaporthe oryzae ATG4-mediated ATG8 processing. The EB and its analogs inhibit spore germination, hyphal development, and appressorium formation in Ascomycota pathogens, B. cinerea, M. oryzae, Sclerotinia sclerotiorum and Monilinia fructicola. Treatment with EB and its analogs significantly reduced fungal pathogenicity. Our findings provide molecular insights to develop the next generation of antifungal compounds by targeting autophagy in important fungal pathogens.

Continuous cropping obstacle has been becoming the bottleneck for the stable development of morel cultivation. The allelopathic effect of soil allelochemicals may play an instrumental role in the morel soil sickness. In this study, the allelochemicals were identified by gas chromatography-mass spectrometry (GC-MS) combined with in vitro bioassay. A total of 61 chemical substances were identified through the GC-MS analysis of 12 replanting and control soil samples, comprising 10 phenolic acids, 36 acids, 3 aldehydes, etc. Among which, 15 compounds with values of variable importance for the projection (VIP) greater than 1 in the orthogonal partial least squares-discriminant analysis (OPLS-DA) were selected as the differential metabolites between soil samples of continuous cropping and control. The bioassay showed that 4-coumaric acid and vanillic acid exhibited inhibitory effect on mycelial growth of three cultivated Morchella mushrooms (M. sextelata, M. eximia and M. importuna) under soil native concentrations. Analysis of potential biosynthetic pathways of phenolic acids found that the 3 cultivable Morchella mushrooms are unable to synthesize phenolic acid allelochemicals. Therefore, although they were detected in trace amounts in static culture broth of M. sextelata, the two phenolic acids can only be defined as morel allelochemicals rather than autotoxins. Taken together, we found two morel allelochemicals that may derive from morel related microbes and plants, which will be helpful for further fundamental study and application in morel artificial cultivation. [ABSTRACT FROM AUTHOR]

This study advances our understanding of Ophiocordyceps, an extensively studied entomopathogenic fungus within the Ophiocordycipitaceae, particularly in Thailand. We introduce seven novel species associated with Coleoptera - O. albostroma, O. brunnea, O. capilliformis, O. kohchangensis, O. phitsanulokensis, O. pseudovariabilis, and O. ratchaburiensis. Remarkably, O. brunnea, O. kohchangensis, and O. ratchaburiensis exhibit ascomata on the subterminal region of the stromata, with the asexual form appearing at the apex of the stipe, reminiscent of O. brunneipunctata. In contrast, O. phitsanulokensis produces its ascomata in the upper region of the stipe. Shared traits include immersed perithecia and part-spores production. Ophiocordyceps albostroma and O. pseudovariabilis produce pseudo-immersed perithecia, with the former producing ascospores breaking into four part-spores, and the latter displaying 32 part-spores. Ophiocordyceps capilliformis is also introduced due to morphological distinctions from closely related species. Phylogenetic analyses based on multigene loci (LSU, TEF1, RPB1, RPB2) robustly confirm the placement of these new species within Ophiocordyceps. Additionally, we report a new record of O. clavata in Thailand. [ABSTRACT FROM AUTHOR]

A new species of Helicascus satunensis sp. nov. was collected on mature dead fruits of the Nypa palm in Satun Province, southern Thailand. Its morphological characteristics are similar to those of the genus Helicascus. Recently, a genus Helicascus with three species from marine habitats worldwide was studied. The morphology of this fungus was investigated and combined with multigene sequence analyzes of small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS) ribosomal DNA, translation elongation factor 1-alpha (TEF-1α) and RNA polymerase II (RPB2) genes. Morphologically, H. satunensis sp. nov. is characterized by semi-immersed, lenticular ascomata, multilocules, a bitunicate ascus and smooth, obovoid, dark brown ascospores that are one-septate and unequally two-celled. In addition, 3D visualization using synchrotron X-ray tomography was performed to investigate the interaction between fruiting body and substrata. Molecular phylogeny with multigene revealed that H. satunensis sp. nov. belongs to the family Morosphaeriaceae, order Pleosporales, class Dothideomycetes. Furthermore, H. satunensis sp. nov. forms a well-supported clade with Helicascus species described from marine habitats. Based on the unique morphological and molecular evidence, we propose this fungus, H. satunensis sp. nov., as a new species for Helicascus. [ABSTRACT FROM AUTHOR]

Little is known regarding the diversity patterns of Xylariaceae and Hypoxylaceae (Ascomycota) fungi taking part in the lignin decomposition of leaf litter from different tree species and under different climatic regions. The alpha and beta diversity of Xylariaceae and Hypoxylaceae fungi was investigated on bleached leaf litter from nine subtropical and cool temperate tree species in Japan. A total of 248 fungal isolates, obtained from 480 leaves from the nine tree species, were classified into 43 operational taxonomic units (OTUs) with a 97% similarity threshold and were assigned to nine genera of Xylariaceae and Hypoxylaceae. There was no overlap of fungal OTUs between subtropical and cool temperate trees. The mean number of fungal OTUs was generally higher in subtropical than cool temperate trees, whereas rarefaction curves depicting the numbers of OTU with respect to the number of leaves from which fungi were isolated were less steep in subtropical trees than in cool temperate trees, reflecting the dominance of major OTUs in the subtropical trees and indicating a higher species richness in cool temperate regions. Nonmetric multidimensional scaling showed general overlaps of fungal OTU compositions among tree species in the respective climatic regions, and one-way permutational multivariate analysis of variance indicated that the OTU composition was not significantly different between the tree species. These results suggest a wide host range and some geographic and climatic structures of distribution of these ligninolytic fungi.

BACKGROUND: Fungal plant pathogens have dynamic genomes that allow them to rapidly adapt to adverse conditions and overcome host resistance. One way by which this dynamic genome plasticity is expressed is through effector gene loss, which enables plant pathogens to overcome recognition by cognate resistance genes in the host. However, the exact nature of these loses remains elusive in many fungi. This includes the tomato pathogen Cladosporium fulvum, which is the first fungal plant pathogen from which avirulence (Avr) genes were ever cloned and in which loss of Avr genes is often reported as a means of overcoming recognition by cognate tomato Cf resistance genes. A recent near-complete reference genome assembly of C. fulvum isolate Race 5 revealed a compartmentalized genome architecture and the presence of an accessory chromosome, thereby creating a basis for studying genome plasticity in fungal plant pathogens and its impact on avirulence genes. RESULTS: Here, we obtained near-complete genome assemblies of four additional C. fulvum isolates. The genome assemblies had similar sizes (66.96 to 67.78 Mb), number of predicted genes (14,895 to 14,981), and estimated completeness (98.8 to 98.9%). Comparative analysis that included the genome of isolate Race 5 revealed high levels of synteny and colinearity, which extended to the density and distribution of repetitive elements and of repeat-induced point (RIP) mutations across homologous chromosomes. Nonetheless, structural variations, likely mediated by transposable elements and effecting the deletion of the avirulence genes Avr4E, Avr5, and Avr9, were also identified. The isolates further shared a core set of 13 chromosomes, but two accessory chromosomes were identified as well. Accessory chromosomes were significantly smaller in size, and one carried pseudogenized copies of two effector genes. Whole-genome alignments further revealed genomic islands of near-zero nucleotide diversity interspersed with islands of high nucleotide diversity that co-localized with repeat-rich regions. These regions were likely generated by RIP, which generally asymmetrically affected the genome of C. fulvum. CONCLUSIONS: Our results reveal new evolutionary aspects of the C. fulvum genome and provide new insights on the importance of genomic structural variations in overcoming host resistance in fungal plant pathogens.

Among molecular biologists, the group of fungi called Saccharomycotina is famous for its yeasts. These yeasts in turn are famous for what they have in common-genetic, biochemical, and cell-biological characteristics that serve as models for plants and animals. But behind the apparent homogeneity of Saccharomycotina species lie a wealth of differences. In this review, we discuss traits that vary across the Saccharomycotina subphylum. We describe cases of bright pigmentation; a zoo of cell shapes; metabolic specialties; and species with unique rules of gene regulation. We discuss the genetics of this diversity and why it matters, including insights into basic evolutionary principles with relevance across Eukarya.

Members of the family Trichomeriaceae, belonging to the Chaetothyriales order and the Ascomycota phylum, are known for their capability to inhabit hostile environments characterized by extreme temperatures, oligotrophic conditions, drought, or presence of toxic compounds. The genus Knufia encompasses many polyextremophilic species. In this report, the genomic and morphological features of the strain FJI-L2-BK-P2 presented, which was isolated from the Mars 2020 mission spacecraft assembly facility located at the Jet Propulsion Laboratory in Pasadena, California. The identification is based on sequence alignment for marker genes, multi-locus sequence analysis, and whole genome sequence phylogeny. The morphological features were studied using a diverse range of microscopic techniques (bright field, phase contrast, differential interference contrast and scanning electron microscopy). The phylogenetic marker genes of the strain FJI-L2-BK-P2 exhibited highest similarities with type strain of Knufia obscura (CBS 148926T) that was isolated from the gas tank of a car in Italy. To validate the species identity, whole genomes of both strains (FJI-L2-BK-P2 and CBS 148926T) were sequenced, annotated, and strain FJI-L2-BK-P2 was confirmed as K. obscura. The morphological analysis and description of the genomic characteristics of K. obscura FJI-L2-BK-P2 may contribute to refining the taxonomy of Knufia species. Key morphological features are reported in this K. obscura strain, resembling microsclerotia and chlamydospore-like propagules. These features known to be characteristic features in black fungi which could potentially facilitate their adaptation to harsh environments.

The import of plant-derived small sugars by sugar transporters (STs) has received increasing interest due to its important biological role and great industrial potential. STs are important targets of genetic engineering to improve fungal plant biomass conversion. Comparatively analysis of the genome-wide prevalence and transcriptomics of STs was performed in four filamentous fungi: Aspergillus niger, Aspergillus nidulans, Penicillium subrubescens and Trichoderma reesei. Using phylogenetic analysis and literature mining, their predicted STs were divided into ten subfamilies with putative sugar specificities assigned. In addition, transcriptome analysis revealed complex expression profiles among different STs subfamilies and fungal species, indicating a sophisticated transcriptome regulation and functional diversity of fungal STs. Several STs showed strong co-expression with other genes involved in sugar utilization, encoding CAZymes and sugar catabolic enzymes. This study provides new insights into the diversity of STs at the genomic/transcriptomic level, facilitating their biochemical characterization and metabolic engineering.

ImportanceInherent complexities in the composition of microbiomes can often preclude investigations of microbe-associated diseases. Instead of single organisms being associated with disease, community characteristics may be more relevant. Longitudinal microbiome studies of the same individual bats as pathogens arrive and infect a population are the ideal experiment but remain logistically challenging; therefore, investigations like our approach that are able to correlate invasive pathogens to alterations within a microbiome may be the next best alternative. The results of this study potentially suggest that microbiome-host interactions may determine the likelihood of infection. However, the contrasting relationship between Pd and the bacterial microbiomes of Myotis lucifugus and Perimyotis subflavus indicate that we are just beginning to understand how the bat microbiome interacts with a fungal invader such as Pd.

Fungal effectors play critical roles in manipulating plant immune responses and promoting colonization. Sphaerulina musiva is a heterothallic ascomycete fungus that causes Septoria leaf spot and stem canker disease in poplar (Populus spp.) plantations. This disease can result in premature defoliation, branch and stem breakage, increased mortality, and plantation failure. However, little is known about the interaction between S. musiva and poplar. Previous work predicted 142 candidate secreted effector proteins in S. musiva (SmCSEPs), 19 of which were selected for further functional characterization in this study. SmCSEP3 induced plant cell death in Nicotiana benthamiana, while 8 out of 19 tested SmCSEPs suppressed cell death. The signal peptides of these eight SmCSEPs exhibited secretory activity in a yeast signal sequence trap assay. Confocal microscopy revealed that four of these eight SmCSEPs target both the cytoplasm and the nucleus, whereas four predominantly localize to discrete punctate structures. Pathogen challenge assays in N. benthamiana demonstrated that the transient expression of six SmCSEPs promoted Fusarium proliferatum infection. The expression of these six SmCSEP genes were induced during infection. SmCSEP2, SmCSEP13, and SmCSEP25 suppressed chitin-triggered reactive oxygen species burst and callose deposition in N. benthamiana. The candidate secreted effector proteins of S. musiva target multiple compartments in the plant cell and modulate different pattern-triggered immunity pathways. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2023.

Acarospora socialis, the bright cobblestone lichen, is commonly found in southwestern North America. This charismatic yellow lichen is a species of key ecological significance as it is often a pioneer species in new environments. Despite their ecological importance virtually no research has been conducted on the genomics of A. socialis. To address this, we used long-read sequencing to generate the first high-quality draft genome of A. socialis. Lichen thallus tissue was collected from Pinkham Canyon in Joshua Tree National Park, California and deposited in the UC Riverside herbarium under accession #295874. The de novo assembly of the mycobiont partner of the lichen was generated from Pacific Biosciences HiFi long reads and Dovetail Omni-C chromatin capture data. After removing algal and bacterial contigs, the fungal genome was approximately 31.2 Mb consisting of 38 scaffolds with contig and scaffold N50 of 2.4 Mb. The BUSCO completeness score of the assembled genome was 97.5% using the Ascomycota gene set. Information on the genome of A. socialis is important for California conservation purposes given that this lichen is threatened in some places locally by wildfires due to climate change. This reference genome will be used for understanding the genetic diversity, population genomics, and comparative genomics of A. socialis species. Genomic resources for this species will support population and landscape genomics investigations, exploring the use of A. socialis as a bioindicator species for climate change, and in studies of adaptation by comparing populations that occur across aridity gradients in California.

A list of 20 rare in Ukraine species of macrofungi (Ascomycota and Basidiomycota) recorded in 2012–2023 in the Kamenisty protected area (Hutsulshchyna National Nature Park, Ivano-Frankivsk Region) is provided. Of them, 12 records are new for the Ukrainian Carpathians. Information about habitats, substrate preferences, ecological features and general distribution of the fungi is provided. Eight species (Clitocybe angustissima, Cortinarius praestans, C. prasinus, Discina fastigiata, Hygrophorus poetarum, Lactarius acerrimus, Leucopaxillus gentianeus and Tricholoma pardinum), which are red-listed in a number of European countries, are recommended to be included in the Red List of fungi of Ivano-Frankivsk Region.

Tuber magnatum Picco, the Italian white truffle mushroom recorded for the first time in Türkiye, is a rare and economically valuable mushroom. Samples were collected from Sakarya province during field studies in 2024. The samples were identified as T. magnatum according to their macro- and microscopic features. To make molecular confirmation of the species, the samples' ITS1 and ITS4 gene regions were analysed and registered in Genbank with the number PP239641. The sample showed 100% compatibility with other T. magnatum accessions in Genbank. The distributions of Tuber species in Türkiye were given, and their taxonomic features were compared.

A large number of species in the genus Colletotrichum have been reported as causal agents of anthracnose on crops and wild plants in Korea. Many Colletotrichum isolates from the country preserved in the Korean Agricultural Culture Collection (KACC) were previously identified based on host plants and morphological characteristics, and it may lead to species misidentification. Thus, accurate fungal species identification using multi-locus sequence analyses is essential for understanding disease epidemiology and disease management strategies. In this study, combined DNA sequence analyses of internal transcribed spacer, gapdh, chs-1, his3, act, tub2, and gs were applied to re-identify 27 Colletotrichum isolates in KACC. The phylogenetic analyses showed that the isolates resulted in 11 known species, they belong to the C. dematium species complex (C. hemerocallidis, C. jinshuiense, and C. spinaciae), the C. magnum complex (C. kaifengense and C. cf. ovatense), the C. orchidearum complex (C. cattleyicola, C. plurivorum, C. reniforme, and C. sojae) and the C. orbiculare complex (C. malvarum and C. orbiculare). Of them, C. cattleyicola, C. hemerocallidis, C. kaifengense, and C. reniforme were unrecorded species in Korea. In the view of host-fungus combinations, 10 combinations are newly reported in the world and 12 are new reports in Korea, although their pathogenicity on the host was not confirmed.

Palm fungi are a diverse and unique group mostly found on Arecaceae hosts. They have been studied for approximately 200 years resulting in a large number of known fungal species representing over 700 genera. The timeline of palm fungal studies could be roughly divided into three phases, based on the methods and frequency of reports. They are the “Historical palm fungi era”, “Classical palm fungi era” and “Molecular palm fungi era”. In the first two periods, the identification of palm fungi was based on morphology, which resulted in a considerable number of morphological species scattered across the data in books, monographs and papers. With the advancement of molecular techniques, studies on palm fungi accelerated. A large number of new species were introduced in the molecular era, especially from Asia, including China and Thailand. However, there is a necessity to link these three generations of studies into a single platform combining data related to host factors, geography and utilisation. Herein, we introduce the palm fungi website: https://palmfungi.org, an integrated data platform for interactive retrieval, based on palm and fungal species. This website is not only a portal for the latest, comprehensive species information on palm fungi, but also provides a new platform for fungal researchers to explore the host-specificity of palm fungi. Additionally, this study uses palmfungi.org and related data to briefly discuss the current status of research on the distribution of palm fungi populations, showing how palmfungi.org links fungi with their palm hosts. Furthermore, the website will act as a platform for collaboration amongst taxonomists, plant pathologists, botanists, ecologists and those who are interested in palms and their relationship with ecological sustainability.

Tuber aestivum, commonly known as the summer truffle, is typically found in various parts of Europe where it grows naturally. However, its presence in Portugal was not confirmed until now. The first fruit bodies were collected in April 2024 at stone pine stands (Alenquer and Arruda dos Vinhos, Lisbon) and in June at holm oak stands (Salir, Faro). These specimens are characterized by hypogeous, subglobose, black ascomata with a peridium surface covered with pyramidal warts. Ascopores are subglobose-to-broadly ellipsoid, distinctively ornamented, usually 1–6 per asci. According to the results of the internal transcribed spacer (ITS) rDNA sequence analysis, these specimens form a well-supported group within the Aestivum clade, with T. aestivum being the closest phylogenetic taxon. This remarkable discovery opens up new opportunities for truffle exploitation in Portugal thanks to the summer truffle’s gastronomical value and high market prices.

Tuber magnatum Picco, the Italian white truffle mushroom recorded for the first time in Türkiye, is a rare and economically valuable mushroom. Samples were collected from Sakarya province during field studies in 2024. The samples were identified as T. magnatum according to their macro- and microscopic features. To make molecular confirmation of the species, the samples' ITS1 and ITS4 gene regions were analysed and registered in Genbank with the number PP239641. The sample showed 100% compatibility with other T. magnatum accessions in Genbank. The distributions of Tuber species in Türkiye were given, and their taxonomic features were compared. [ABSTRACT FROM AUTHOR]

Little is known regarding the diversity patterns of Xylariaceae and Hypoxylaceae (Ascomycota) fungi taking part in the lignin decomposition of leaf litter from different tree species and under different climatic regions. The alpha and beta diversity of Xylariaceae and Hypoxylaceae fungi was investigated on bleached leaf litter from nine subtropical and cool temperate tree species in Japan. A total of 248 fungal isolates, obtained from 480 leaves from the nine tree species, were classified into 43 operational taxonomic units (OTUs) with a 97% similarity threshold and were assigned to nine genera of Xylariaceae and Hypoxylaceae. There was no overlap of fungal OTUs between subtropical and cool temperate trees. The mean number of fungal OTUs was generally higher in subtropical than cool temperate trees, whereas rarefaction curves depicting the numbers of OTU with respect to the number of leaves from which fungi were isolated were less steep in subtropical trees than in cool temperate trees, reflecting the dominance of major OTUs in the subtropical trees and indicating a higher species richness in cool temperate regions. Nonmetric multidimensional scaling showed general overlaps of fungal OTU compositions among tree species in the respective climatic regions, and one-way permutational multivariate analysis of variance indicated that the OTU composition was not significantly different between the tree species. These results suggest a wide host range and some geographic and climatic structures of distribution of these ligninolytic fungi. [ABSTRACT FROM AUTHOR]

Palm fungi are a diverse and unique group mostly found on Arecaceae hosts. They have been studied for approximately 200 years resulting in a large number of known fungal species representing over 700 genera. The timeline of palm fungal studies could be roughly divided into three phases, based on the methods and frequency of reports. They are the "Historical palm fungi era", "Classical palm fungi era" and "Molecular palm fungi era". In the first two periods, the identification of palm fungi was based on morphology, which resulted in a considerable number of morphological species scattered across the data in books, monographs and papers. With the advancement of molecular techniques, studies on palm fungi accelerated. A large number of new species were introduced in the molecular era, especially from Asia, including China and Thailand. However, there is a necessity to link these three generations of studies into a single platform combining data related to host factors, geography and utilisation. Herein, we introduce the palm fungi website: https://palmfungi.org, an integrated data platform for interactive retrieval, based on palm and fungal species. This website is not only a portal for the latest, comprehensive species information on palm fungi, but also provides a new platform for fungal researchers to explore the host-specificity of palm fungi. Additionally, this study uses palmfungi.org and related data to briefly discuss the current status of research on the distribution of palm fungi populations, showing how palmfungi.org links fungi with their palm hosts. Furthermore, the website will act as a platform for collaboration amongst taxonomists, plant pathologists, botanists, ecologists and those who are interested in palms and their relationship with ecological sustainability. [ABSTRACT FROM AUTHOR]

Bats (Chiroptera), the second largest group of mammals, are known for their unique immune system and their ability to act as vectors for various zoonoses. Bats also act as important carriers of fungi, which include plant, animal, and human pathogens. Their roosting areas, foraging behaviors, and even migration routes make bats ideal vectors for fungi. We isolated 75 culturable fungal species from bats in Yunnan Province, China, with 36 species representing known pathogens of plants, animals, and humans, while 39 species are non-pathogenic fungi. Among these species, 77% (58 species) belonged to Ascomycota, 9% (seven species) belonged to Basidiomycota, and 13% (10 species) belonged to Mucoromycota. Even though several taxonomic studies on fungi associated with bats have been published, studies exploring the role of bats as fungal vectors are lacking. This study discusses the fungi host-specific traits and pathogenicity and the impact and ecological significance of bats as fungal vectors. [ABSTRACT FROM AUTHOR]

Apple tree canker is a serious disease caused by species of Cytospora. Xinjiang Uygur Autonomous Region is one of the most important apple-producing areas in China. However, losses due to apple Cytospora canker have seriously damaged the apple industry and affected the economic development of the apple growers in this region. In this study, we used morphological characteristics combined with multilocus phylogenetic analyses of the ITS , act , rpb2 , tef1 and tub2 loci to identify isolates from apple (Malus domestica) and wild apple (M. sieversii). As a result, C. hippophaopsis sp. nov. from M. sieversii and C. shawanensis sp. nov. from M. domestica were discovered and proposed herein. Pathogenicity tests were further conducted on 13 varieties of apple and wild apple, which confirmed C. hippophaopsis and C. shawanensis as canker pathogens. Meanwhile, C. hippophaopsis is generally more aggressive than C. shawanensis on the tested varieties of apple and wild apple. [ABSTRACT FROM AUTHOR]

Six collections of ascomycetes were obtained from samples collected from dead branches and leaves of Juglans regia in Guizhou and Yunnan provinces, China. By incorporating multigene phylogenetic analysis (ITS , LSU , rpb2 , SSU , tef1-α , tub2) supplemented by morphological data, we establish two novel species, namely Helminthosporium guizhouense and Nigrospora yunnanensis. In morphology, H. guizhouense can be distinguished from H. caespitosum by its narrower conidia (13–16 µm vs. 27.3–35.5 µm), and N. yunnanensis is characterized by black, globose conidia (16.2 × 14.4 µm). The phylogenetic results further substantiated them as novel taxa. The present study contributes to our comprehension of the range of fungi found in Juglans regia, thereby expanding our knowledge of the diversity of fungi within this host. [ABSTRACT FROM AUTHOR]

During our investigation of microfungi on grasslands in Yunnan Province, China, three new fungal taxa associated with grasses were collected. Morphological observations and phylogenetic analyses of the combined SSU, LSU, ITS, tef1-α, and rpb2 loci based on maximum likelihood and Bayesian inference were used to reveal the taxonomic placement of these fungal taxa. This study introduces Parastagonospora yunnanensis, Para. zhaotongensis, Phaeoseptoriella poaceicola. Parastagonospora yunnanensis is characterized by ampulliform or globose to subglobose conidiogenous cells, with conidia that are cylindrical to subcylindrical, 0–1-septate, rounded at the apex and slightly truncate at the base. Parastagonospora zhaotongensis features similar globose to subglobose conidiogenous cells but with 0–3-septate, cylindrical to subcylindrical conidia. Phaeoseptoriella poaceicola is distinguished by its globose to subglobose conidiogenous cells and phragmosporous conidia that are initially hyaline, turn pale yellowish at maturity, and are 7-septate, cylindrical to subcylindrical, either straight or slightly curved. These discoveries underscore the significance of exploring and accurately identifying fungal taxa within Ascomycota, highlighting the species richness and potential for new species discoveries in grass-based habitats. The findings from this study expand our understanding of the taxonomy and phylogeny of grassland-associated Ascomycota, providing a foundation for further ecological and taxonomic studies of these fungi within their natural environments. [ABSTRACT FROM AUTHOR]

Bromo Tengger Semeru National Park (TNBTS) is a conservation area in East Java with an abundance of biodiversity, including macrofungi. This study aims to identify the macrofungal species existing in Poncokusumo district, TNBTS area, and their habitat characteristics for a further sustainable study of fungi. This study used a purposive sampling method by opportunistic exploration. Identification of macrofungi is conducted by morphological analysis and habitat characterization. The study identified 15 macrofungal species categorized as Ascomycota and Basidiomycota, that were distinct in their habitat characteristics. The 15 macrofungal species inhabited leaf litter, wood litter, soil, and bamboo. [ABSTRACT FROM AUTHOR]

Tuber aestivum, commonly known as the summer truffle, is typically found in various parts of Europe where it grows naturally. However, its presence in Portugal was not confirmed until now. The first fruit bodies were collected in April 2024 at stone pine stands (Alenquer and Arruda dos Vinhos, Lisbon) and in June at holm oak stands (Salir, Faro). These specimens are characterized by hypogeous, subglobose, black ascomata with a peridium surface covered with pyramidal warts. Ascopores are subglobose-to-broadly ellipsoid, distinctively ornamented, usually 1–6 per asci. According to the results of the internal transcribed spacer (ITS) rDNA sequence analysis, these specimens form a well-supported group within the Aestivum clade, with T. aestivum being the closest phylogenetic taxon. This remarkable discovery opens up new opportunities for truffle exploitation in Portugal thanks to the summer truffle's gastronomical value and high market prices. [ABSTRACT FROM AUTHOR]

In this survey, two wood-inhabiting species - Xylaria polymorpha and Xylaria longipes (10 strains each) were evaluated in dual culture assay against 6 fungi: Aspergillus niger, Candida albicans, Fusarium solani, Mucor plumbeus, Penicillium polonicum, and Trichoderma viride. Detailed descriptions of the interspecific interactions, morphological changes and comparison of X. longipes and X polymorpha reaction types with each fungus are provided. The results indicate significant inhibitory activity of both X. longipes and X. polymorpha against A. niger, M. plumbeus, P. polonicum, F. solani, C. albicans with differences in reaction types on a strain specific level. Most commonly, co-cultivating resulted in Xylaria species replacing fungi (60.8% of all interactions), with a partial replacement after initial deadlock with mycelial contact as the most frequent type of interaction. Inhibiting activity at a distance occurred in the majority of dual cultures of X. polymorpha with A. niger and P. polonicum (deadlock at a distance), and X. longipes with M. plumbeus (deadlock at a distance followed by a partial replacement). Among all tested cultures, T. viride turned out to be the only fungus suppressing Xylaria (except for X. polymorpha strains that formed a deadlock at mycelial contact). Based on the listed reaction types, for each studied Xylaria strain antagonism index was calculated, revealing that X polymorpha IBK 2720 had the highest value among all screened strains amounted to 20. The results indicate the effectiveness of Xylaria against tested fungi via contact antagonism and provide valuable insights for further investigations of novel biocontrol agents. [ABSTRACT FROM AUTHOR]

We studied the occurrence of endophytic fungi and bacteria in the roots of F. gigantea, a woodland perennial grass common throughout Europe and temperate Asia. The taxonomic assignment was carried out according to the isolate's colony and cytological species morphotype characteristics and confirmed by the assessment of the standard DNA sequences, ITS, RPB2, SSU, and TEF1-a for fungi and 16S rDNA for bacteria. Our study has shown that F. gigantea roots are the habitat to a wide range of fungi and bacteria. The occurrence of fungal structures was determined in ~40% of the roots examined by Trypan Blue staining. In a surface-sterile root-cutting culture on PDA medium, we obtained isolates of six endophytic fungi species: four members of Ascomycota—Alternaria alternata, Cadophora fastigiata, Chaetomium funicola, and Microdochium bolleyi—and two of Basidiomycota—Coprinellus sp. and Sistotrema brinkmannii. In addition, we report bacteria co-occurring endophytically in the roots of this grass. The Firmicutes group was the most prevalent, consisting of four Gram-positive, endospore-forming bacteria taxa. The isolates were identified as Bacillus pumilus, Bacillus sp., Lysinibacillus sp., and Priestia aryabhattai. Moreover, two Gram-negative bacteria were detected—Kosakonia sp. (Proteobacteria) and Pedobacter sp. (Bacteroidetes). Thus, applying the isolate-culture approach, we identified a set of microorganisms in the roots of a typical grass native to the deciduous forest floor. The functional roles of these endophytes are diverse, and many of them, saprotrophs and decomposers of wood and plant debris, are linked to the decomposition of organic matter. This is the first detailed report on fungal and bacterial endophytes inhabiting the roots of F. gigantea. This study fills in a research gap on endophytes associated with the below-ground parts of Festuca spp., hitherto extensively studied for Epichloë/Neotyphodium associations in their foliar parts. [ABSTRACT FROM AUTHOR]

BACKGROUND: Melanin plays important roles in morphological development, survival, host-pathogen interactions and in the virulence of phytopathogenic fungi. In Verticillum dahliae, increases in melanin are recognized as markers of maturation of microsclerotia which ensures the long-term survival and stress tolerance, while decreases in melanin are correlated with increased hyphal growth in the host. The conserved upstream components of the VdCmr1-regulated pathway controlling melanin production in V. dahliae have been extensively identified, but the direct activators of this pathway are still unclear. RESULTS: We identified two genes encoding conserved C2H2-type zinc finger proteins VdZFP1 and VdZFP2 adjacent to VdPKS9, a gene encoding a negative regulator of both melanin biosynthesis and microsclerotia formation in V. dahliae. Both VdZFP1 and VdZFP2 were induced during microsclerotia development and were involved in melanin deposition. Their localization changed from cytoplasmic to nuclear in response to osmotic pressure. VdZFP1 and VdZFP2 act as modulators of microsclerotia melanization in V. dahliae, as confirmed by melanin biosynthesis inhibition and supplementation with the melanin pathway intermediate scytalone in albino strains. The results indicate that VdZFP1 and VdZFP2 participate in melanin biosynthesis by positively regulating VdCmr1. Based on the results obtained with yeast one- and two-hybrid (Y1H and Y2H) and bimolecular fluorescence complementation (BiFC) systems, we determined the melanin biosynthesis relies on the direct interactions among VdZFP1, VdZFP2 and VdCmr1, and these interactions occur on the cell walls of microsclerotia. Additionally, VdZFP1 and/or VdZFP2 mutants displayed increased sensitivity to stress factors rather than alterations in pathogenicity, reflecting the importance of melanin in stress tolerance of V. dahliae. CONCLUSIONS: Our results revealed that VdZFP1 and VdZFP2 positively regulate VdCmr1 to promote melanin deposition during microsclerotia development, providing novel insight into the regulation of melanin biosynthesis in V. dahliae.

Invasive plant pathogenic fungi have a global impact, with devastating economic and environmental effects on crops and forests. Biosurveillance, a critical component of threat mitigation, requires risk prediction based on fungal lifestyles and traits. Recent studies have revealed distinct genomic patterns associated with specific groups of plant pathogenic fungi. We sought to establish whether these phytopathogenic genomic patterns hold across diverse taxonomic and ecological groups from the Ascomycota and Basidiomycota, and furthermore, if those patterns can be used in a predictive capacity for biosurveillance. Using a supervised machine learning approach that integrates phylogenetic and genomic data, we analyzed 387 fungal genomes to test a proof-of-concept for the use of genomic signatures in predicting fungal phytopathogenic lifestyles and traits during biosurveillance activities. Our machine learning feature sets were derived from genome annotation data of carbohydrate-active enzymes (CAZymes), peptidases, secondary metabolite clusters (SMCs), transporters, and transcription factors. We found that machine learning could successfully predict fungal lifestyles and traits across taxonomic groups, with the best predictive performance coming from feature sets comprising CAZyme, peptidase, and SMC data. While phylogeny was an important component in most predictions, the inclusion of genomic data improved prediction performance for every lifestyle and trait tested. Plant pathogenicity was one of the best-predicted traits, showing the promise of predictive genomics for biosurveillance applications. Furthermore, our machine learning approach revealed expansions in the number of genes from specific CAZyme and peptidase families in the genomes of plant pathogens compared to non-phytopathogenic genomes (saprotrophs, endo- and ectomycorrhizal fungi). Such genomic feature profiles give insight into the evolution of fungal phytopathogenicity and could be useful to predict the risks of unknown fungi in future biosurveillance activities.

Verticillium dahliae is a soilborne fungal pathogen that causes disease on many economically important crops. Based on the resistance or susceptibility of differential cultivars in tomato, isolates of V. dahliae are divided into three races. Avirulence (avr) genes within the genomes of the three races have also been identified. However, the functional role of the avr gene in race 3 isolates of V. dahliae has not been characterized. In this study, bioinformatics analysis showed that VdR3e, a cysteine-rich secreted protein encoded by the gene characterizing race 3 in V. dahliae, was likely obtained by horizontal gene transfer from the fungal genus Bipolaris. We demonstrate that VdR3e causes cell death by triggering multiple defense responses. In addition, VdR3e localized at the periphery of the plant cell and triggered immunity depending on its subcellular localization and the cell membrane receptor BAK1. Furthermore, VdR3e is a virulence factor and shows differential pathogenicity in race 3-resistant and -susceptible hosts. These results suggest that VdR3e is a virulence factor that can also interact with BAK1 as a pathogen-associated molecular pattern (PAMP) to trigger immune responses. IMPORTANCE Based on the gene-for-gene model, research on the function of avirulence genes and resistance genes has had an unparalleled impact on breeding for resistance in most crops against individual pathogens. The soilborne fungal pathogen, Verticillium dahliae, is a major pathogen on many economically important crops. Currently, avr genes of the three races in V. dahliae have been identified, but the function of avr gene representing race 3 has not been described. We investigated the characteristics of VdR3e-mediated immunity and demonstrated that VdR3e acts as a PAMP to activate a variety of plant defense responses and induce plant cell death. We also demonstrated that the role of VdR3e in pathogenicity was host dependent. This is the first study to describe the immune and virulence functions of the avr gene from race 3 in V. dahliae, and we provide support for the identification of genes mediating resistance against race 3.

BACKGROUND: The extracellular space between the cell wall and plasma membrane is a battlefield in plant-pathogen interactions. Within this space, the pathogen employs its secretome to attack the host in a variety of ways, including immunity manipulation. However, the role of the plant secretome is rarely studied for its role in disease resistance. RESULTS: Here, we examined the secretome of Verticillium wilt-resistant Gossypium hirsutum cultivar Zhongzhimian No.2 (ZZM2, encoding 95,327 predicted coding sequences) to determine its role in disease resistance against the wilt causal agent, Verticillium dahliae. Bioinformatics-driven analyses showed that the ZZM2 genome encodes 2085 secreted proteins and that these display disequilibrium in their distribution among the chromosomes. The cotton secretome displayed differences in the abundance of certain amino acid residues as compared to the remaining encoded proteins due to the localization of these putative proteins in the extracellular space. The secretome analysis revealed conservation for an allotetraploid genome, which nevertheless exhibited variation among orthologs and comparable unique genes between the two sub-genomes. Secretome annotation strongly suggested its involvement in extracellular stress responses (hydrolase activity, oxidoreductase activity, and extracellular region, etc.), thus contributing to resistance against the V. dahliae infection. Furthermore, the defense response genes (immunity marker NbHIN1, salicylic acid marker NbPR1, and jasmonic acid marker NbLOX4) were activated to varying degrees when Nicotina benthamiana leaves were agro-infiltrated with 28 randomly selected members, suggesting that the secretome plays an important role in the immunity response. Finally, gene silencing assays of 11 members from 13 selected candidates in ZZM2 displayed higher susceptibility to V. dahliae, suggesting that the secretome members confer the Verticillium wilt resistance in cotton. CONCLUSIONS: Our data demonstrate that the cotton secretome plays an important role in Verticillium wilt resistance, facilitating the development of the resistance gene markers and increasing the understanding of the mechanisms regulating disease resistance.

Abstract The present study brings the first report of species of Chaetomium and Humicola from Bahia state. Chaetomium globosum was isolated from different substrates of cacao, jackfruit, papaya and soursop and C. pseudoglobosum from cow dung. Humicola cuyabenoensis was isolated from soil samples of cacao plantations in the southeast Bahia.

BackgroundColonization of the human gut and tumor tissue by non-pathogenic fungi has emerged as a potential risk factor associated with cancer epidemics. Therefore, we aimed to conduct a systematic review to assess the role of fungal colonization in gastrointestinal (GI) tumors in increasing diagnostic efficiency.MethodsA PubMed citation search was conducted for publications up to and including March 2023, followed by full-text screening. Results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. According to the Patient, Intervention, Comparison, Outcome (PICO) framework, patients diagnosed with early-and advanced-stage GI cancers, GI adenoma patients, and healthy subjects were included with metagenomic (MG) or internal transcribed spacer (ITS) sequencing on tumor tissue, adjacent normal tissue, stool, and blood samples.ResultsFourteen studies were eligible based on the inclusion criteria and methodological quality. Studies were conducted in stool (n = 8) or tissue (n = 7) as the most common specimens to be used for molecular analysis. In the collected data, ITS was used in n = 10 cases and metagenomic analyses in n = 3 cases. Observing the interindividual variability, we found that the Ascomycota/Basidiomycota (A/B) ratio from healthy to cancer state decreased in n = 2, increased in n = 1 cases, and did not change significantly in n = 2 studies. An increase in the relative abundance of Malassezia was identified in n = 4, of Candida in n = 5, of Saccharomyces in n = 2, and of Aspergillus in n = 2 cases. Intraindividual differences in the A/B ratio were identified in cancer and adjacent tissue (n = 4) and cancer vs. stool (n = 1) studies. Intraindividual variability of the A/B ratio showed an increase in n = 2 and no change in n = 3 studies for cancer tissue.ConclusionIn conclusion, the advent of highly sensitive sequencing methods may aid in the identification and the differentiation of cancerous from healthy human fungal colonizations with potential future diagnostic applications. Further studies are needed to establish reliable biomarkers for GI cancer screening.

A new species of Helicascus satunensis sp. nov. was collected on mature dead fruits of the Nypa palm in Satun Province, southern Thailand. Its morphological characteristics are similar to those of the genus Helicascus. Recently, a genus Helicascus with three species from marine habitats worldwide was studied. The morphology of this fungus was investigated and combined with multigene sequence analyzes of small subunit (SSU), large subunit (LSU), internal transcribed spacer (ITS) ribosomal DNA, translation elongation factor 1-alpha (TEF-1α) and RNA polymerase II (RPB2) genes. Morphologically, H. satunensis sp. nov. is characterized by semi-immersed, lenticular ascomata, multilocules, a bitunicate ascus and smooth, obovoid, dark brown ascospores that are one-septate and unequally two-celled. In addition, 3D visualization using synchrotron X-ray tomography was performed to investigate the interaction between fruiting body and substrata. Molecular phylogeny with multigene revealed that H. satunensis sp. nov. belongs to the family Morosphaeriaceae, order Pleosporales, class Dothideomycetes. Furthermore, H. satunensis sp. nov. forms a well-supported clade with Helicascus species described from marine habitats. Based on the unique morphological and molecular evidence, we propose this fungus, H. satunensis sp. nov., as a new species for Helicascus.

Despite their global presence and ubiquity, members of the class Geoglossomycetes (Pezizomycotina, Ascomycota) are understudied systematically and ecologically. These fungi have long been presumed saprobic due to their occurrence in or near leaf litter and soils. Additionally, they lack an apparent association with other organisms, reinforcing this perception. However, observations of sporocarps near ericaceous shrubs have given rise to an alternative hypothesis that members of Geoglossomycetes may form ericoid mycorrhizae or ectomycorrhizae. This claim, however, has yet to be confirmed via microscopy or amplicon-based studies examining root communities. As a result, our current understanding of their ecology is based on cursory observations. This study presents a comparative analysis of genomic signatures related to ecological niche to investigate the hypothesis of an ericoid mycorrhizal or ectomycorrhizal ecology in the class. We compared the carbohydrate-active enzyme (CAZyme) and secondary metabolite contents of six newly sequenced Geoglossomycetes genomes with those of fungi representing specific ecologies across Pezizomycotina. Our analysis reveals CAZyme and secondary metabolite content patterns consistent with ectomycorrhizal (EcM) members of Pezizomycotina. Specifically, we found a reduction in CAZyme-encoding genes and secondary metabolite clusters that suggests a mutualistic ecology. Our work includes the broadest taxon sampling for a phylogenomic study of Pezizomycotina to date. It represents the first functional genomic and genome-scale phylogenetic study of the class Geoglossomycetes and improves the foundational knowledge of the ecology and evolution of these understudied fungi.

Verticillium wilt caused by Verticillium dahliae is a notorious soil-borne fungal disease and seriously threatens the yield of economic crops worldwide. During host infection, V. dahliae secretes many effectors that manipulate host immunity, among which small cysteine-rich proteins (SCPs) play an important role. However, the exact roles of many SCPs from V. dahliae are unknown and varied. In this study, we show that the small cysteine-rich protein VdSCP23 inhibits cell necrosis in Nicotiana benthamiana leaves, as well as the reactive oxygen species (ROS) burst, electrolyte leakage and the expression of defense-related genes. VdSCP23 is mainly localized in the plant cell plasma membrane and nucleus, but its inhibition of immune responses was independent of its nuclear localization. Site-directed mutagenesis and peptide truncation showed that the inhibition function of VdSCP23 was independent of cysteine residues but was dependent on the N-glycosylation sites and the integrity of VdSCP23 protein structure. Deletion of VdSCP23 did not affect the growth and development of mycelia or conidial production in V. dahliae. Unexpectedly, VdSCP23 deletion strains still maintained their virulence for N. benthamiana, Gossypium hirsutum and Arabidopsis thaliana seedlings. This study demonstrates an important role for VdSCP23 in the inhibition of plant immune responses; however, it is not required for normal growth or virulence in V. dahliae.

Fulvia fulva and Dothistroma septosporum are closely related apoplastic pathogens with similar lifestyles but different hosts: F. fulva is a pathogen of tomato, whilst D. septosporum is a pathogen of pine trees. In 2012, the first genome sequences of these pathogens were published, with F. fulva and D. septosporum having highly fragmented and near-complete assemblies, respectively. Since then, significant advances have been made in unravelling their genome architectures. For instance, the genome of F. fulva has now been assembled into 14 chromosomes, 13 of which have synteny with the 14 chromosomes of D. septosporum, suggesting these pathogens are even more closely related than originally thought. Considerable advances have also been made in the identification and functional characterization of virulence factors (e.g., effector proteins and secondary metabolites) from these pathogens, thereby providing new insights into how they promote host colonization or activate plant defence responses. For example, it has now been established that effector proteins from both F. fulva and D. septosporum interact with cell-surface immune receptors and co-receptors to activate the plant immune system. Progress has also been made in understanding how F. fulva and D. septosporum have evolved with their host plants, whilst intensive research into pandemics of Dothistroma needle blight in the Northern Hemisphere has shed light on the origins, migration, and genetic diversity of the global D. septosporum population. In this review, we specifically summarize advances made in our understanding of the F. fulva-tomato and D. septosporum-pine pathosystems over the last 10 years.

In 1970, the Southern Corn Leaf Blight epidemic ravaged U.S. fields to great economic loss. The outbreak was caused by never-before-seen, supervirulent, Race T of the fungus Cochliobolus heterostrophus. The functional difference between Race T and O, the previously known, far less aggressive strain, is production of T-toxin, a host-selective polyketide. Supervirulence is associated with ~1 Mb of Race T-specific DNA; only a fraction encodes T-toxin biosynthetic genes (Tox1). Tox1 is genetically and physically complex, with unlinked loci (Tox1A, Tox1B) genetically inseparable from breakpoints of a Race O reciprocal translocation that generated hybrid Race T chromosomes. Previously, we identified 10 genes for T-toxin biosynthesis. Unfortunately, high-depth, short-read sequencing placed these genes on four small, unconnected scaffolds surrounded by repeated A+T rich sequence, concealing context. To sort out Tox1 topology and pinpoint the hypothetical Race O translocation breakpoints corresponding to Race T-specific insertions, we undertook PacBio long-read sequencing which revealed Tox1 gene arrangement and the breakpoints. Six Tox1A genes are arranged as three small islands in a Race T-specific sea (~634 kb) of repeats. Four Tox1B genes are linked, on a large loop of Race T-specific DNA (~210 kb). The race O breakpoints are short sequences of race O-specific DNA; corresponding positions in race T are large insertions of race T-specific, A+T rich DNA, often with similarity to transposable (predominantly Gypsy) elements. Nearby, are 'Voyager Starship' elements and DUF proteins. These elements may have facilitated Tox1 integration into progenitor Race O and promoted large scale recombination resulting in race T. IMPORTANCE In 1970 a corn disease epidemic ravaged fields in the United States to great economic loss. The outbreak was caused by a never-before seen, supervirulent strain of the fungal pathogen Cochliobolus heterostrophus. This was a plant disease epidemic, however, the current COVID-19 pandemic of humans is a stark reminder that novel, highly virulent, pathogens evolve with devastating consequences, no matter what the host-animal, plant, or other organism. Long read DNA sequencing technology allowed in depth structural comparisons between the sole, previously known, much less aggressive, version of the pathogen and the supervirulent version and revealed, in meticulous detail, the structure of the unique virulence-causing DNA. These data are foundational for future analysis of mechanisms of DNA acquisition from a foreign source.

Blast disease in cereal plants is caused by the fungus Magnaporthe oryzae and accounts for a significant loss in food crops. At the outset of infection, expression of a putative polysaccharide monooxygenase (MoPMO9A) is increased. MoPMO9A contains a catalytic domain predicted to act on cellulose and a carbohydrate-binding domain that binds chitin. A sequence similarity network of the MoPMO9A family AA9 showed that 220 of the 223 sequences in the MoPMO9A-containing cluster of sequences have a conserved unannotated region with no assigned function. Expression and purification of the full length and two MoPMO9A truncations, one containing the catalytic domain and the domain of unknown function (DUF) and one with only the catalytic domain, were carried out. In contrast to other AA9 polysaccharide monooxygenases (PMOs), MoPMO9A is not active on cellulose but showed activity on cereal-derived mixed (1→3, 1→4)-β-D-glucans (MBG). Moreover, the DUF is required for activity. MoPMO9A exhibits activity consistent with C4 oxidation of the polysaccharide and can utilize either oxygen or hydrogen peroxide as a cosubstrate. It contains a predicted 3-dimensional fold characteristic of other PMOs. The DUF is predicted to form a coiled-coil with six absolutely conserved cysteines acting as a zipper between the two α-helices. MoPMO9A substrate specificity and domain architecture are different from previously characterized AA9 PMOs. The results, including a gene ontology analysis, support a role for MoPMO9A in MBG degradation during plant infection. Consistent with this analysis, deletion of MoPMO9A results in reduced pathogenicity.

Diseased trees were found in Tectona grandis plantations in the province of Guanacaste, Costa Rica, showing symptoms of collar and root rot. At the morphological and molecular level, the species Kretzschmaria zonata was identified as the causal agent of the disease. The pathogen's mycelium grew in a concentric form on PDA medium, with a gray coloration in the center and a white one at the edges. Dark brown ascospores were recorded, measuring (21.6-) 27.4 - 32.1 (-33.5) x (6.2-) 8.7 - 10.9 (-11.8) µm. Plants inoculated with the pathogen developed lesions, with highly significant differences compared to control plants. Re-isolations were performed, and the fungus K. zonata was recovered, fulfilling Koch's postulates. This is the first time that this pathogen has been reported as causing disease in teak forest plantations in Costa Rica, which constitutes an advancement in the study of management strategies regarding this disease. [ABSTRACT FROM AUTHOR]

DNA barcodes can provide accurate identification of plants. We used previously reported DNA primers targeting the internal transcribed spacer (ITS1) region of the nuclear ribosomal cistron, internal transcribed spacer (ITS2), and chloroplast trnL (UAA) intron to identify four trees at Bergen Community College. Two of the four trees were identified as Acer rubrum and Fagus sylvatica. However, Quercus was only identified at the genus level, and the fourth tree did not show similar identification between barcodes. Next-generation sequencing of 16S rRNA genes showed that the predominant bacterial communities in the rhizosphere mainly consisted of the Pseudomonadota, Actinomycetota, Bacteroidota, and Acidobacteriota. A. rubrum showed the most diverse bacterial community while F. sylvatica was less diverse. The genus Rhodoplanes showed the highest relative bacterial abundance in all trees. Fungal ITS sequence analysis demonstrated that the communities predominantly consisted of the Ascomycota and Basidiomycota. Quercus showed the highest fungi diversity while F. sylvatica showed the lowest. Russula showed the highest abundance of fungi genera. Average similarity values in the rhizosphere for fungi communities at the phylum level were higher than for bacteria. However, at the genus level, bacterial communities showed higher similarities than fungi. Similarity values decreased at lower taxonomical levels for both bacteria and fungi, indicating each tree has selected for specific bacterial and fungal communities. This study confirmed the distinctiveness of the microbial communities in the rhizosphere of each tree and their importance in sustaining and supporting viability and growth but also demonstrating the limitations of DNA barcoding with the primers used in this study to identify genus and species for some of the trees. The optimization of DNA barcoding will require additional DNA sequences to enhance the resolution and identification of trees at the study site. [ABSTRACT FROM AUTHOR]

Fungi harbor a vast diversity of mobile genetic elements (MGEs). Recently, novel fungal MGEs, tentatively referred to as ‘ambiviruses,’ were described. ‘Ambiviruses’ have single-stranded RNA genomes of about 4–5 kb in length that contain at least two open reading frames (ORFs) in non-overlapping ambisense orientation. Both ORFs are conserved among all currently known ‘ambiviruses,’ and one of them encodes a distinct viral RNA-directed RNA polymerase (RdRP), the hallmark gene of ribovirian kingdom Orthornavirae. However, ‘ambivirus’ genomes are circular and predicted to replicate via a rolling-circle mechanism. Their genomes are also predicted to form rod-like structures and contain ribozymes in various combinations in both sense and antisense orientations—features reminiscent of viroids, virusoids, ribozyvirian kolmiovirids, and yet-unclassified MGEs (such as ‘epsilonviruses,’ ‘zetaviruses,’ and some ‘obelisks’). As a first step toward the formal classification of ‘ambiviruses,’ the International Committee on Taxonomy of Viruses (ICTV) recently approved the establishment of a novel ribovirian phylum, Ambiviricota, to accommodate an initial set of 20 members with well-annotated genome sequences. [ABSTRACT FROM AUTHOR]