Photosynthesis measurements on the upper and lower side of the thallus of the foliose lichen Nephroma arcticum (L.) Torss.

The measurements of chlorophyll fluorescence play an important role in studies of lichen physiology. Usually, for foliose lichens fluorescence kinetics is recorded from the upper thalline side often exhibiting green color reflecting the presence of photosynthetic pigments. The lower side of such lichens is grey, dark-brown or black. At the first time, we evaluated photosynthetic activity distribution by chlorophyll fluorescence analysis on both lower and upper thallus sides for the foliose lichen Nephroma arcticum. We have demonstrated that photosynthesis proceeds not only on the green-colored upper side, but also on the gray lower side of the curled growing edges of the thallus lobes. These sides were differed in terms of PSII photochemical quantum yield, activity of non-regulatory dissipation and non-photochemical quenching of excited chlorophyll states (NPQ). Upper side was characterized by higher maximal PSII efficiency, whereas the lower one of the curled edges was characterized by higher actual photochemical quantum yield during actinic light acclimation. NPQ was higher on the upper surface, whereas, on the lower side (of the curled edges) non-regulatory dissipation was predominant. In terms of photosynthetic activity measurements, these results show, that actinic and measuring light reached the layer of phycobiont despite its shielding by mycobiont hyphae. On the melanized lower side in the basal thalline zone attached to the substratum photosynthesis was not detected. Lower side demonstrated higher level of light scattering in the reflectance spectra. We believe that different photoprotective mechanisms against high light are crucial on the upper and lower sides: NPQ on the upper surface, and light scattering and shielding by mycobiont on the lower side. Possible biological role of photosynthesis on the lower side is discussed.

Modulation of fungal virulence through CRZ1 regulated F-BAR-dependent actin remodeling and endocytosis in chickpea infecting phytopathogen Ascochyta rabiei.

Polarized hyphal growth of filamentous pathogenic fungi is an essential event for host penetration and colonization. The long-range early endosomal trafficking during hyphal growth is crucial for nutrient uptake, sensing of host-specific cues, and regulation of effector production. Bin1/Amphiphysin/Rvs167 (BAR) domain-containing proteins mediate fundamental cellular processes, including membrane remodeling and endocytosis. Here, we identified a F-BAR domain protein (ArF-BAR) in the necrotrophic fungus Ascochyta rabiei and demonstrate its involvement in endosome-dependent fungal virulence on the host plant Cicer arietinum. We show that ArF-BAR regulates endocytosis at the hyphal tip, localizes to the early endosomes, and is involved in actin dynamics. Functional studies involving gene knockout and complementation experiments reveal that ArF-BAR is necessary for virulence. The loss-of-function of ArF-BAR gene results in delayed formation of apical septum in fungal cells near growing hyphal tip that is crucial for host penetration, and impaired secretion of a candidate effector having secretory signal peptide for translocation across the endoplasmic reticulum membrane. The mRNA transcripts of ArF-BAR were induced in response to oxidative stress and infection. We also show that ArF-BAR is able to tubulate synthetic liposomes, suggesting the functional role of F-BAR domain in membrane tubule formation in vivo. Further, our studies identified a stress-induced transcription factor, ArCRZ1 (Calcineurin-responsive zinc finger 1), as key transcriptional regulator of ArF-BAR expression. We propose a model in which ArCRZ1 functions upstream of ArF-BAR to regulate A. rabiei virulence through a mechanism that involves endocytosis, effector secretion, and actin cytoskeleton regulation.

Effectors with chitinase activity (EWCAs), a family of conserved, secreted fungal chitinases that suppress chitin-triggered immunity.

In plants, chitin-triggered immunity is one of the first lines of defense against fungi, but phytopathogenic fungi have developed different strategies to prevent the recognition of chitin. Obligate biotrophs such as powdery mildew fungi suppress the activation of host responses; however, little is known about how these fungi subvert the immunity elicited by chitin. During epiphytic growth, the cucurbit powdery mildew fungus Podosphaera xanthii expresses a family of candidate effector genes comprising nine members with an unknown function. In this work, we examine the role of these candidates in the infection of melon (Cucumis melo L.) plants, using gene expression analysis, RNAi silencing assays, protein modeling and protein-ligand predictions, enzymatic assays, and protein localization studies. Our results show that these proteins are chitinases that are released at pathogen penetration sites to break down immunogenic chitin oligomers, thus preventing the activation of chitin-triggered immunity. In addition, these effectors, designated effectors with chitinase activity (EWCAs), are widely distributed in pathogenic fungi. Our findings reveal a mechanism by which fungi suppress plant immunity and reinforce the idea that preventing the perception of chitin by the host is mandatory for survival and development of fungi in plant environments.

Prey sensing and response in a nematode-trapping fungus is governed by the MAPK pheromone response pathway.

Detection of surrounding organisms in the environment plays a major role in the evolution of interspecies interactions, such as predator-prey relationships. Nematode-trapping fungi (NTF) are predators that develop specialized trap structures to capture, kill, and consume nematodes when food sources are limited. Despite the identification of various factors that induce trap morphogenesis, the mechanisms underlying the differentiation process have remained largely unclear. Here, we demonstrate that the highly conserved pheromone-response MAPK pathway is essential for sensing ascarosides, a conserved molecular signature of nemaotdes, and is required for the predatory lifestyle switch in the NTF Arthrobotrys oligospora. Gene deletion of STE7 (MAPKK) and FUS3 (MAPK) abolished nematode-induced trap morphogenesis and conidiation and impaired the growth of hyphae. The conserved transcription factor Ste12 acting downstream of the pheromone-response pathway also plays a vital role in the predation of A. oligospora. Transcriptional profiling of a ste12 mutant identified a small subset of genes with diverse functions that are Ste12 dependent and could trigger trap differentiation. Our work has revealed that A. oligospora perceives and interprets the ascarosides produced by nematodes via the conserved pheromone signaling pathway in fungi, providing molecular insights into the mechanisms of communication between a fungal predator and its nematode prey.

New genus of trichomatous coelomycete on Myrcia fenzliana from the Brazilian Cerrado.

Megacoelomyces (type species: Megacoelomyces sanchezii), an ascomycete asexual morph infecting Myrcia fenzliana (Myrtaceae) from the Brazilian Cerrado, is described as a new genus in the Phaeosphaeriaceae (Pleosporales, Dothideomycetes, Ascomycota), based on multilocus phylogeny (three nuclear ribosomal DNA and two protein-coding genes) in addition to morphological (light and scanning electron microscopy) and ecological data.

Metaproteomics reveals the structural and functional diversity of Dermatocarpon miniatum (L.) W. Mann. Microbiota.

Metaproteomics is a strategy to understand the taxonomy, functionality and metabolic pathways of the microbial communities. The relationship among the symbiotic microbiota in the entire lichen thallus, Dermatocarpon miniatum, was evaluated using the metaproteomic approach. Proteomic profiling using one-dimensional SDS-PAGE followed by LC-MS/MS analysis resulted in a total of 138 identified proteins via Mascot search against UniRef100 and Swiss-Prot databases. In addition to the fungal and algal partners, D. miniatum proteome encompasses proteins from prokaryotes, which is a multifarious community mainly dominated by cyanobacteria and proteobacteria. While proteins assigned to fungus were the most abundant (55 %), followed by protists (16 %), bacterial (13 %), plant (11 %), and viral (1 %) origin, whereas 4 % remained undefined. Various proteins were assigned to the different lichen symbionts by using Gene Ontology (GO) terms, e.g. fungal proteins involved in the oxidation-reduction process, protein folding and glycolytic process, while protists and bacterial proteins were involved in photosynthetic electron transport in photosystem II (PS II), ATP synthesis coupled proton transport, and carbon fixation. The presence of bacterial communities extended the traditional concept of fungal-algal lichen symbiotic interaction.

Dynamics of Chemical Diversity during Co-Cultures: An Integrative Time-Scale Metabolomics Study of Fungal Endophytes Cophinforma mamane and Fusarium solani.

A rapid and efficient metabolomic study of Cophinforma mamane and Fusarium solani co-cultivation in time-series based analysis was developed to study metabolome variations during their fungal interactions. The fungal metabolomes were studied through the integration of four metabolomic tools: MS-DIAL, a chromatographic deconvolution of liquid-chromatography-mass spectrometry (LC/MS); MS-FINDER, a structure-elucidation program with a wide range metabolome database; GNPS, an effective method to organize MS/MS fragmentation spectra, and MetaboAnalyst, a comprehensive web application for metabolomic data analysis and interpretation. Co-cultures of C. mamane and F. solani induced different patterns of metabolite production over 10 days of incubation and induced production of five de novo compounds not occurring in monocultures. These results emphasize that co-culture in time-frame analysis is an interesting method to unravel hidden metabolome in the investigation of fungal chemodiversity.

Neoscytalidium dimidiatum un raro agente de onicomicosis no dermatofítica en Chile / Neoscytalidium dimidiatuma rare agent ofnon dermatophyticonychomycosisin Chile

El término de onicomicosis se emplea para describir las infecciones de las uñas causadas por diferentes grupos taxonómicos fúngicos ya sea filamentosos como levaduriformes. A pesar de que estas patologías son causadas en los vertebrados principalmente por integrantes de la Familia Artrodermatáceae (Onygenales), la micología médica aplicó para ellos la terminología más específica de dermatofitosis, por ser un grupo ecológico de mayor importancia y presencia clínica. Las dermatomicosis de piel y fanéreos, representan un conjunto de infecciones producidas por especies fúngicas distribuidas en ambientes diversos, capaces de crecer a temperaturas de 37° y que actúan usualmente como patógenos oportunistas cuando existe generalmente un factor predisponente en el huésped. Se destaca la colonización en una uña de los pies en un hombre de 49 años por Neoscytalidium dimidiatum(Penz.) Crous & Slippers, un reconocido fitopatógeno de rápido crecimiento, común en zonas tropicales y subtropicales, que presentó la capacidad de invadir tejidos queratinizados con un aspecto clínico indistinguible de los causadas por dermatofitos. Por la rara presencia de este hongo en nuestra zona geográfica (provincia de Valparaíso, Chile), se aportan los principales datos morfofisiológicos,taxonómicos y moleculares utilizados en su diagnóstico. (AU)

The term onychomycosis is used to describe nail infections caused by different fungal taxonomic groups, either filamentous or yeast. Despite the fact that these pathologies are caused in vertebrates mainly by members of the Artrodermatáceae Family (Onygenales), medical mycology applied the more specific terminology of dermatophytosis for them, as it is an ecological group of greater importance and clinical presence. Skin and pharynx dermatomycosis represent a set of infections produced by fungal species distributed in diverse environments, capable of growing at temperatures of 37° and that usually act as opportunistic pathogens when there is a predisposing factor in the host. The colonization on a toenail in a 49-year-old man by Nesoscytalidium dimidiatumis highlighted (Penz.) Crous & Slippers, a recognized fast-growing phytopathogen, common in tropical and subtropical areas, which presented the ability to invade keratinized tissues with a clinical appearance indistinguishable from those caused by dermatophytes. Due to the rare presence of this fungus in our geographical area (Valparaíso province, Chile), the main morphophysiological, taxonomic and molecular data used in its identificationare provided. (AU)

Function of PoLAE2, a laeA homolog, in appressorium formation and cAMP signal transduction in Pyricularia oryzae.

A novel homolog of laeA, a global regulatory gene in filamentous fungi, was identified from Pyricularia oryzae. A deletion mutant of the homolog (PoLAE2) exhibited lowered intracellular cAMP levels, and decreased appressorium formation on non-host surface; the decrease was recovered using exogenous cAMP and IBMX, indicating that PoLAE2 deletion affected the cAMP signaling pathway.

Tuber iranicum, sp. nov., a truffle species belonging to the Excavatum clade.

Truffles in the genus Tuber are hypogeus fungi that have a worldwide distribution. Despite this, knowledge about their diversity in the Middle East is very limited. In recent years, large quantities of truffles have been imported from Iran for being sold in Italy. While analyzing certain commercial batches of T. aestivum from Iran, we found some ascomata that resembled T. excavatum but had macro- and micromorphological features that were distinct from this species. They were subglobose, or depressed to slightly irregular, with a conspicuous basal cavity, grayish brown, brown, or pinkish gray, with a minutely papillose peridium. The gleba was pinkish gray in youth, brown at maturity, marbled with cream branched veins. Ascospores were broadly ellipsoid, with an irregular reticulum and distinctive long crests along the longitudinal axis, up to 9 µm high. Analysis of internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences showed that these specimens form a monphyletic and well-supported taxon within the Excavatum clade. Morphological and molecular analyses supported the proposal of the new species T. iranicum.

The new truffle genus Babosia and a new species of Stouffera from semiarid grasslands of Hungary.

Truffles with distinct morphological and anatomical features were collected during a study of hypogeous fungi of semiarid sandy grasslands of the Great Hungarian Plain in Hungary, representing the westernmost localities of the Eurasian steppe belt. None of the ascomata were collected near ectomycorrhizal plant species, and none were identified as ectomycorrhizal during previous surveys in the collection area. We studied morphoanatomical characteristics of these truffles with light and scanning electron microscopy and investigated their phylogenetic positions based on analyses of different nuclear loci. The truffles were found to represent two novel lineages that grouped with the Marcelleina-Peziza gerardii clade of the Pezizaceae. One formed a distinct lineage, for which we propose a new genus Babosia with a new species Babosia variospora characterized by diverse spore ornamentation varying even within one ascus. The truffles in the other lineage clustered with the rarely collected American truffle Stouffera longii and share with it similar spore ornamentation and habitat features. However, our material differs from S. longii by geographic origin, the quick and strong coloration of the ascomata to dark gray at cut surface or bruised area, varying spore number in asci, and smaller spore size; thus, we describe it as a new species, Stouffera gilkeyae.

Large-spored Drechslera gigantea is a Bipolaris species causing disease on the invasive grass Microstegium vimineum.

Environmentally damaging invasive plants can also serve as reservoir hosts for agricultural pathogens. Microstegium vimineum is an invasive C4 annual grass that is present throughout the midwestern and eastern United States. It can reach high densities in disturbed areas such as crop-forest interfaces, which creates the potential for pathogen spillover from M. vimineum to agricultural crops and native plants. A previous study that surveyed disease on M. vimineum found a large-spored Bipolaris species that was widespread on M. vimineum and also isolated from co-occurring native grasses. Here, we report that the large-spored fungus isolated from M. vimineum and the native grass Elymus virginicus is Drechslera gigantea, based on comparison with published descriptions of morphological traits, and establish that D. gigantea is a pathogen of M. vimineum and E. virginicus. We review the phylogenetic placement and taxonomic history of D. gigantea and propose that it be reassigned to the genus Bipolaris as Bipolaris gigantea.

Cladosterigma: an enigmatic fungus, previously considered a basidiomycete, now revealed as an ascomycete member of the Gomphillaceae.

Cladosterigma clavariellum has been treated as a basidiomycete since its first description by Spegazzini in 1886 as Microcera clavariella. After further morphological studies, between 1919 and 2011, it remained among the basidiomycetes, most recently as incertae sedis in the order Cryptobasidiales. Our studies, based on light and scanning electron microscopy, supported by multilocus phylogenetic analyses-second-largest subunit of RNA polymerase II (RPB2), translation elongation factor 1-alpha (TEF1), small subunit (18S), large subunit (28S), and nuclear internal transcribed spacers (ITS1-5.8S-ITS2 = ITS) of the nuclear rDNA sequences, and mitochondrial rDNA small subunit (mtSSU)-finally determined the phylogenetic placement of Cladosterigma as the first nonlichenicolous mycoparasitic member of the Gomphillaceae within the Graphidales, an ascomycete order previously composed predominantly of lichen-forming fungi.

Fungal spore adhesion on glycidoxypropyltrimethoxy silane modified silica nanoparticle surfaces as revealed by single cell force spectroscopy.

Thin film coatings prepared from commercially available glycidoxypropyltrimethoxysilane (GPS) modified silica nanoparticles (SiNPs) (Bindzil® CC301 and Bindzil® CC302) have previously shown excellent antifouling performance against a broad range of microbes [Molino et al., "Hydration layer structure of biofouling-resistant nanoparticles," ACS Nano 12, 11610 (2018)]. In this work, single cell force spectroscopy (SCFS) was used to measure the biological interactions between Epicoccum nigrum fungal spores and the same silica nanoparticle-based surfaces used in the aforementioned study, including a: glass coverslip, unmodified SiNP coatings, and both low (Bindzil® CC301) and high density (CC302) GPS functionalized SiNP coatings as a function of NaCl concentration. From the SCFS curves, the spore adhesion to the surface was greatest on the glass coverslip (20-80 nN) followed by the unmodified SiNP (3-5 nN) across all salt concentrations. Upon approach to both surfaces, the spores showed a long-range attraction generally with a profile characteristic of biointeractions and likely those of the outer cell wall structures or biological constituents. The attractive force allowed the spores to initially adhere to the surface and was found to be linearly proportional to the spore adhesion. In comparison, both high and low density GPS-SINP significantly reduced the spore adhesion (0.5-0.9 nN). In addition, the spore adhesion on high density GPS-SiNP occurred in only 14%-27% of SCFS curves (40%-48% for low density GPS-SiNP) compared to 83%-97% for the unmodified SiNP, indicating that in most cases the GPS functionalization completely prevented spore adhesion. The GPS-SiNP surfaces conversely showed a long-range electrostatic repulsion at low 1mM NaCl that was replaced by short-range repulsion at the higher salt concentrations. From the findings, it is proposed that the attractive force is a critical step in initial adhesion processes of the spore. The effective antifouling properties of the GPS are attributed to the ability to negate the attractive forces, either through electrostatic repulsion in low salt conditions and primarily from short-range repulsion correlating to the previously reported combined steric-hydration effect of the GPS functionalization on SiNP coatings.

Involvement of UDP-glucose pyrophosphorylase from Verticillium dahliae in cell morphogenesis, stress responses, and host infection.

UDP-glucose pyrophosphorylase (UGP, EC 2.7.7.9) is an essential enzyme involved in carbohydrate metabolism. In Saccharomyces cerevisiae and other fungi, the UGP gene is indispensable for normal cell development, polysaccharide synthesis, and stress response. However, the function of the UGP homolog in plant pathogenic fungi has been rarely explored during pathogenesis. In this study, we characterize a UGP homolog named VdUGP from Verticillium dahliae, a soil-borne fungus that causes plant vascular wilt. In comparison with wild-type strain V07DF2 and complementation strains, the VdUGP knocked down mutant 24C9 exhibited sensitivity to sodium dodecyl sulfate (perturbing membrane integrity) and high sodium chloride concentration (high osmotic pressure stress). More than 25 % of the conidia of the mutant developed into short and swollen hypha and formed hyperbranching and compact colonies. The mutant exhibited decreased virulence on cotton and tobacco seedlings. Further investigation determined that the germination of the mutant spores was significantly delayed compared with the wild-type strain on the host roots. RNA-seq analysis revealed that a considerable number of genes encoding secreted proteins and carbohydrate-active enzymes were significantly downregulated in the mutant at an early stage of infection compared with those of the wild-type strain. RNA-seq data indicated that mutation affected many Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways both in the pathogen and in the inoculated plants at the infection stage. These alterations of the mutant in cultural phenotypes, virulence, and gene expression profiles clearly indicated that VdUGP played important roles in fungal cell morphogenesis, stress responses, and host infection.

Identification and Characterization of Verticillium longisporum Lineage A1/D1 from Brassica Crops in Manitoba, Canada.

Verticillium stripe in canola (Brassica napus L.) caused by Verticillium longisporum was first reported in Manitoba in 2014. In this study, Brassica crops including canola, mustard (Brassica juncea) and radish (Raphanus sativus) with visible symptoms of Verticillium stripe were collected from Portage La Prairie, Manitoba, and the pathogens were isolated. Isolates from canola and radish were identified to V. longisporum, which produced longer conidia (7.92-12.00 µm) than Verticillium dahliae (4.32-7.04 µm). An isolate derived from mustard was characterized as V. dahliae. Molecular diagnostics with 18S rDNA, 5.8S rDNA and mating-type marker primers were used to confirm the identification of Verticillium isolates. PCR-RFLP of the mitochondrial small subunit rDNA and the cytochrome b gene were also employed to distinguish V. longisporum isolates from V. dahliae. The multi-gene characterization approach allowed for lineage determination, and V. longisporum isolates from canola and radish were in the A1/D1 group. Isolates of Verticillium longisporum from canola inoculated onto the canola cultivar 'Westar' caused symptoms of stem striping, stunting and short plants. Re-isolated fungal strains from infected stems were again inoculated onto canola plants, in order to confirm that V. longisporum was the causal agent of Verticillium stripe disease in the pathogenicity test.

New species of Laboulbenia (Laboulbeniales, Ascomycota) on Gerridae (Hemiptera, Insecta), a new host family.

Four new species of Laboulbenia (Laboulbeniales, Ascomycota) occurring on Gerridae (Hemiptera, Insecta), a new host family, are described from six Central and South American countries: Bolivia, Brazil, Ecuador, Panama, Peru, and Venezuela. The new species are Laboulbenia brachymetrae, L. cylindrostethi, L. neogerris, and L. tachygerris.

Diaporthe species associated with twig blight and dieback of Vaccinium corymbosum in Portugal, with description of four new species.

Blueberry, an increasingly cultivated fruit crop in Portugal, is known to be susceptible to twig blight and dieback caused by species of Diaporthe. The diversity of Diaporthe species associated with symptomatic and asymptomatic Vaccinium corymbosum plants in Portugal was assessed. A multilocus sequence analysis of the rDNA internal transcribed spacer (ITS) region and the translation elongation factor 1-alpha (tef1-α), ß-tubulin (tub2), calmodulin (cal), and histone 3 (his3) genes revealed the presence of Diaporthe foeniculina, Diaporthe rudis, and four new species, which are described as Diaporthe crousii, Diaporthe phillipsii, Diaporthe rossmaniae, and Diaporthe vacuae. These new species were characterized in terms of their morphology, mating strategies, and temperature growth requirements. In artificial inoculation trials of V. corymbosum cv. Bluecrop plants, all Diaporthe species caused minor symptoms. Further, no differences in aggressiveness were apparent between species. This study provides the first survey of Diaporthe species associated with blueberry twig blight and dieback in Portugal. It disclosed the occurrence of a diverse assemblage of Diaporthe species, whose status and impact as pathogens of blueberry is not yet fully understood.

Genome-wide evolution of wobble base-pairing nucleotides of branchpoint motifs with increasing organismal complexity.

How have the branchpoint motifs evolved in organisms of different complexity? Here we identified and examined the consensus motifs (R1C2T3R4A5Y6, R: A or G, Y: C or T) of 898 fungal genomes. In Ascomycota unicellular yeasts, the G4/A4 ratio is mostly (98%) below 0.125 but increases sharply in multicellular species by about 40 times on average, and in the more complex Basidiomycota, it increases further by about 7 times. The global G4 increase is consistent with A4 to G4 transitions in evolution. Of the G4/A4-interacting amino acids of the branchpoint binding protein MSL5 (SF1) and the HSH155 (SF3B1), as well as the 5' splice sites (SS) and U2 snRNA genes, the 5' SS G3/A3 co-vary with the G4 to some extent. However, corresponding increase of the G4-complementary GCAGTA-U2 gene is rare, suggesting wobble-base pairing between the G4-containing branchpoint motif and GTAGTA-U2 in most of these species. Interestingly, the G4/A4 ratio correlates well with the abundance of alternative splicing in the two phyla, and G4 enriched significantly at the alternative 3' SS of genes in RNA metabolism, kinases and membrane proteins. Similar wobble nucleotides also enriched at the 3' SS of multicellular fungi with only thousands of protein-coding genes. Thus, branchpoint motifs have evolved U2-complementarity in unicellular Ascomycota yeasts, but have gradually gained more wobble base-pairing nucleotides in fungi of higher complexity, likely to destabilize branchpoint motif-U2 interaction and/or branchpoint A protrusion for alternative splicing. This implies an important role of relaxing the branchpoint signals in the multicellularity and further complexity of fungi.

Magnaporthiopsis cynodontis, a novel turfgrass pathogen with widespread distribution in the United States.

The genus Magnaporthiopsis of Magnaporthaceae (Magnaporthales, Sordariomycetes, Ascomycota) contains species that are predominantly necrotrophic pathogens, often producing simple hyphopodia and dark, ectotrophic runner hyphae on plant roots and stems during colonization. Fungal isolates from turfgrass roots with dark and ectotrophic runner hyphae were examined and identified based on morphological, biological, and phylogenetic analyses. Maximum likelihood and Bayesian methods were implemented to obtain phylogenetic trees for partial sequences of the 18S nuc rDNA, ITS1-5.8S-ITS2 nuc rDNA internal transcribed spacer, and 28S nuc rDNA regions, and of the minichromosome maintenance complex 7 (MCM7), largest subunit of RNA polymerase II (RPB1), and translation elongation factor 1-alpha (TEF1) genes. Our isolates consistently formed a distinct and highly supported clade within Magnaporthiopsis. These findings were reinforced by common and distinctive biological and morphological characters. Additionally, we conducted pathogenicity evaluations and demonstrated the ability of this fungus to colonize roots of ultradwarf bermudagrass, one of its native hosts, via ectotrophic, dark runner hyphae, causing disease symptoms including root discoloration and reduced root and shoot mass. Altogether, our discoveries enabled recognition and description of a new species, Magnaporthiopsis cynodontis, which has widespread distribution in the United States.