Pleoardoris graminearum, gen. et sp. nov., a new member of Pleosporales from North American Plains, its biogeography and effects on a foundation grass species.

Diverse fungi colonize plant roots worldwide and include species from many orders of the phylum Ascomycota. These fungi include taxa with dark septate hyphae that colonize grass roots and may modulate plant responses to stress. We describe a novel group of fungal isolates and evaluate their effects on the grass Bouteloua gracilis in vitro. We isolated fungi from roots of six native grasses from 24 sites spanning replicated latitudinal gradients in the south-central US grasslands and characterized isolates phylogenetically using a genome analysis. We analyzed 14 isolates representing a novel clade within the family Montagnulaceae (order Pleosporales), here typified as Pleoardoris graminearum, closely related to the genera Didymocrea and Bimuria. This novel species produces asexual, light brown pycnidium-like conidioma, hyaline hyphae, and chlamydospores when cultured on quinoa and kiwicha agar. To evaluate its effects on B. gracilis, seeds were inoculated with one of three isolates (DS304, DS334, and DS1613) and incubated at 25 C for 20 d. We also tested the effect of volatile organic compounds (VOCs) produced by the same isolates on B. gracilis root and stem lengths. Isolates had variable effects on plant growth. One isolate increased B. gracilis root length up to 34% compared with uninoculated controls. VOCs produced by two isolates increased root and stem lengths (P < 0.05) compared with controls. Internal transcribed spacer ITS2 metabarcode data revealed that P. graminearum is distributed across a wide range of sites in North America (22 of 24 sites sampled), and its relative abundance is influenced by host species identity and latitude. Host species identity and site were the most important factors determining P. graminearum relative abundance in drought experiments at the Extreme Drought in the Grasslands Experiment (EDGE) sites. Variable responses of B. gracilis to inoculation highlight the potential importance of nonmycorrhizal root-associated fungi on plant survival in arid ecosystems.

Darksidea phi, sp. nov., a dark septate root-associated fungus in foundation grasses in North American Great Plains.

Darksidea is a common genus of dark septate fungi-a group of ascomycetes in semiarid regions. A survey reported D. alpha and a distinct Darksidea lineage as abundant root-associated fungi of foundational grasses in North America. Fungi were isolated, and metabarcode data were obtained from sequencing of fungal communities of grass roots in the United States. During a comprehensive investigation of the Darksidea lineage, we carried out polyphasic taxonomy, genomic characterization, and identification of host associations, geographic distribution, and environmental factors that correlate with its abundance. For molecular phylogenetic studies, seven loci were sequenced. Isolates of the distinct Darksidea had variable colony morphology. No sexual reproductive structures were detected, but chlamydospores were frequently observed. The complete genome of an isolate of the lineage was sequenced with a size of 52.3 Mb including 14 707 gene models. Based on morphology and phylogenetic analysis, we propose the novel species Darksidea phi, sp. nov. Metabarcoding data showed that D. phi distribution and relative abundance were not limited to semiarid regions or a specific grass species, suggesting low host specificity among graminoids. This new species, D. phi, expands the distribution of the genus in the United States beyond prior reports from arid regions.

Seasonal variation and potential roles of dark septate fungi in an arid grassland.

High temperatures and extended drought in temperate and tropical arid ecosystems promote the colonization of diverse microenvironments by dark septate fungi (DSF). These fungi contribute to soil nutrient cycling, soil stabilization, and plant survival, but the roles of individual DSF species, their distributions, and their community diversity are poorly understood. The objective of this study was to evaluate the distribution, seasonal variation, and potential roles of DSF on plant growth. We collected biocrust (lichen-, moss-, and cyanobacterium-dominated biocrusts) soils at different depths and rhizosphere soils from two grasses, Bromus tectorum and Pleuraphis jamesii, in an arid grassland near Moab, Utah, USA. Seasonal variation of DSF was evaluated using culture-based approaches and compared with fungal community profiles from next-generation sequencing (NGS). Culturing showed that DSF were 30% more abundant in biocrusts compared with the focal rhizospheres. The abundance of DSF varied seasonally in belowground samples (rhizosphere and below-biocrust), with a significant increase during the summer months. Pleosporales was the dominant order (35%) in both biocrust and rhizosphere soils out of 817 isolated fungi. Dominant DSF genera in culture included Alternaria, Preussia, Cladosporium, Phoma, and an unknown Pleosporales. Similar results were observed in biocrust and rhizosphere soils NGS. Further, seed germination experiments using dominant taxa were conducted to determine their potential roles on germination and seedling growth using maize as a model plant. Cladosporium and unknown Pleosporales isolates showed plant growth-promoting ability. The variation in abundance of DSF, their differential occurrence in different microenvironments, and their ability to grow in a xerotolerant medium reflect adaptations to summer environmental conditions and to changes in the abundance of organic matter, as well as a potential increase in plant investment in these fungi when heat and drought stresses are more severe.

Draft Genome Sequence of Fusarium sp. Strain DS 682, a Novel Fungal Isolate from the Grass Rhizosphere.

The novel fungal strain, Fusarium sp. strain DS 682, was isolated from the rhizosphere of the perennial grass, Bouteloua gracilis, at the Konza Prairie Biological Station in Kansas. This fungal strain is common across North American grasslands and is resilient to environmental fluctuations. The draft genome is estimated to be 97.2% complete.

Improving Instructional Fitness Requires Change.

Transmission of information has benefitted from a breathtaking level of innovation and change over the past 20 years; however, instructional methods within colleges and universities have been slow to change. In the article, we present a novel framework to structure conversations that encourage innovation, change, and improvement in our system of higher education, in general, and our system of biology education, specifically. In particular, we propose that a conceptual model based on evolutionary landscapes in which fitness is replaced by educational effectiveness would encourage educational improvement by helping to visualize the multidimensional nature of education and learning, acknowledge the complexity and dynamism of the educational landscape, encourage collaboration, and stimulate experimental thinking about how new approaches and methodology could take various fields associated with learning, to more universal fitness optima. The framework also would encourage development and implementation of new techniques and persistence through less efficient or effective valleys of death.

Streptomyces buecherae sp. nov., an actinomycete isolated from multiple bat species.

A putative novel clade within the genus Streptomyces was discovered following antifungal screening against Pseudogymnoascus destructans, the causative agent of white-nose syndrome, and described using multi-locus sequencing analysis. Swabs from both the cave myotis bat (Myotis velifer) and the Brazilian free-tailed bat (Tadarida brasiliensis) in southern New Mexico bore isolates AC536, AC541T and AC563, which were characterised using phylogenetic, morphological, and phenotypic analyses. Multi-locus sequence analysis positions AC541T with neighbors Streptomyces rubidus (NRRL B-24619T), Streptomyces guanduensis (NRRL B-24617T), and Streptomyces yeochonensis (NRRL B-24245T). A complete genome of the type strain was assembled to determine its taxonomy and secondary metabolite potential. ANI comparisons between all closely related types strains are shown to be well below the 95-96% species delineation. DNA-DNA relatedness between AC541T and its nearest neighbors ranged between 23.7 and 24.1% confirming novelty. Approximately 1.49 Mb or 17.76% of the whole genome is devoted to natural product biosynthesis. The DNA G + C content of the genomic DNA of the type strain is 73.13 mol %. Micromorphology depicts ovoid spores with smooth surfaces in flexuous chains. Strains presented an ivory to yellow hue on most ISP media except inorganic salts-starch agar (ISP4) and can grow on D-glucose, mannitol, and D-fructose, but exhibited little to no growth on L-arabinose, sucrose, D-xylose, inositol, L-rhamnose, D-raffinose, and cellulose. This clade possesses the capability to grow from 10 to 45 °C and 12.5% (w/v) NaCl. There was strain growth variation in pH, but all isolates thrive at alkaline levels. Based on our polyphasic study of AC541T, the strain warrants the assignment to a novel species, for which the name Streptomyces buecherae sp. nov. is proposed. The type strain is AC541T (= JCM 34263T, = ATCC TSD201T).

Keratinophilic fungi: Specialized fungal communities in a desert ecosystem identified using cultured-based and Illumina sequencing approaches.

Soil fungi in desert ecosystems are adapted to harsh environmental conditions such as high soil surface temperatures and limited organic matter and water. Given limited carbon inputs from plant material, heterotrophic fungi likely use unconventional sources of carbon in these systems. A baiting method was used to culture keratinophilic fungi from biocrust and rhizosphere soils in an arid grassland in Utah, USA. Fungi were baited using llama and sheep wool, horsehair, and snakeskin on two media, and pure cultures were identified using ITS and LSU rRNA sequences. One hundred-eighteen fungal colonies were grown, representing a total of 32 Operational Taxonomic Units (OTUs) at 97 % similarity. Cultures were dominated by the phylum Ascomycota (88 %) followed by Mucoromycota (8.6 %) and Basidiomycota (3.4 %). The orders Pleosporales, Eurotiales, Hypocreales, and Sordariales were commonly isolated, with the dominant taxa Alternaria (27 %), Aspergillus (22 %), Fusarium (11 %), and Chaetomium (8%). Thirty percent of the fungi isolated have the capacity to degrade keratin in vitro using a keratin azure assay, with Penicillium showing the highest degradation followed by Geomyces, Alternaria, and Fusarium. Although keratin degraders can be infectious, dermatophytes associated with skin infections were not isolated in culture or detected in Illumina sequencing. Illumina sequencing was used to determine general patterns in seasonal variation and habitat preference of keratinophiles. Alternaria was the most abundant genus with >70 % of the sequences. The combination of Illumina data with culture-dependent approaches facilitated the characterization of a specialized community and confirmed the low abundance of dermatophytes in this arid site.

Genomes and secretomes of Ascomycota fungi reveal diverse functions in plant biomass decomposition and pathogenesis.

BACKGROUND: The dominant fungi in arid grasslands and shrublands are members of the Ascomycota phylum. Ascomycota fungi are important drivers in carbon and nitrogen cycling in arid ecosystems. These fungi play roles in soil stability, plant biomass decomposition, and endophytic interactions with plants. They may also form symbiotic associations with biocrust components or be latent saprotrophs or pathogens that live on plant tissues. However, their functional potential in arid soils, where organic matter, nutrients and water are very low or only periodically available, is poorly characterized. RESULTS: Five Ascomycota fungi were isolated from different soil crust microhabitats and rhizosphere soils around the native bunchgrass Pleuraphis jamesii in an arid grassland near Moab, UT, USA. Putative genera were Coniochaeta, isolated from lichen biocrust, Embellisia from cyanobacteria biocrust, Chaetomium from below lichen biocrust, Phoma from a moss microhabitat, and Aspergillus from the soil. The fungi were grown in replicate cultures on different carbon sources (chitin, native bunchgrass or pine wood) relevant to plant biomass and soil carbon sources. Secretomes produced by the fungi on each substrate were characterized. Results demonstrate that these fungi likely interact with primary producers (biocrust or plants) by secreting a wide range of proteins that facilitate symbiotic associations. Each of the fungal isolates secreted enzymes that degrade plant biomass, small secreted effector proteins, and proteins involved in either beneficial plant interactions or virulence. Aspergillus and Phoma expressed more plant biomass degrading enzymes when grown in grass- and pine-containing cultures than in chitin. Coniochaeta and Embellisia expressed similar numbers of these enzymes under all conditions, while Chaetomium secreted more of these enzymes in grass-containing cultures. CONCLUSIONS: This study of Ascomycota genomes and secretomes provides important insights about the lifestyles and the roles that Ascomycota fungi likely play in arid grassland, ecosystems. However, the exact nature of those interactions, whether any or all of the isolates are true endophytes, latent saprotrophs or opportunistic phytopathogens, will be the topic of future studies.

Presence and distribution of insect-associated and entomopathogenic fungi in a temperate pine forest soil: An integrated approach.

For decades entomopathogenic fungi have garnered interest as possible alternatives to chemical pesticides. However, their ecology outside of agroecosystems demands further study. We assessed the diversity and abundance of entomopathogenic and insect-associated fungi at a loblolly pine forest in North Carolina, USA using culture-dependent and next-generation sequencing libraries. Fungi were isolated using Galleriamellonella larvae, as well as from soil dilutions plated on a selective medium. Isolates were identified using Sanger sequencing of the ITS and LSU rRNA gene regions, and represented 36 OTUs including Metarhizium, Lecanicillium, and Paecilomyces. Additionally, we assessed the chitinolytic potential of isolates and found widespread, variable ability to degrade chitin within and between genera. Phylogenetic analyses resolved several isolates to genus, with some forming clades with other insect-associated taxa, as well as with fungi associated with plant tissues. Saprophytes were widely distributed in soil, while entomopathogens were less abundant and present primarily in the top two cm of the soil. The similarity between culture-dependent and next-generation sequencing results demonstrates that both methods can be used concurrently in this system to study the ecology of entomopathogenic fungi.

Diversity of thermophilic and thermotolerant fungi in corn grain.

Corn bins in the midwestern United States can reach temperatures up to 52 C. High temperatures combined with sufficient moisture and humidity in bins provide the perfect environment to promote the growth of thermophilic and thermotolerant fungi. In this article, we characterize for the first time thermophilic and thermotolerant fungi in corn grain bins using culture-based methods and pyrosequencing techniques. Corn samples were collected from local farms in western Illinois. Samples were plated and incubated at 50 C using a variety of approaches. Of several hundred kernels examined, more than 90% showed colonization. Species identified using culture methods included Thermomyces lanuginosus, Thermomyces dupontii, Aspergillus fumigatus, Thermoascus crustaceus, and Rhizomucor pusillus. Pyrosequencing was also performed directly on corn grain using fungal-specific primers to determine whether thermophilic fungi could be detected using this technique. Sequences were dominated by pathogenic fungi, and thermophiles were represented by less than 2% of the sequences despite being isolated from 90% of the grain samples using culturing techniques. The high abundance of previously undocumented viable fungi in corn could have negative implications for grain quality and pose a potential risk for workers and consumers of corn-derived products in the food industry. Members of the Sordariales were absent among thermophile isolates and were not represented in nuc rDNA internal transcribed spacer (ITS) sequences. This is in striking contrast with results obtained with other substrates such as litter, dung, and soils, where mesophilic and thermophilic members of the Sordariaceae and Chaetomiaceae are common. This absence appears to reflect an important difference between the ecology of Sordariales and other orders within the Ascomycota in terms of their ability to compete in microhabitats rich in sugars and living tissues.

Streptomyces corynorhini sp. nov., isolated from Townsend's big-eared bats (Corynorhinus townsendii).

Four bacterial strains, with the capability of inhibiting Pseudogymnoascus destructans, the causative agent of white-nose syndrome, were isolated from male Townsend's big-eared bats (Corynorhinus townsendii, Family: Vespertilionidae) in New Mexico. Isolates AC161, AC162, AC208, and AC230T were characterised as a novel clade using morphological, phenotypic and phylogenetic analysis. A draft genome of the type strain was completed to determine its taxonomy and secondary metabolite biosynthetic potential. Multi-locus sequence analysis nests AC230T with neighbours Streptomyces scopuliridis (NRRL B-24574T), Streptomyces lushanensis (NRRL B-24994T), Streptomyces odonnellii (NRRL B-24891T) and Streptomyces niveus (NRRL 2466T). Further phylogenetic analysis showed the MLSA distances between AC230T and its near neighbours are much greater than the generally accepted threshold (> 0.007) for bacterial species delineation. DNA-DNA relatedness between AC230T and its near neighbours ranged between 25.7 ± 2.1 and 29.9 ± 2.4%. The DNA G+C content of the genomic DNA of the type strain is 71.7 mol%. Isolate AC230T presents a white to ivory hue on most ISP media and its micromorphology exhibits ovoid spores with smooth surfaces in flexuous chains. Based on our study of AC230T, the strain warrants the assignment to a novel species, for which the name Streptomyces corynorhini sp. nov. is proposed. The type strain is AC230T (= JCM 33171T, = ATCC TSD155T).

Microscopic characterization of orchid mycorrhizal fungi: Scleroderma as a putative novel orchid mycorrhizal fungus of Vanilla in different crop systems.

Vanilla is an orchid of economic importance widely cultivated in tropical regions and native to Mexico. We sampled three species of Vanilla (V. planifolia, V. pompona, and V. insignis) in different crop systems. We studied the effect of crop system on the abundance, type of fungi, and quality of pelotons found in the roots using light and electron microscopy and direct sequencing of mycorrhizal structures. Fungi were identified directly from pelotons obtained from terrestrial roots of vanilla plants in the flowering stage. Root samples were collected from plants in crop systems located in the Totonacapan area in Mexico (states of Puebla and Veracruz). DNA was extracted directly from 40 pelotons and amplified using ITS rRNA sequencing. Peloton-like structures were observed, presenting a combination of active pelotons characterized by abundant hyphal coils and pelotons in various stages of degradation. The most active pelotons were observed in crop systems throughout living tutors (host tree) in comparison with roots collected from dead or artificial tutors. Fungi identified directly from pelotons included Scleroderma areolatum, a common ectomycorrhizal fungus that has not been reported as a mycorrhizal symbiont in orchids. Direct amplification of pelotons also yielded common plant pathogens, including Fusarium and Pyrenophora seminiperda, especially in those sites with low colonization rates, and where large numbers of degraded pelotons were observed. This research reports for the first time the potential colonization of Vanilla by Scleroderma, as a putative orchid mycorrhizal symbiont in four sites in Mexico and the influence of crop system on mycorrhizal colonization on this orchid.

Skin and fur bacterial diversity and community structure on American southwestern bats: effects of habitat, geography and bat traits.

Microorganisms that reside on and in mammals, such as bats, have the potential to influence their host's health and to provide defenses against invading pathogens. However, we have little understanding of the skin and fur bacterial microbiota on bats, or factors that influence the structure of these communities. The southwestern United States offers excellent sites for the study of external bat bacterial microbiota due to the diversity of bat species, the variety of abiotic and biotic factors that may govern bat bacterial microbiota communities, and the lack of the newly emergent fungal disease in bats, white-nose syndrome (WNS), in the southwest. To test these variables, we used 16S rRNA gene 454 pyrosequencing from swabs of external skin and fur surfaces from 163 bats from 13 species sampled from southeastern New Mexico to northwestern Arizona. Community similarity patterns, random forest models, and generalized linear mixed-effects models show that factors such as location (e.g., cave-caught versus surface-netted) and ecoregion are major contributors to the structure of bacterial communities on bats. Bats caught in caves had a distinct microbial community compared to those that were netted on the surface. Our results provide a first insight into the distribution of skin and fur bat bacteria in the WNS-free environment of New Mexico and Arizona. More importantly, it provides a baseline of bat external microbiota that can be explored for potential natural defenses against pathogens.

Bifiguratus adelaidae, gen. et sp. nov., a new member of Mucoromycotina in endophytic and soil-dwelling habitats.

Illumina amplicon sequencing of soil in a temperate pine forest in the southeastern United States detected an abundant, nitrogen (N)-responsive fungal genotype of unknown phylogenetic affiliation. Two isolates with ribosomal sequences consistent with that genotype were subsequently obtained. Examination of records in GenBank revealed that a genetically similar fungus had been isolated previously as an endophyte of moss in a pine forest in the southwestern United States. The three isolates were characterized using morphological, genomic, and multilocus molecular data (18S, internal transcribed spacer [ITS], and 28S rRNA sequences). Phylogenetic and maximum likelihood phylogenomic reconstructions revealed that the taxon represents a novel lineage in Mucoromycotina, only preceded by Calcarisporiella, the earliest diverging lineage in the subphylum. Sequences for the novel taxon are frequently detected in environmental sequencing studies, and it is currently part of UNITE's dynamic list of most wanted fungi. The fungus is dimorphic, grows best at room temperature, and is associated with a wide variety of bacteria. Here, a new monotypic genus, Bifiguratus, is proposed, typified by Bifiguratus adelaidae.

Western Bats as a Reservoir of Novel Streptomyces Species with Antifungal Activity.

At least two-thirds of commercial antibiotics today are derived from Actinobacteria, more specifically from the genus Streptomyces Antibiotic resistance and new emerging diseases pose great challenges in the field of microbiology. Cave systems, in which actinobacteria are ubiquitous and abundant, represent new opportunities for the discovery of novel bacterial species and the study of their interactions with emergent pathogens. White-nose syndrome is an invasive bat disease caused by the fungus Pseudogymnoascus destructans, which has killed more than six million bats in the last 7 years. In this study, we isolated naturally occurring actinobacteria from white-nose syndrome (WNS)-free bats from five cave systems and surface locations in the vicinity in New Mexico and Arizona, USA. We sequenced the 16S rRNA region and tested 632 isolates from 12 different bat species using a bilayer plate method to evaluate antifungal activity. Thirty-six actinobacteria inhibited or stopped the growth of P. destructans, with 32 (88.9%) actinobacteria belonging to the genus Streptomyces Isolates in the genera Rhodococcus, Streptosporangium, Luteipulveratus, and Nocardiopsis also showed inhibition. Twenty-five of the isolates with antifungal activity against P. destructans represent 15 novel Streptomyces spp. based on multilocus sequence analysis. Our results suggest that bats in western North America caves possess novel bacterial microbiota with the potential to inhibit P. destructansIMPORTANCE This study reports the largest collection of actinobacteria from bats with activity against Pseudogymnoascus destructans, the fungal causative agent of white-nose syndrome. Using multigene analysis, we discovered 15 potential novel species. This research demonstrates that bats and caves may serve as a rich reservoir for novel Streptomyces species with antimicrobial bioactive compounds.

Sequence-based classification and identification of Fungi.

Fungal taxonomy and ecology have been revolutionized by the application of molecular methods and both have increasing connections to genomics and functional biology. However, data streams from traditional specimen- and culture-based systematics are not yet fully integrated with those from metagenomic and metatranscriptomic studies, which limits understanding of the taxonomic diversity and metabolic properties of fungal communities. This article reviews current resources, needs, and opportunities for sequence-based classification and identification (SBCI) in fungi as well as related efforts in prokaryotes. To realize the full potential of fungal SBCI it will be necessary to make advances in multiple areas. Improvements in sequencing methods, including long-read and single-cell technologies, will empower fungal molecular ecologists to look beyond ITS and current shotgun metagenomics approaches. Data quality and accessibility will be enhanced by attention to data and metadata standards and rigorous enforcement of policies for deposition of data and workflows. Taxonomic communities will need to develop best practices for molecular characterization in their focal clades, while also contributing to globally useful datasets including ITS. Changes to nomenclatural rules are needed to enable validPUBLICation of sequence-based taxon descriptions. Finally, cultural shifts are necessary to promote adoption of SBCI and to accord professional credit to individuals who contribute to community resources.

Ribosomal RNA gene detection and targeted culture of novel nitrogen-responsive fungal taxa from temperate pine forest soil.

Soil fungal communities are responsible for carbon and nitrogen (N) cycling. The high complexity of the soil fungal community and the high proportion of taxonomically unidentifiable sequences confound ecological interpretations in field studies because physiological information is lacking for many organisms known only by their rRNA sequences. This situation forces experimental comparisons to be made at broader taxonomic racks where functions become difficult to infer. The objective of this study was to determine OTU (operational taxonomic units) level responses of the soil fungal community to N enrichment in a temperate pine forest experiment and to use the sequencing data to guide culture efforts of novel N-responsive fungal taxa. Replicate samples from four soil horizons (up to 10 cm depth) were obtained from ambient, enriched CO2 and N-fertilization plots. Through a fungal large subunit rRNA gene (LSU) sequencing survey, we identified two novel fungal clades that were abundant in our soil sampling (representing up to 27% of the sequences in some samples) and responsive to changes in soil N. The two N-responsive taxa with no predicted taxonomic association were targeted for isolation and culturing from specific soil samples where their sequences were abundant. Representatives of both OTUs were successfully cultured using a filtration approach. One taxon (OTU6) was most closely related to Saccharomycotina; the second taxon (OTU69) was most closely related to Mucoromycotina. Both taxa likely represent novel species. This study shows how observation of specific OTUs level responses to altered N status in a large rRNA gene field survey provided the impetus to design targeted culture approaches for isolation of novel N-responsive fungal taxa.

Fungal identification using a Bayesian classifier and the Warcup training set of internal transcribed spacer sequences.

Fungi are key organisms in many ecological processes and communities. Rapid and low cost surveys of the fungal members of a community can be undertaken by isolating and sequencing a taxonomically informative genomic region, such as the ITS (internal transcribed spacer), from DNA extracted from a metagenomic sample, and then classifying these sequences to determine which organisms are present. This paper announces the availability of the Warcup ITS training set and shows how it can be used with the Ribosomal Database Project (RDP) Bayesian Classifier to rapidly and accurately identify fungi using ITS sequences. The classifications can be down to species level and use conventional literature-based mycological nomenclature and taxonomic assignments.

Root-associated fungal community response to drought-associated changes in vegetation community.

Recent droughts in southwestern USA have led to large-scale mortality of piñon (Pinus edulis) in piñon-juniper woodlands. Piñon mortality alters soil moisture, nutrient and carbon availability, which could affect the root-associated fungal (RAF) communities and therefore the fitness of the remaining plants. We collected fine root samples at a piñon-juniper woodland and a juniper savannah site in central New Mexico. Roots were collected from piñon and juniper (Juniperus monosperma) trees whose nearest neighbors were live piñon, live juniper or dead piñon. RAF communities were analyzed by 454 pyrosequencing of the universal fungal ITS region. The most common taxa were Hypocreales and Chaetothyriales. More than 10% of ITS sequences could not be assigned taxonomy at the phylum level. Two of the unclassified OTUs significantly differed between savanna and woodland, had few like sequences in GenBank and formed new fungal clades with other unclassified RAF from arid plants, highlighting how little study has been done on the RAF of arid ecosystems. Plant host or neighbor did not affect RAF community composition. However, there was a significant difference between RAF communities from woodland vs. savanna, indicating that abiotic factors such as temperature and aridity might be more important in structuring these RAF communities than biotic factors such as plant host or neighbor identity. Ectomycorrhizal fungi (EM) were present in juniper as well as piñon in the woodland site, in contrast with previous research, but did not occur in juniper savanna, suggesting a potential shared EM network with juniper. RAF richness was lower in hosts that were neighbors of the opposite host. This may indicate competitive exclusion between fungi from different hosts. Characterizing these communities and their responses to environment and plant neighborhood is a step toward understanding the effects of drought on a biome that spans 19,000,000 ha of southwestern USA.

Phylogenetic Diversity of Sponge-Associated Fungi from the Caribbean and the Pacific of Panama and Their In Vitro Effect on Angiotensin and Endothelin Receptors.

Fungi occupy an important ecological niche in the marine environment, and marine fungi possess an immense biotechnological potential. This study documents the fungal diversity associated with 39 species of sponges and determines their potential to produce secondary metabolites capable of interacting with mammalian G-protein-coupled receptors involved in blood pressure regulation. Total genomic DNA was extracted from 563 representative fungal strains obtained from marine sponges collected by SCUBA from the Caribbean and the Pacific regions of Panama. A total of 194 operational taxonomic units were found with 58% represented by singletons based on the internal transcribed spacer (ITS) and partial large subunit (LSU) rDNA regions. Marine sponges were highly dominated by Ascomycota fungi (95.6%) and represented by two major classes, Sordariomycetes and Dothideomycetes. Rarefaction curves showed no saturation, indicating that further efforts are needed to reveal the entire diversity at this site. Several unique clades were found during phylogenetic analysis with the highest diversity of unique clades in the order Pleosporales. From the 65 cultures tested to determine their in vitro effect on angiotensin and endothelin receptors, the extracts of Fusarium sp. and Phoma sp. blocked the activation of these receptors by more than 50% of the control and seven others inhibited between 30 and 45%. Our results indicate that marine sponges from Panama are a "hot spot" of fungal diversity as well as a rich resource for capturing, cataloguing, and assessing the pharmacological potential of substances present in previously undiscovered fungi associated with marine sponges.