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FINAL PROGRAM
Middle-Atlantic States Mycology Conference (MASMC)
April 20, 2024
French Family Science Center (FFSC), Duke University
(124 Science Drive, Durham 27708)
abbreviated program (talks only, for printing)
Parking: Please carpool when possible. all-day parking passes are available for the gated Chemistry parking lot. email: fungi@duke.edu (before you leave town)
8:00-9:00 registration/check in (FFSC Atrium, 2nd floor)
breakfast/coffee
Posters: Please put up posters outside auditorium and around FFSC atrium area. Posters will be up all day (till 7). Presenters: please load your talks in FFSC auditorium before your session starts
9:00-10:30 session 1 (talks, abstracts 1-6)
10:30-11:00 coffee break, group photo (in front of FFSC)
11:00-12:30 session 2 (talks, abstracts 7-12)
12:30-2:30 lunch & poster session (abstracts 21-50).
note: poster boards are not numbered, spread around FFSC atrium.
2:30-5:00 session 3 (talks, abstracts 13-20).
4:30 MASMC Business Meeting
5:00-7:00 Happy hour with hor d’oevres
SUNDAY Morel Foray, April 21 8:30-noon. We will meet the Duke Forest Rigsbee Picnic Shelter gate F located off of state route 751. Parking on site is limited, please be careful if parking along the roadside, and carpool if possible.
Talks/Speaker Abstracts 1-20
- Amanda Chandler (Department of Ecology & Evolutionary Biology, University of Tennessee Knoxville), Jessica Allen (Department of Biology, Eastern Washington University), and P. Brandon Matheny (Department of Ecology & Evolutionary Biology, University of Tennessee Knoxville)Trait-based risk assessment of cyanolichens
Lichens represent a wealth of biodiversity. Intraspecific phenotypic plasticity in lichens continues to obscure our understanding of how ecological influences vary between species, communities, and abiotic factors. A consequence of this knowledge deficit is a lack of a clear understanding concerning functional and ecological traits that determine extinction risk for many species. A recent study found nearly 60% of the 168 lichen species researchers assessed for the International Union for Conservation of Nature (IUCN) Red List to fall under a threatened status. Lichens containing nitrogen-fixing cyanobacterial photobionts are thought to be more sensitive to environmental change than their green algal relatives, though it remains unclear which traits, if any, might make them more prone to extinction. A Few studies have started to tease out traits driving lichen rarity. Given these insights and that rare cyanolichens require more research, we propose to use a trait-based approach to determine if substrate, symbiont partner, reproductive mode, habitat type, elevation, and climate are indicative of risk in the monophyletic cyanolichen genus Peltigera. This genus is widespread in North America, making targeted field studies possible for taxa requiring additional data. Comprehensive assessments for all North American species will be synthesized and traits will be mapped phylogenetically to visualize if any might be predictors of cyanolichen risk. Use of a trait-focused methodology will elicit more quantitative ecological and evolutionary data to more efficiently address conservation-related questions. This work will add to the growing body of knowledge surrounding fungal ecology and conservation, as well as provide insight on drivers of cyanolichen risk and published IUCN Red List assessments for all North American species of Peltigera.
- Xuefei Chen1, Michael Hoy2, Diessel Duan3, Kalinka Koteva1, Michaela Spitzer1, Allison Guitor1, Emily Puumala4, Guanggan Hu6, Nicole Robbins4, Ray Truant5, James Kronstad6, Leah Cowen4, Huilin Li3, Joseph Heitman2, Gerard D. Wright1
1David Braley Centre for Antibiotics Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, L8S 4K1, Canada
2Department of Molecular Genetics and Microbiology, Duke University, Duke University Medical Center, Durham, NC 27710, USA.
3Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5G 1M1, Canada.
4Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5G 1M1, Canada.
5Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
6Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
Butyrolactol A is a novel phospholipid flippase inhibitor that potentiates the antifungal activity of caspofungin against intrinsically resistant Cryptococcus.
Cryptococcal infections are critical threats to human health, particularly for immune-compromised individuals. Treatment of these infections is challenging due to the limited therapeutic options available for fungi. Cryptococcus is intrinsically resistant to the most recently approved class of antifungal drugs, the echinocandins, which inhibit β-(l,3)-D-glucan synthase required for cell wall synthesis. The discovery of potentiators of caspofungin that sensitize Cryptococcus to echinocandins would be highly valuable in treating infections.
A high-throughput screen of >4000 natural product extracts was performed in the Wright Lab to identify potentiators of caspofungin against Cryptococcus, and a promising candidate, butyrolactol A (butA), was identified. To further investigate the compound, a high-yield butA production strain was created through heterologous expression of the biosynthetic gene cluster coupled with regulatory modification, increasing compound yield 10-fold compared to the wildtype strain. ButA-caspofungin synergy was then verified conserved across multiple fungal pathogens, including C. neoformans, C. gattii, and multidrug-resistant Candida auris. Furthermore, a robust in-vivo synergy of ButA treatment in combination with caspofungin has been demonstrated in the Galleria mellonella and Caenorhabditis elegans models. We next demonstrated that butA is an inhibitor of the Apt1-Cdc50 phospholipid flippase complex, giving rise to disrupted phospholipid asymmetry and impaired vesicle-mediated trafficking that contribute to increased caspofungin uptake and potency against Cryptococcus.
To further explore how butA binds to Apt1-Cdc50, a cryo-electron microscopy study for two different states of the P4-ATPase flippase complex was performed. Cryo-electron microscopy images of Apt1-Cdc50 in a butA-bound E2P state clearly show that butA shallowly binds to the substrate pocket of the holo flippase complex, which appears to block the entry site for substrate lipids, thus disrupting the essential phospholipid asymmetry of biological membranes. In conclusion, we identified an unknown mode of action of butA that effectively potentiates echinocandins in drug-resistant fungi pathogens, which shed some light on exploitation in antifungal drug development.
- Judith O. Enemudo*, Nathan Holt, Brandon G. Essick, Nkese S. Udombang, Melvin Mensah-Bonsu, Felicia N. Anike, Omon S. Isikhuemhen.
Mushroom Biology and Fungal Biotechnology Laboratory, Department of Natural Resources & Environmental Design, CAES, North Carolina A&T State University.Effect of oak leave supplementation on fruit body yield in Ganoderma mbrekobenum.
Ganoderma species are known to possess anti-tumor, anti-inflammatory, immune-modulatory, antioxidant and other biological traits which render it to be used as a health supplement. However, strains of African origin are not characterized and optimized for commercial cultivation. Also, forest leaves wastes are seldom used in mushrooms cultivation. G. mbrekobenum from Africa and oak leaves were tested in cultivation. Five different combinations of sawdust, oak leaves, and wheat bran (Treatments T1-5) were tested in the cultivation the study. T1 was a positive control which contained sawdust and wheat bran only. T2, T3, T4, T5 contained oak leaves 5, 10, 15 and 20% respectively. Wheat bran was constant at 10% in T2-5. Results indicated that T1 took 8 days to colonize, 14 days for pin heads formation, fruit body yield of 21.08±1.591 and biological efficiency (BE) 3.15 %. There were no significant differences from T1 in the aforesaid parameters obtained for T2. On the contrary, T3, T4, colonized the substrate on day 7, produce pin heads on day 12, fruiting body yield of 36.04±1.519 (BE 6.13%) and 36.02±1.549 (BE 5.73 %), respectively. Treatment T5 took longer days to colonize and fruit body yield of 29.00±0.70 (BE 4.61%). It appears that T3 and T4 which had 10 % and 15 % supplementation with oak leaves had the best yield among all the treatments tested. A pilot study for mass cultivation and yield optimization in G. mbrekobenum ongoing.
- Django Grootmyers1, D. Jean Lodge2, Timothy J. Baroni3, Claudio Angelini4,5, Daniel S. Newman6, Kerri McCabe7, Jacob Kalichman1, P. Brandon Matheny1
1Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee, USA, 2Department of Plant Pathology, Odum School of Ecology, University of Georgia, Athens, Georgia, USA, 3Department of Biological Sciences, State University of New York, College at Cortland, Cortland, New York, USA, 4Jardin Botanico Nacional Dr. Rafael Ma. Moscoso, Santo Domingo, Dominican Republic, 5Via Cappuccini, 78/8, 33170 Pordenone, Italy, 6New Orleans, Louisiana, USA, 7Arkansas Mycological Society, Saint Joe, Arkansas, USAWhat on earth is Lactocollybia?
Roger Heim described an odd, white, gilled mushroom from Madagascar producing latex much like species of Lactarius as Collybia lacrimosa. Rolf Singer moved this species to a novel genus, Lactocollybia. Singer transferred other previously described fungi to three new sections of Lactocollybia: sect. Albae, sect. Bertrandiella, and sect. Aurantiacae. He also established sect. Graminicolae for a novel species growing on bamboo. Species of Lactocollybia have been reported from all continents except Antarctica, and from a variety of habitats, although mostly tropical or subtropical. Unfortunately for those working on Lactocollybia, only species of sect. Albae have DNA sequences available in public sequence databases. The remaining sections of Lactocollybia are quite different from sect. Albae. The identity of Lactocollybia sensu stricto and the relationships of the remaining sections of Lactocollybia both to each other and to other fungi are unclear. To address these issues, we aimed to sequence herbarium collections and recent field collections of species representing all sections of Lactocollybia. We were able to successfully sequence representatives of all sections except sect. Lactocollybia. We find Lactocollybia sect. Albae to be close to Hemimycena and Mycenella in the Porotheleaceae and to be the most species rich sections of Lactocollybia. We find L. graminicola, the sole representative of sect. Graminicolae to be related to Gloiocephala and Rhizomarasmius in the Physalacriaceae. We find L. ianthina, the type and only species of sect. Bertrandiella as well as the type species of the genus Bertrandiella, to represent an annulate Hygrocybe closely related to H. roseopallida. The genus Bertrandiella is thus a junior synonym of Hygrocybe. We find sect. Aurantiaceae to represent a novel genus of collybioid gilled mushrooms in the Polyporales, and L. aurantiaca to represent a species complex distributed throughout the Americas. Singer’s Lactocollybia is heterogeneous and highly polyphyletic. Unfortunately, the holotype and only collection of C. lacrimosa has been lost, and the relationships of Lactocollybia sensu stricto will not be clear until this species is recollected from Madagascar.
- Andrii P. Gryganskyi, Victor Roman, Patrick B. Dennis, Blake W. Stamps, Melinda Ostendorf,
Kristen Bruce, Amber Braddock, Nancy Kelley-LoughnaneMycelia customizable structural materials
Wood-destroying fungi (Aphyllophorales, bracket, or polypore fungi) rapidly colonize and aggregate cellulose-containing substrates up to a plastic-like hardness, providing stable ablative coatings. We have identified three fungal species out of fifty various tested polypores: Ganoderma, Schizophyllum, and Trametes. Comparisons of the internal material structure produced by these fungi have shown a cohesive hyphal-substrate network, with hyphae (fungal filaments) filling structure gaps of up to 3-4 mm and forming a leather-like surface with good qualitative material strength. Initial thermogravimetric analysis has shown slower mass and water loss by the mycelium colonized compared to the other fungi or control substrates, both wet and semi-dry suggesting that these materials may make for an excellent ablative coating. It can be enhanced by binding other useful ablative components like silicate granules or carbon nanofibers, enabling a multi-layer structure with different physical characteristics. Identification of genetic mechanisms to control cell-wall structure will accelerate rapid modification of the mycelial matrix and enhance the inclusion of the non-organic materials into the living mycelia to produce bespoke properties (e.g., enhanced hardness, thermal conductivity, elasticity, radiation tolerance, etc.).
- Maria I. Higuita-Aguirre1,2, Clancy P. Larmour1, Benjamin D. Rose2, Christian Shaw1, Rytas Vilgalys3, Rachel L. Cook2, Kevin Garcia1
1Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
2Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
3Department of Biology, Duke University, Durham, NC 27708, USADesigning a synthetic community of ectomycorrhizal fungi for improving phosphorus uptake in Pinus taeda
Loblolly pine (Pinus taeda L.) is a crop tree with high economic value and native from the southeastern United States. In its native range, soils are usually low in phosphorus (P), making the use of P-based fertilizers a common practice in silviculture. Trees always associate with soil microbes that play an important role in mineral weathering and plant nutrient uptake, including P. In natural temperate and boreal biomes, as well as in managed plantations, ectomycorrhizal (ECM) fungi are major belowground components for these processes and intimately interact with the roots of loblolly pines. Through the development of extraradical hyphae that explore a large volume of soil, ECM fungi considerably improve nutrient absorption by colonized roots. Most work so far on P transport facilitated by ECM fungi focus on a single species, making this type of approach rather reductionist. In nature however, loblolly pines are colonized by dozens of different species of ECM fungi. Therefore, the individual effect generally observed in control conditions can be a part of a complex dynamic where interactions between more than one fungi are present. The purpose of this presented work is to design a simplified synthetic ECM community incorporating native fungal species associating with loblolly pine, and evaluate its effect on plant P uptake under limiting and sufficient conditions.
- Nathan Holt*1, Brandon G. Essick1, Melvin Mensah-Bonsu1, Felicia N. Anike1, Raga Krishnakumar2, Matthew Hirakawa2, Omon S. Isikhuemhen1.
Mushroom Biology and Fungal Biotechnology Laboratory, Department of Natural Resources & Environmental Design, CAES, North Carolina A&T State University, Sandia National Laboratories, Livermore, CA.
Domestication, Mating Behavior and Interspecies Compatibility between Pleurotus sp. From Africa and P. djamor.A Pleurotus species (P773) was discovered and collected from the wild in Africa. Its ITS region was sequenced, and its closest match in the GenBank (NCBI BLAST database) was found to be P. opuntiae, followed by P. djamor with sequence similarity levels (95.91 and 93.98%, respectively), which was insufficient to make a species identity call. To further characterize P773, we conducted mycelial growth studies to determine its temperature requirements. The optimal temperature for mycelial growth was observed at 30°C. Additionally, P773 was cultivated on a sawdust substrate, and fruiting bodies began to develop 35 days after inoculation. Mating studies, including intrastock and interspecies crosses with other Pleurotus species such as P. ostreatus, P. pulmonarius, P. eryngii, and P. djamor. Intraspecies crosses revealed a tetrapolar mating pattern, but no positive cross was obtained with other Pleurotus species tested, except P. djamor. However, the crosses between P773 and P. djamor indicated 93% compatibility, which suggests it to be same biological species with P. djamor. Interestingly, P773 initially exhibited a white color upon collection but developed a bluish-gray hue during cultivation, in contrast to the characteristic pink mushrooms produced by P. djamor. Fruiting body characteristics of interspecies mating progenies involving P773 and P. djamor is ongoing. The remarkable high-temperature tolerance of P773, coupled with its ability to successfully mate with a commercial strain of P. djamor, positions it as a promising candidate for the development of commercial strains suitable for cultivation in warmer climates worldwide. Moreover, its potential application in mitigating the effects of global warming and climate change warrants further exploration.
- Abigail Ireland, Stephanie Kivlin, Karen Hughes
Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USACharacterizing the unknown diversity of Pseudogymnoascus in North American bat hibernacula: description of 15 new taxa
Pseudogymnoascus, (Pseudeurotiaceae, Leotiomycetes), is a globally-distributed genus of saprophytic and dermatophytic fungi, the diversity of which has scarcely been explored. In light of the ecological and economic devastation caused by P. destructans (White-nose Syndrome), the need for further investigation of potentially pathogenic congeneric taxa is paramount. This study characterizes the diversity of the genus across three bat hibernacula in Pennsylvania. Additionally, fifteen new species and varieties are described from North American bat hibernacula using a polyphasic taxonomic approach. Phylogenetic analyses of the internal transcribed spacer of ribosomal nuclear DNA (ITS), the second largest subunit of RNA polymerase II (RPB2), and elongation factor 1-alpha (EF1A), along with morphological characteristics conclusively support these taxa as unique, expanding coverage of this genus by 50%. The inclusion of these taxa in diversity estimates and extrapolations suggests only 84.69% of Pseudogymnoascus diversity was captured in our sampling. While total diversity for the genus remains unknown, this study confirms that Pseudogymnoascus is widely distributed with many uncharacterized taxa. Furthermore, this work provides a springboard for future studies of the ecological functions and distribution of Pseudogymnoascus and allies.
- Darren Kirkendall1, Michelle Jusino2, Nicole Reynolds3, James Skelton1
1College of William and Mary, Biology Department, Williamsburg, VA, USA; 2USDA Forest Service, Northern Research Station, Center for Forest Mycology Research, Madison, WI; 3Cornell University, School of Integrative Plant Science, Ithaca, NY, USAWhat’s the scoop on the mycoloop? Fungal parasites associated with increased zooplankton density in Chesapeake Bay
Fungi are a little known but vital part of aquatic ecosystems. Aquatic fungi are commonly regarded as important decomposers that release nutrients from dead biomass, but a recent hypothesis – the mycoloop – proposes that they may also act as parasites on hard-to-eat algae and help release their nutrients to zooplankton and higher trophic levels. This interaction can form a significant energy source during algal blooms when zooplankton may otherwise starve. Most previous work studying the mycoloop has focused on freshwater lakes with some attention paid to marine environments. In this study we determine the effect that the mycoloop has on the abundance and community composition of zooplankton of the largest estuary in the United States, the Chesapeake Bay in Virginia and Maryland. Sampling was conducted over 3 months (June, July, August) in 2023 at 27 sites. We sampled zooplankton using traditional methods and collected environmental DNA which we amplified with fungal ITS and LSU primer sets to determine how zooplankton community composition and the surrounding fungal communities were related. To confirm that zooplankton were consuming aquatic fungi we assessed their gut contents using eDNA. We determined that the zooplankton and fungal communities varied both spatially and temporally. We found a significant relationship between fungi with the lifestyle “algal parasite” and the abundance of zooplankton. This study improves our understanding of the functional roles of fungi in estuarine systems and supports the importance of the mycoloop hypothesis in the lower food web of the Chesapeake Bay.
- Joel Kwon, Nathan Holt, Felicia N. Anike, Omon S. Isikhuemhen.
Mushroom Biology and Fungal Biotechnology Laboratory, Department of Natural Resources & Environmental Design, CAES, North Carolina A&T State University.
Spore Germination in wild and commercial strains of Pleurotus ostreatus.
Pleurotus ostreatus is distributed worldwide and is the second most cultivated mushroom globally. It plays a major ecological role in the forest ecosystem; it is a white rot, which participates in forest biomass degradation and recycling. Therefore, its reproduction biology is important to environmental conservation and breeding new strains for the mushroom industry. Scanty reports and discussions exist in the literature on spore germination in Pleurotus spp. Further, it is known that strains that have been stored for long periods of time undergo degeneration, which can affect expressions of the color of mycelium and fruit bodies, the vigor of growth, etc. However, it is not known whether this strain degeneration (common to varying degrees in commercial strains) affects the germination of spores. This study aims to determine the spore germination rates of commercial (MBFBL 67) and wild (MBFBL 400) strains of P. ostreatus at different temperatures. Spore prints from fruiting bodies of selected isolates were collected and used for the germination studies. Spores were diluted to 20, 100, 500, and 1000 per 100 uL and plated into a spore germination medium. Six replicate plates per dilution were incubated at 15°C, 20°C, 25°C, 30°C, and 35°C and observed for up to 100 days. Germinating spores were counted when they were visible to the naked eye. Spore germination at 20 and 25°C in both strains could be observed within three days. Better and more consistent germination was observed in strain MBFBL 400. Germination in 20 spores/100uL dilution was only observed at 20 and 25°C, and it happened between 35 and 83 days after plating. The trend in spore germination from highest to lowest in MBFBL400 was 30>20>15>25>35°C with percentage germination rates of 7.03, 4.06, 2.76, 2.52 and 0.22%, respectively. In MBFBL 67B, the germination percentage ranged from 0 to 1%. We do not understand the relatively low germination in the commercial strain MBFBL67. Further repeats of germination experiments will confirm the observations. However, the trend aligns with results from other strains where the commercial strain of mushrooms exhibits depressed spore germination rates compared to wild strains.
- Abigail Leavitt LaBella, Dana A. Opulente, Marie-Claire Harrison, John F. Wolters, Chao Liu, Yonglin Li, Jacek Kominek, Jacob L. Steenwyk, Hayley R. Stoneman, Jenna VanDenAvond Caroline R. Miller Quinn K. Langdon Margarida Silva,Carla Gonçalves,Emily J. Ubbelohde Yuanning Li, Kelly V. Buh Martin Jarzyna, Max A. B. Haase, Carlos A. Rosa, Neža Čadež ,Diego Libkind, Jeremy H. DeVirgilio, Amanda Beth Hulfachor Cletus P. Kurtzman, José Paulo Sampaio, Paula Gonçalves, Xiaofan Zhou Xing-Xing Shen Marizeth Groenewald, Antonis Rokas, Chris Todd HittingerGenomic factors shape carbon and nitrogen metabolic niche breadth across Saccharomycotina yeasts
The yeasts of the subphylum Saccharomycotina exhibit a wide range of metabolic capabilities. Some yeasts can metabolize a wide range of carbon substrates and are known as generalists. In stark contrast, yeasts that are limited to a small set of carbon substrates are known as specialists. Two general paradigms have been proposed to explain this variation: trade-offs between performance efficiency and breadth and the joint influence of environmental and genomic factors. We leveraged a genomic and phenotypic dataset of 1,154 yeast strains from 1,051 species to identify factors contributing to metabolic niche breadth. We found limited evidence for trade-offs between growth rate and metabolic niche breadth. However, there were differences in gene content associated with the carbon generalists.
- Kathryn N. Maley, M. Catherine Aime
Department of Botany and Plant Pathology, Purdue University, West Lafayette, IndianaThe relationship between local tree diversity and mycorrhizal type is temporally dynamic over 7 decades of Midwestern forest succession
Trees that form arbuscular mycorrhizas (AM trees) are fundamentally different from trees that form ectomycorrhizas (ECM trees) in terms of their resource requirements, chemical outputs, and interactions with neighboring trees. At the community level, the dominant type of mycorrhizal association in a forest is linked to tree diversity, with the lowest diversity occurring in forests dominated by ECM trees. However, there is debate over whether the highest diversity occurs in forests dominated by AM trees (ECM dominance hypothesis) or in forests with approximately even mixtures of AM and ECM trees (mycorrhizal mixture hypothesis). It is also unclear if this relationship changes over time, which could explain discrepancies among studies comparing different forest systems. In this study, we tested the ECM dominance hypothesis and the mycorrhizal mixture hypothesis at a local scale in a temperate forest in Indiana, USA, and we examined how this relationship changed over time. We used historical tree census data spanning 7 decades to determine species richness and proportion of ECM trees in 1,600m2 quadrats (N=33) of forest. Because the ECM dominance hypothesis predicts an inverse proportional relationship between species richness and ECM proportion, we tested this hypothesis by fitting a linear model to each decade’s dataset. Because the mycorrhizal mixture hypothesis predicts a hump-shaped relationship between species richness and ECM proportion, we tested this hypothesis by fitting a quadratic model to each decade’s dataset. We selected the best fit model for each decade and used analysis of variance to determine if the relationship was significant. Results show a significant hump-shaped relationship in mid-to-late successional stages of forest development (1970-1990), but this trend becomes more linear and less defined with time (2009-2019). Our results suggest that the mycorrhizal mixture hypothesis is more accurate than the ECM dominance hypothesis at a local scale, but this relationship is temporally dynamic and only evident at certain stages of forest succession.
- Alison Munaylla-Bohorquez and Megan Romberg
Department of Biology, Marymount University and United States Department of Agriculture, Animal and Plant Health Inspection Service (APHIS), National Identification Services (NIS).Flight of fancy? Uredo calotropidis on the butterfly host Calotropis may be the common Uromyces asclepiadis after all.
In July 2023, a rust on Calotropis gigantea was found in a residential garden in Hawaii and sent to USDA APHIS for a confirmatory identification. Calotropis is a genus of flowering plants, native to South Asia and North Africa, in the Apocynaceae family. Calotropis gigantea in particular played a key role in the arrival of monarch butterflies to Hawaii in 1850 after the host plant was introduced. The Apocynaceae family, comprising approximately 400 genera and 4,555 species, is predominantly distributed across tropical and subtropical regions. Characterized by the presence of milky and toxic latex, along with diverse medicinal properties attributed to cardiac glycosides and alkaloids, this family exhibits a wide array of fruit types, typically dry pods releasing winged or tufted seeds. Taxonomic evaluation of Apocynaceae has been complicated, with the Asclepiadaceae placed in a separate family until the year 2000. The number of rusts reported on tribe Asclepiadeae in the Apocynaceae is a relatively small number, with Puccinia chloridis, P. obliqua and Uromyces asclepiadis commonly reported. This study investigates two rusts in particular that have been reported in literature from Calotropis. In 1952, Cummins described Uredo calotropidis on Calotropis procera in Columbia based on a specimen he had initially identified as Uromyces asclepiadis. U. asclepiadias, described by Cooke in 1877 on Asclepias syriaca in Maine, is a widely reported rust on Asclepias hosts. Cummins stated that, “No rust has been reported on Calotropis and no aselepiadaceous rust has such uredia and urediospores.” At the time the sample was received from Hawaii, no sequences of U. calotropidis or Uromyces asclepiadis were present in GenBank. We present characterization of the sample from Hawaii based on comparison of morphological characters and two gene regions (ITS and LSU) to the type specimen of U. calotropidis (BPI 154479), other BPI specimens of U. calotropidis and Uromyces asclepiadis, and sequences available in RustHubb.
- Thien Nguyen, Min Li, Tao Wu, John P. Munafo Jr.
Department of Food Science, University of Tennessee, KnoxvilleCharacterization of Aroma Molecules in Dried, Rehydrated, and Cooked Lobster Mushrooms
Lobster mushrooms are a type of wild edible mushroom that grow in the temperate forests of North America. They are well-known for their unique seafood-like flavor, which make them a highly sought-after ingredient in fine dining establishments and among food enthusiasts. Interestingly, the lobster mushroom is not a single species but a result of the colonization of certain Russula and Lactarius species by the ascomycetes fungus Hypomyces lactifluorum. As lobster mushrooms are usually only available briefly during the warmer months, they are sold year round as a dried product that needs to be rehydrated before cooking. The seafood aroma of lobster mushrooms intensifies during the cooking process, suggesting the influence of thermal treatment on their aroma. Herein, the important aroma molecules in lobster mushrooms were identified, including a series of alcohols, aldehydes, lactones, and organic acids. Additionally, the differences between dried, rehydrated, and cooked lobster mushrooms were characterized, revealing the influence of the rehydration and cooking processes on their aroma. These findings provide insights into the formation of the unique seafood aroma of lobster mushrooms and can serve as a foundation for future studies on other wild mushrooms with similar aromas.
- Chance Noffsinger1, Slavomír Adamčík2, and Brandon Matheny1
1University of Tennessee, Knoxville, TN, U.S.A. 2Slovak Academy of Sciences, Bratislava, Slovakia.Atmospheric deposition threatens Russula diversity in an endangered spruce-fir ecosystem
Abstract: The spruce-fir ecosystem of the southern Appalachian Mountains is endangered and receives the highest amounts of nitrogen deposition in this region, which negatively impacts the growth, composition, and function of soil organisms. Russula is an important genus of ectomycorrhizal fungi that associates with red spruce (Picea rubens) and Fraser Fir (Abies fraseri); however, no systematic analysis of the genus has been completed in the region. We compared Russula collected from spruce-fir habitats of the southern Appalachian Mountains with collections in the TENN herbarium and reference material from North America and Europe, using an in-depth morphological study and multilocus phylogenetic analysis. Additionally, we sampled 71 soil cores to understand the molecular diversity of Russula belowground as well as species’ ecological preferences. Preliminary analysis of the ITS gene region has tentatively identified 36 species-level clades from basidiomata in the spruce-fir ecosystem. Eight of these species are distributed across eastern North America, including R. peckii, R. paludosa, R. rugulosa, R. fragilis, R. betularum, R. dissimulans, R. granulata, and R. puellaris. Four species appear to have intercontinental distributions that extend into spruce-fir habitats of Europe, including R. claroflava, R. montana, R. aquosa, and R. vesca. The remaining species require further investigation. Additionally, 27 Russula OTUs were identified using ITS2 sequences from soil samples. Preliminary results indicate that some of the Russula species studied may be undescribed based on unique morphological characters and distinct molecular composition. We also determined that pH and nitrogen deposition are negatively influencing the community structure and diversity of Russula within this system, potentially leading to the local extirpation of species. This work has provided valuable information regarding the Russula species present in the spruce-fir ecosystem and how aboveground and belowground diversity differ for large ectomycorrhizal genera.
- Peintner, Ursula1, Bianka Siewert2, Lesley Huymann1, Josefine Lange3, Sophie Schwarzkopf2, Götz Palfner4, Maria Eugenia Salgado Salomon5 and Norbert Arnold3
1Department of Microbiology, University Innsbruck, Austria
2Institute of Pharmacy/Pharmacognosy, University of Innsbruck, Innsbruck, Austria
3Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Germany
4Departamento de Botanica, Universidad de Concepción, Chile
5Centro Forestal CIEFAP, Esquel, ArgentinaShed light on it: taxonomic and chemical diversity of Cortinarius species with photobiologically active pigments from South America
The South American forests contain distinctive tree species that are endemic and represent the oldest lineages of Nothofagus evolution. The associated ectomycorrhizal fungi such as dermocyboid Cortinarius species, are not well explored in these areas. Mutualistic fungi often co-evolve with their associated plant partner. Thus, we hypothesize that these Patagonian Nothofagus forests contain a high diversity of endemic ectomycorrhizal fungi. Taxonomic diversity is usually reflected in metabolic and functional diversity. The pigments of dermocyboid Cortinarii are mainly (pre)Anthraquinones, which are one of the most promising classes of natural photosensitizers. The project aims to sample and describe South American dermocyboid Cortinarii, identify their pigments, and test them for photo-activity. The taxonomy of endemic dermocyboid Cortinarii is addressed based on extensive fieldwork, careful documentation and morphological character evaluation, and multi-gene phylogeny. Thin layer chromatography and mass spectrometry is used to create pigment profiles via desorption electrospray ionization. New species were discovered, and new photoactive pigments were isolated and their chemical structure elucidated. Tests for biological activity with a focus on targeted light activation are ongoing. The results confirm our hypothesis of a high, up to now unhidden diversity of endemic dermocyboid Cortinarius species in these habitats. They contain new anthraquinone compounds, e.g. mapucybin and teresaecolorin. Their potential as new photosynthetisers is described. A systematic study of photobiologically active pigments is promising for medical or biotechnological applications. However, potential in-situ functions of pigments from these fungi are also highlighted.
- Benjamin D. Rose, Marissa A. Dellinger, Clancy P. Larmour, Mira I. Polishook, Maria I. Higuita-Aguirre, Summi Dutta, Rachel L. Cook, Sabine D. Zimmermann, and Kevin Garcia, Dept. of Crop and Soil Sciences and Dept. of Forestry and Environmental Resources, NC State University, and IPSiM, University of Montpellier, CNRS, INRAE, Institut Agro, Montpellier, FranceThe ectomycorrhizal fungus Paxillus ammoniavirescens influences the effects of salinity on loblolly pine in response to potassium availability
Salinity is an increasing problem in coastal areas affected by saltwater intrusion, with deleterious effects on tree health and forest growth. Ectomycorrhizal (ECM) fungi may improve salinity tolerance of host trees, but the impact of external potassium (K+) availability on these effects is still unclear. Here, we performed several experiments with the ECM fungus Paxillus ammoniavirescens and loblolly pine (Pinus taeda L.) in axenic and symbiotic conditions at limited or sufficient K+ and increasing sodium (Na+) concentrations. Growth rate, biomass, and nutrient contents were recorded for the fungus, and the colonization rate, root development parameters, and shoot nutrient accumulation were determined for mycorrhizal and non-mycorrhizal plants. P. ammoniavirescens was tolerant to high salinity, although growth and nutrient concentrations varied with K+ availability and increasing Na+ exposure. While loblolly pine root growth and development decreased with increasing salinity, ECM colonization was unaffected by pine response to salinity. The mycorrhizal influence on loblolly pine salinity response was strongly dependent on external K+ availability. This study reveals that P. ammoniavirescens can reduce Na+ accumulation of salt-exposed loblolly pine, but this effect depends on external K+ availability.
- Daniel J. Taratut1, Joseph P. Calabrese1, Amy L. Kutay1, Brent J. Sewall2, Barrie E. Overton1
1 Department of Biology, Commonwealth University of Pennsylvania, Lock Haven, PA, USA
2 Department of Biology, Temple University, Philadelphia, PA, USACalcofluor White Staining Showed Natural Fungal Colonization of Lycorma delicatula Egg Masses and is a Novel Method to Study In Vitro Entomopathogen Treatment Efficacy
The spotted lanternfly (SLF), Lycorma delicatula, is an invasive leafhopper that causes harm to a variety of plant species. After wild collections of SLF egg masses in 2022, it was observed that contamination by Cladosporium and Fusarium spp. significantly reduced hatch efficacy in storage. Wild SLF egg masses were aseptically collected in Bloomsburg, PA on April 2023; Initial observations revealed extensive mycelial colonization of eggs using Calcofluor white stain. These egg masses were stored at 9°C and 30-35% relative humidity, in complete darkness. Monthly incubations between April and September at 22°C and 65-70% humidity showed increased mycelial colonization over time (R2=0.66). Concomitantly, there was a reduction in hatch success correlated with increased mycelial colonization after 60 days in storage (R2=0.58). The loss in hatch success was correlated with an increase in mycelial colonization (R2=0.74). Dilution plating of untreated 150-day old eggs yielded 10^6 CFU, indicating bio amplification of entomopathogenic fungi (EPF) like Cladosporium spp. and Fusarium spp. Lycorma delicatula and associated EPF were baited on different soils and isolated from multiple SLF life stages. Molecular identification using ITS rDNA and 16S rDNA barcode regions for fungi and bacterial, respectively, were used to ID isolates to species. Pseudomonas fluorescens, a known antifungal bacterium, significantly inhibited Cladosporium spp. growth and germination (p < 0.05), serving as a negative control for treatment experiments. Six known EPF isolates were identified and tested against SLF egg masses in vitro prior to 60 days in 9°C storage. Samsoniella sp. demonstrated increased mycelial colonization on treated egg masses (p < 0.001) despite Cladosporium spp. co-occurrence from natural colonization. Pseudomonas fluorescens exhibited the least fungal colonization (p = 0.008). These findings reveal natural colonization of SLF egg masses by EPF such as Cladosporium spp. and increased mycelial colonization potential when treated with Samsoniella sp. Despite this, no significant reduction in egg hatch success was observed in eggs treated within the 60-day window following aseptic wild collections. These results represent the first documentation of natural colonization of SLF egg masses by known entomopathogens, elucidating several forgotten EPF that can be used to treat egg masses and oviposition sites in nature. Given these findings: i) There is a significant correlation between natural fungal colonization of SLF egg masses over time in storage, and ii) the failure to demonstrate a lowering of hatch success in the 60-day study window suggests that this work should be conducted in the field directly following SLF oviposition to provide EPF treatments a longer window for bio amplification on egg masses to ascertain treatment effects.
- Nkese S. Udombang*, Brandon G. Essick, Nathan Holt, Melvin Mensah-Bonsu, Felicia N. Anike, Omon S. Isikhuemhen.
Mushroom Biology and Fungal Biotechnology Laboratory, Department of Natural Resources & Environmental Design, CAES, North Carolina A&T State University.
Real-Time PCR Analysis of Tuber lyonii Abundance in Truffle Soils Orchard
Truffles, the subterranean fungi highly prized for both their culinary and economic worth, rely heavily on specific soil conditions and microbial interactions to facilitate their growth and subsequent production. Tuber lyonia which is native to the southeastern United States commonly associated with pecan trees is of commercial interest. The presence and abundance of Tuber lyonii DNA within a truffle orchard soils were studied using Real-Time PCR technology. Soil samples were collected from a pecan orchard planted with truffles inoculated trees, which are in production, located at the North Carolina A&T State University School Farm. The orchard was subdivided into five equal sections, and ten samples each were collected from each section. Genomic DNA extracted from the samples were applied in RT-PCR studies of T. lyonii DNA in the orchard soils. T. lyonii DNA was detected in four of the five sections. Section 5 had the highest abundance of T. lyonii DNA with a mean value of 487.11, followed by 283.89, 261.70, and 132.38 µg g-1 in sections 3, 4, and 1, respectively. The truffle yields in the different sections tends to follow the trend of T. lyonii DNA abundance indicated in the RT-PCR analyses. No significant amount of T. lyonii DNA was detected in section 2 of the orchard and no fruiting bodies were collected from this section too. This study suggests that real-time PCR could be a useful tool to evaluate truffle presence and growth dynamics in natural and cultivated fields.
- Roman Whitaker, Nathan Holt, Felicia N. Anike, Omon S. Isikhuemhen.
Mushroom Biology and Fungal Biotechnology Laboratory, Department of Natural Resources & Environmental Design, CAES, North Carolina A&T State University.Effect of Temperature on mycelia growth in a tropical isolate of Pleurotus djamor.
Pleurotus djamor, an edible mushroom, produces clusters of pink fruit bodies in cultivation. With the increasing relevance of high-temperature-tolerant mushrooms due to global warming, we are currently engaged in the collection and identification of Pleurotus species with high-temperature tolerance. This is part of a broader effort aimed at characterizing, breeding, and eventually commercializing high temperature tolerant strains. The fruit body of a Pleurotus sp. was discovered in the wild in Jamaica, and its ITS DNA sequence analysis confirmed it as Pleurotus djamor, designated as Pj795. Our present study focuses on characterizing this isolate based on its mycelial growth on Potato Dextrose Agar (PDA) at different temperatures. A seven-day-old culture of Pj795 was used to inoculate PDA plates and incubated at temperatures of 15°C, 20°C, 25°C, and 30°C for 13 days. Rapid mycelial growth was observed from day 5 at 20°C, 25°C, and 30°C. Throughout the study, the highest mycelial growth was consistently observed at 30°C, measuring 5.38 cm, followed by 225°C with 4.38 cm, 20°C with 2.71 cm, and 15°C with 2.41cm. It was expected that the observed growth behavior of Pj795 is highest at 30°C, given that it was collected in Jamaica, a tropical environment. Ongoing research is focused on breeding and domestication for its potential use in commercial cultivation.
POSTER ABSTRACTS 21-50
- Brooke Allen and Jason Hoeksema. Department of Biology, University of Mississippi.Exploring Biosynthetic Gene Cluster Diversity Across Native and Introduced Populations of Suillus luteus
Non-pathogenic fungi are being increasingly recognized for their involvement in biological invasions, where they have the potential to cause ecological and economical harm due to their tendency to co-invade with invasive plant species. One notable example is the ectomycorrhizal fungus (EMF), Suillus luteus, which is commonly found co-invading with non-native pines that have escaped from commercial pine plantations across the Southern Hemisphere. In these typically non-forested invasion fronts, selection pressures imposed by novel plants, soil microbes, and environmental conditions, as well as greatly impoverished assemblages of other EMF, may exert particularly strong effects and contribute to driving evolutionary divergence in species interactions. We investigated the impact of this global co-introduction on biosynthetic gene cluster (BGC) diversity in native and introduced populations of Suillus luteus.
Terpenes were the most prevalent category of BGCs predicted across all populations. There was no difference in the proportion of BGCs produced between native and introduced populations, which suggests that they possess comparable biosynthetic capacity. Clustering analysis generated 437 distinct gene cluster families (GCFs), with no GCFs conserved across all 258 genomes. The most frequently occurring GCF was associated with terpenes, and was represented in 87.7% of all genomes. There was no clustering pattern observed for native or exotic populations, suggesting no clear divergence in BGC diversity. However, we found that singletons—potentially unique, unclustered BGCs —accounted for 2.85% of introduced population BGCs and 1.34% of native population BGCs. These findings underscore the dynamic nature of BGC diversity in response to invasion, highlighting the importance of considering fungal genomic evolution in ecological contexts.
- Mark Anderson, M. Catherine Aime. Purdue University-Department of Botany and Plant PathologyIn-depth analysis of DNA barcodes for the purpose of elucidating species limit
DNA barcoding attempts to identify a sample to the species level, generally only using a short DNA sequence from the sample. DNA barcoding is especially helpful when morphological traits cannot reliably distinguish species, as is the case with many fungi, including rusts (Basidiomycetes, Pucciniales), the subject of this research. One way DNA barcodes can be used to distinguish species is via sequence similarity: the same species should have higher sequence similarity with conspecific taxa than with other species.Therefore, in order to define species limits in DNA barcodes, the likelihood that a polymorphism among samples of the same species would be present needs to be determined and compared to polymorphism rates of closely related taxa. This study takes the first step in that by analyzing the frequency of polymorphisms present within samples of the same species. Using over 3,000 LSU barcodes of previously-identified samples, sequences of the same species were aligned, and all polymorphisms were counted. Results show that polymorphisms within the same species vary widely by type. Polymorphisms between two pyrimidines and two purines are more likely than any polymorphism between a pyrimidine and a purine, and the amount of polymorphisms observed within species varies among different genera. These results are supported by our current understanding of biochemistry and the phylogeny of rust fungi. Future work will determine differing rates of polymorphism between different species and genera, therefore allowing species limits to be determined based on variation in both the number and type of polymorphisms.. How this improved DNA barcoding methodology can be implemented and its implications for the molecular identification of fungi will be discussed further in this poster.
- Erica Babusci, Amelia Foley and Claudia K. Gunsch
Department of Civil and Environmental Engineering, Duke UniversityThe Development of Microencapsulation Protocols for Improved Fungal Viability
EPA Superfund sites are characterized as locations with hazardous levels of contaminants that require engineered solutions to protect environmental and human health. Polyaromatic hydrocarbons (PAHs) are a group of chemicals that have mutagenic and carcinogenic properties, often prevalent in these Superfund sites. Due to their accumulative and persistent nature in the environment, it is often difficult to remediate PAHs. Mycoremediation is a strategy that utilizes fungi to remove PAHs in a minimally invasive and cost-effective manner. The use of fungi is advantageous because they are resilient in low-nutrient conditions, produce large quantities of reductive enzymes, and can easily compete with other microbes. However, in-situ mycoremediation applications have shown minimal success due to the planktonic cultures’ inability to properly establish within the novel environment. In this project, we aim to develop an encapsulation protocol that better protects the fungi from harsh environmental conditions to improve establishment success, viability, and fitness over longer periods of time. Previously, a library of PAH degrading bacteria and fungi strains have been identified from a PAH contaminated Superfund site. Current methods have been developed to encapsulate the bacteria in the biodegradable polymer sodium alginate, via extrusion. We aim to adapt this protocol to encapsulate fungi, currently focusing on species from the genus Trichoderma, by comparing the growth and viability of planktonic and encapsulated fungal cultures. Methods for quantifying the growth and release of fungi from the microcapsules are under development. These data are essential for determining if current bacterial encapsulation methods are translatable to fungi.
- Spencer Baldwin, Barbara Shock, Whitney Kistler. Lincoln Memorial UniversityUtilizing presence only prediction to model Morchella diminutiva distribution
Morels (Morchella spp.) are recognized for their cultural importance and culinary use; however, some species remain understudied. Morchella diminutiva was formally described in 2012, but little follow up research has occurred. To determine the ecology of M. diminutiva, in situ experiments should be conducted. Utilizing GIS analyses we can create predictive species distribution models to guide future environmental collections and research. The purpose of this study is to develop a predictive model and test the model with mycelia eDNA collections at predicted locations. Using Maxent, we can identify which environmental factor(s) best predicts M. diminutiva growth. After implementing the worldclim bioclimatic data set, we found that coldest quarter mean temperature was the strongest predictive variable with a model AUC of .899. A hotspot map of M. diminutiva predicted distribution was also generated. In summer 2024, we will test the efficacy of the model by collecting soil samples from areas with high, medium, and low presence predictions and screening these samples with molecular techniques. Following field sampling we plan to develop a linear regression model as well as identify the correlation coefficient of prediction to observed presence. These data will assist in understanding the ecology of M. diminutiva as well as provide a workflow for the study of other cryptic species, including plants or wildlife.
- Michal Belle 1 , Abolfazl Dadkhahtehrani 1 , James N. Culver 2 , Priscila Chaverri 1
1 Department of Natural Sciences, Bowie State University, 14000 Jericho Park Road, Bowie, MD 20715, USA; 2 Department of Plant Sciences and Landscape Architecture, University of Maryland,
2102 Plant Sciences Building, 4291 Fieldhouse Drive, College Park, MD 20742, USAMetagenomics and metatranscriptomics unveil a mycovirus diversity
Recent studies have shed light on the presence of endohyphal viruses (mycoviruses),
yet the true extent of the diversity within fungal cells remains largely unexplored.
Understanding the intricate interactions between endohyphal microorganisms and their
fungal hosts and, consequently, their impact on the wider ecological network (e.g.,
multipartite symbiosis: plants-endophytic fungi-mycoviruses), requires more
comprehensive methodologies for their characterization. The objective of this study was
to characterize the DNA and RNA mycovirus diversity from endophytes using
metagenomics and metatranscriptomics. Leaves of Fagus americana trees yielded 120
endophyte isolates, initially identified using ITS nrDNA and further validated using other
From this pool, a subset of 10 isolates representing three Ascomycota orders
(Diaporthales, Glomerellales, and Xylariales) was selected for in-depth analysis. DNA
and RNA extraction from these isolates was followed by shotgun metagenomic and
metatranscriptomic sequencing, and bioinformatic analyses. Preliminary findings reveal
many viral sequences were observed with RNA viruses being more frequent than DNA
viruses. Interestingly, many giant viruses (e.g., Nucleocytoviricota and Pandoravirus)
that are known to replicate in both the host’s cell nucleus and cytoplasm, dominate the
diversity of DNA and RNA viruses. Bacteriophages were also found. In addition, beta-
diversity analyses reveal that mycoviral communities are different between the three
fungal orders. This study further enriches and expands understanding of these complex
and cryptic symbiotic relationships.
- Meredith Blackwell. Department of Biological Sciences, Louisiana State University, Baton Rouge.Wanted Alive: Lobosporangium transversale.
Lobosporangium transversale (Malloch) Benny & Blackwell (Mortierellaceae) was originally described by Malloch (1967) as Echinosporangium transversale. The name change was required because Echinosporangium Malloch is a later homonym of a red algal genus, Echinosporangium Kylin. The distinctive fungus was isolated into culture three times in a two year period from arid soils (Jefferson City, Nevada, Sep 1964, Hermosillo, Sonora, 23 Mar 1965, and Austin, Texas, Feb 1966). Cultures of the Austin and Jefferson City strains were deposited in ATCC, and after methods were developed the DNA sequences of the Jefferson City strain were sequenced and accessioned in GenBank. Multiple immediate attempts to reisolate the fungus from the exact site in Austin were unsuccessful. A large NSF-supported project (ZyGoLife) involved multiple mycologists and their students to develop a phylogeny to study the fungal traits, and in addition “refine molecular environmental sampling techniques, resulting in a more accurate census of zygomycete biodiversity, especially in soil ecosystems.” Despite many eDNA surveys of soil, L. transversale has not been isolated again. At the 2022 MASMC meeting in Clemson, SC, a $500 reward was offered for rediscovering the unusual fungus. The reward has not been claimed and remains on offer.
- Baker, Logan, Danett Vargas, Grace Stanton, Caroline Hankins, Garrett Brandt and Julia
Clemson University.Mycofabrication of acoustic panels: Testing fungal species for maximum sound absorption and ideal panel characteristics
Mycofabrication is the process of using fungi and substrate to create biodegradable materials in place of non-biodegradable materials such as plastics, metal, or glass. These composites are made with a complex of mycelium and organic substrates by using mycelium as natural adhesive to bind the organic materials. Previous mycofabrication research has utilized plant-based substrates for use in textiles, packaging, and construction. The goal of our research is to investigate the effectiveness of mycofabricated panels for sound dampening in indoor settings. These panels can potentially replace traditional acoustic panels, which are often made from synthetic, manufactured materials and may off-gas harmful compounds. A focus on sustainability is promoted using agricultural hemp and the carbon sequestering properties of mycelia. For making the panels, a mold was 3D printed at the Clemson Makerspace, and a panel was created using a commercially available kit (Grow.bio by Ecovative). The species Fomes fomentarius, Ganoderma polychromum, and Trametes versicolor were found to be most suitable based on growth trials in culture. These species are being used individually to inoculate mixtures of hemp, water, and flour, which are molded into panels and baked after growth is complete. Once complete, experiments will test the sound-dampening capabilities of these panels in comparison to traditional acoustic panels. Creating panels from fungal-based composites is advantageous, as their production utilizes agricultural wastes and they are compostable, while also being low cost and requiring minimal energy inputs.
- Hankins, Caroline, Garrett Brandt, Grace Stanton, Logan Baker, Danett Vargas and Julia Kerrigan. Clemson University.Fungal endophytes associated with herbivory by leaf cutter bees in redbud trees
Fungal endophytes often provide benefits such as increased resistance to environmental stresses, protection against pathogens, and enhanced growth. Endophytic fungi are found in various plant species across different ecosystems and play essential roles in plant health and ecosystem dynamics. The objectives of this research are to determine if the presence and species composition of fungal endophytes influence herbivory behaviors of leaf cutter bees (Megachile spp.). A previous study found that a species of Aspergillus may have an influence on leaf cutter bee herbivory on roses. This research seeks to build upon this, examining endophytic fungi of redbud, Cercis canadensis (Fabaceae), and leaf cutter bee activity. Leaves with and without damage caused by leaf cutter bees were collected, leaves were surface sterilized, and fungi were allowed to grow on several types of media containing antibiotics. Cultures were maintained, and from each isolate DNA was extracted and quantified, amplification of the ITS region was performed, and DNA sequencing is underway. We expect to present the taxa present in these samples and any conclusions that may be made. Our goal is to provide more information regarding the complex interactions of endophytic fungi, insects, and plants.
- Rebecca Busch1, Carson Doty2, Allie Mills3, Flutur Latifi2, Vjollca Konjufca2, Laura Herring3, and José Vargas-Muñiz1 / 1. Department of Biological Sciences, Virginia Tech, Blacksburg, VA 2. School of Biological Sciences, Southern Illinois University-Carbondale, Carbondale IL 3. Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NCDeletion of core septin genes in Aspergillus fumigatus results in fungicidal activity of caspofungin
Septins are a family of GTP-binding proteins. Although highly conserved throughout many eukaryotes, their functions vary across species. In Aspergillus fumigatus, the etiological agent of invasive aspergillosis, septins participate in a variety of roles such as cell wall organization of conidia, septation, and response to anti-cell wall stress. Previous studies determined that the ∆aspB strain had a greater sensitivity to anti-cell wall drugs, especially the echinocandin caspofungin, yet mechanisms behind this augmented sensitivity are unknown. We performed cell viability staining post-caspofungin exposure and found that the ∆aspA, ∆aspB, and ∆aspC strains showed significant reduction in cell viability. Concomitant with the reduced viability, deletion strains are more susceptible to caspofungin on solid media. These results indicate that the septin cytoskeleton is important for A. fumigatus survival in the presence of caspofungin. Due to the potential of improved therapeutic outcome, we followed up using a neutropenic murine model of invasive aspergillosis. Deletion of the aspB gene resulted in improved survival, reduced pulmonary inflammation, and reduced fungal burden when treated with caspofungin, compared to the akuBKU80 wild-type or untreated ∆aspB strains. Quantitative proteomics analyses were used to find proteins involved in the septin-dependent adaptation to caspofungin. We identified four candidates with roles in cell wall integrity. Deletion of these candidate genes resulted in increase in susceptibility to caspofungin and moderate reduction in viability post-drug exposure. Taken together, these data suggest that septin AspB is essential in mediating the fungistatic response to caspofungin.
- Damion Castellano and Emily Cantonwine*, Department of Biology, Valdosta State University, Valdosta, GA 31698Linking Nothopassalora personata haustoria and hyphae to late leaf spot symptoms in peanut.
Primary symptoms of early and late leaf spot diseases of peanut (Arachis hypogaea), caused by Passalora arachidicola and Nothopassalora personata, respectively, are 1-5 mm wide necrotic lesions, with or without a yellow halo. Unlike most other hemibiotrophic cercosporoids, including P. arachidicola, N. personata uses haustoria, along with intercellular hyphae, to invade host tissues. Although host resistance often differs for these pathogens, little is known about how resistance genes affect pathogen colonization. This study compared the presence of N. personata haustoria and colonizing hyphae with late leaf spot symptoms for a susceptible peanut cultivar and three genotypes with enhanced resistance. Mature lesions, 3 mm wide with a yellow halo, were cleared with visikol and stained with cotton blue for microscopic analysis. The chlorotic ring size and distances of haustoria and mycelium were measured from the necrotic margin. Hyphae extended 30 to 40% farther than haustoria (P<0.01), but no genotype differences in chlorotic ring size or haustoria distances were noted (P>0.05). However, hyphae were longer for the susceptible cultivar than the resistant lines (P<0.01), extending beyond the chlorotic ring for the susceptible cultivar only. These results suggest that the resistance genes of these lines are not targeting haustoria at this disease stage, but that colonizing hyphae are affected. Experiments to differentially characterize the biochemical and cellular responses of these genotypes to N. personata structures are underway.
- Jackson Cooper, Maria Von Cräutlein, Sanna Elina Olsson, Kari Saikkonen, Marjo Helander, Carolyn Young
Department of Entomology and Plant Pathology, North Carolina State University, Raleigh NC; Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland, Finland; Biodiversity Unit, University of Turku, Turku, Finland; Department of Biology, University of Turku, Turku, FinlandEpichloё festucae, a Diverse Bioprotectant Producing Symbiont in the Host, Festuca rubra.
Epichloё festucae is an endophytic fungus that lives in the above ground tissue of Festuca rubra, a cool season grass with wide ecological distribution. Epichloё are known to provide bioprotective traits to their grass hosts through the production of alkaloids, such as ergot alkaloids (EAS), indole-diterpenes (IDT), pyrrolizidines (lolines) and pyrrolopyrazines (e.g. peramine), for which the species E. festucae has been reported to produce all of these compounds. To build a better understanding of the natural diversity in alkaloid biosynthetic genes, nine E. festucae strains isolated from Festuca plants were sequenced from geographically isolated populations covering the distribution range of the species, representing the following locations: Finland, Sweden, Switzerland (2), Spain, the Faroe Islands, Iceland, Alaska, and Canada. Each of these genomes were evaluated for the presence of EAS and IDT genes. Eight out of the nine genomes had the 11 EAS genes required for the production of ergovaline. Although, isolate RBS3-21-1 contained fragmented sequences of easE and lpsA, likely due to poor assembly quality and low coverage. Six of the nine isolates contained IDT biosynthetic genes, but only three isolates, Alv-24-1, CAN-3-37, RBS3-21-1, are predicted to produce IDTs such as terpendoles. These three isolates lack idtE and idtJ so would not be able to produce lolitrem B. The isolates, BIEZ-4-2, Tool-8-21 and SPDG-28, lacked the early pathway genes idtG and idtM (BIEZ-4-2, Tool-8-21) or idtC and idtB (SPDG-28). Three of the isolates (Alv-24-1, BIEZ-4-2 and RBS3-21-1) had a previously reported frameshift mutation in idtF that would render this gene nonfunctional. RBS3-21-1 also appeared to have a nonfunctional idtK gene due to a C to T transition that resulted in a premature stop codon that would prematurely truncate the gene. When evaluating the housekeeping genes, tefA and tubB, these isolates all grouped with E. festucae. The phylogenies of all EAS genes were consistent with the housekeeping gene phylogenies for tefA and tubB. Whereas the phylogenies of the IDT genes did not follow this pattern. Unlike the EAS genes, the phylogenies of the IDT genes showed variation, with idtP and idtQ from Alv-24-1, BIEZ-4-2 and RBS3-21-1 (north central European isolated from Sweden, Switzerland, and Finland) all grouped with E. bromicola. Whereas the other IDT genes grouped with E. festucae as expected. These disparate phylogenies provide evidence of transpecies polymorphism, a phenomenon responsible for variation of the perA gene in Epichloё. Future population and ecological studies will enable us to glean more information on the prevalence of these alkaloid chemotypes and their ecological roles.
- Lauren Dineen, David Wilson, Abigail Leavitt LaBella
Department of Bioinformatics and Genomics, North Carolina Research Campus, University of North Carolina at Charlotte, Kannapolis, NC USA.Computational analysis reveals the diversity of tRNA modifying enzymes across an entire fungal subphylum
An emerging field of tRNA biology has been developing over the past decade. Traditionally tRNA molecules have been placed at the centre of translation machinery however research now pinpoints tRNA as having a major role in mediating stress response in eukaryotes. Despite the major advances in this field, we still know very little about tRNA dynamics and the role of tRNA gene diversity. Furthermore, there is a distinct lack of cross species data, leading to a gap in our fundamental understanding of tRNA in fungi. tRNA undergo extensive pre-possessing and are highly modified by tRNA modification enzymes. tRNA modifications play roles in both maintaining and expanding tRNA decoding capabilities. These enzymes act in site and base specific manners and require multi-enzymatic biosynthesis pathways. Furthermore, tRNA modifying enzymes have been previously shown to have antifungal target potential. Despite their importance, the diversity of modifying enzyme repertoires across several fungal species has not yet been explored. Here we present an investigation into tRNA modification enzyme diversity using a set of over 1000 budding yeast genomes. We employ machine learning techniques to predict tRNA modification enzyme annotations across an entire fungal subphylum, the Saccharomycotina. We find a wealth of variation within the subphylum and draw focus on three distinct tRNA modification pathways acting on the anticodon stem of tRNA molecules. We observe the tRNA modification enzyme diversity on a previously unseen scale, and as a result provide new insights into tRNA biology. We also raise new questions concerning the evolution of tRNA modification enzyme repertoires and tRNA diversity in fungi.
- Megan Dudenhoeffer, Mark T. Banik, Daniel L. Lindner, Michelle A. Jusino
USDA Forest Service, Northern Research Station, Center for Forest Mycology ResearchDeveloping molecular methods to detect and quantify the spread of an invasive wood decay fungus
The ability to colonize novel environments and spread rapidly allows alien species to become successful invaders. In North America, the Golden Oyster Mushroom (Pleurotus citrinopileatus; hereafter GOM) is an invasive wood-decay fungus that has spread rapidly in the Midwestern and Northeastern US since it escaped cultivation. Cultivated GOM has been selected to colonize substrates quickly and fruit prolifically; these traits are evident in invasive GOM which fruits and sporulates abundantly. To be successful, wood decay fungi must be effectively dispersed and be able to colonize suitable substrates; therefore, we are investigating how GOM colonizes wood and disperses to new spatial areas. Quantitative PCR (qPCR) is a fast, sensitive, and relatively cheap molecular method for detecting and quantifying DNA of interest. Our goal is to develop a qPCR assay for GOM, which we will utilize to detect and quantify GOM DNA, both in laboratory and environmental samples. We will develop qPCR probes using GOM isolates and close relatives using Sanger sequencing of commonly used gene regions. Once the qPCR probes have been rigorously tested for specificity using GOM isolates, spore dilutions, closely related species, and native wood decay fungi, we will validate the qPCR assay using different environmental substrates with and without GOM. qPCR probes are useful tools that have a wide range of applications, such as detection of GOM DNA in environmental samples and potential vectors and quantification of colonization and competitive success of GOM. Understanding the mechanisms that assist the establishment and spread of invasive species is essential for predicting future distributions and potential ecological consequences of invasion.
- Rosie George-Ambrocio; William & Mary, Biology Department, Williamsburg, VA
Michelle A. Jusino; USDA Forest Service, Northern Research Station, Center for Forest Mycology Research, Madison, WI
James Skelton; William & Mary, Biology Department, Williamsburg, VAFungus farming ambrosia beetles and their contribution to fungal assemblages and decomposition in wood
The majority of terrestrial biomass is wood, and specialized wood-decaying fungi releases the carbon stored in wood. Due to the vast fluxes of carbon from wood, wood decomposition impacts global carbon cycles and climate. However, fungal succession and competition determines decomposition rates. Fungus farming ambrosia beetles are among the first to colonize dying trees. They bore into wood and inoculate it with diverse lineages of fungal symbionts. Beetle-associated fungi were historically thought to increase wood decay and carbon release, but recent research suggests that in some contexts they may slow decay through competition with wood-decaying fungi. Due to international trade, invasive non-native ambrosia beetles are spreading around the globe. It is unknown if non-native beetles and their fungi change decomposition rates in the invaded regions or if these impacts vary among tree species. Our study utilized surveys of local ambrosia beetle communities, a beetle exclosure experiment, and DNA multi-marker (ITS2 and LSU) metabarcoding to observe the ambrosia symbiosis and measure its impact on fungal community assembly and wood decomposition in logs from four disparately related tree species. We tested the hypothesis that non-native fungi associated with recently introduced and hyperabundant non-native ambrosia beetles suppress wood decay and compete with native fungi. Most observed ambrosia beetles were non-native. Ambrosia beetles readily colonized all 4 hardwood tree species (American Beech, Red Maple, Bitternut Hickory, and Southern Magnolia). Colonization from ambrosia beetles caused a substantial increase in fungal diversity in all tree species. While some of this increased diversity was due to the consistent addition of known fungal symbionts including several species of Ambrosiella, Geosmithia, and Raffaelea, the majority was represented by inconsistent associations with environmental fungi. The two markers highlighted different components of beetle associated fungal communities with ITS2 emphasizing Microascalean symbionts and LSU emphasizing Ophiostomatalean symbionts, demonstrating the necessity of multi-marker approaches to study the complete ambrosia beetle mycobiome. Lastly, fine scale geographic variation in ambrosia beetle assemblages drove corresponding variation in the fungal communities within exposed logs. As non-native symbioses invade, it is imperative that we understand the native ecosystem’s unexplored response.
- Natasha Goldson, Megan K. Romberg, Abolfazl Dadkhahtehrani, Lisa A. Castlebury, Priscila Chaverri
Department of Natural Sciences, Bowie State University, 14000 Jericho Park Road, Bowie, MD 20715, USA; USDA APHIS PPQ NIS, Bldg. 010A, BARC-West, 10300 Baltimore Avenue, Beltsville, MD 20705, USA; USDA ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory, Bldg. 010A, BARC-West, 10300 Baltimore Avenue, Beltsville, MD 20705, USAA new species of Entyloma (Entylomatales, Exobasidiomycetes) on the ornamental plant Eryngium planum expands the E. eryngium species complex
The plant genus Eryngium (Apiaceae) includes various species used as condiments, ornamentals in gardens, or as elements in floral arrangements. In recent years, there has been a surge in interceptions from South America at U.S. ports of entry, leading to the subsequent destruction of these plants due to the presence of an unidentified species of Entyloma (Entylomatales, Exobasidiomycetes). Despite the resemblance of host samples to Er. planum, the limited plant material complicates host identification. Moreover, the morphology of teliospores and the asexual state does not align with any published species on Eryngium. This study aims to identify and characterize this unknown Entyloma sp., ascertain its phylogenetic relationship with other Entyloma species on Eryngium, and verify the identity of the host plant. Morphological and phylogenetic (ITS nrDNA) analyses were performed, in context with known species of Entyloma. ITS nrDNA was also used to attempt the identification of the host. Initial findings reveal that the unidentified Entyloma sp. forms a distinct and well-supported clade separate from other species on Eryngium and Er. aff. planum. Its closest relatives include En. carmeli, En. eryngii, En. eryngii-cretici, En. eryngii-plani, En. lagoeciae, and En. scandicis. Morphologically, it resembles En. argentiniense; however, no molecular data is available for that species and its host is Er. nudicaule. Therefore, a new species of Entyloma is proposed. The host plant was identified as Er. planum. This research increases knowledge of Entyloma diversity and contributes to understanding the dynamics of pathogen movement and potential invasion into new territories.
- Mary Grace Graddy, Dr. P. Brandon Matheny, & Chance NoffsingerMolecular annotation of North American types of Crepidotus reveals a high rate of species synonymy
Estimates of species diversity within the genus Crepidotus (Crepidotaceae, Agaricales) differ by an order of magnitude between North America (ca. 140 taxa) and Europe (ca. 30 taxa). However, it is not known if this difference is due to higher overall diversification of Crepidotus within North America relative to Europe or an artifact of taxonomic over-description by North American taxonomists. To evaluate these perspectives, we produced molecular annotations (at least partial ITS and/or partial 28S rDNA) of 38 of 42 collections labeled as Crepidotus and “type” at the University of Tennessee Herbarium (TENN). Using a combination of operational and phylogenetic approaches, we demonstrate that 16 of the 38 type collections represent autonomous taxa and 22 are contaxic with other accepted names and should be accepted as later synonyms. Several species were described more than once over the years by L.R. Hesler and A.H. Smith, viz, C. applanatus, C. brunnescens, C. crocophyllus, C. eburneus, C. fimbriatus, C. malachius, C. viscidipyllus. This amounts to a synonymization rate of 58%. Extrapolating from this figure, we estimate North America may feature only ca. 80 taxa of Crepidotus without taking into account projections for any truly undescribed diversity. This study is significant because it suggests that the taxonomic practices of L.R. Hesler and A.H. Smith may have resulted in taxonomic over-description in other saprotrophic genera subject to similar monographic treatments and methods, which often included recognition of species based on morphology only, study of single or few collections, and emphasis on overly plastic morphological traits.
- Malik Henry*, Brandon G. Essick, Nathan Holt, Felicia N. Anike, Omon S. Isikhuemhen.
Mushroom Biology and Fungal Biotechnology Laboratory, Department of Natural Resources & Environmental Design, CAES, North Carolina A&T State University.Low-cost Pasteurization system for on-farm small scale mushroom production
Pleurotus species (Oyster mushrooms) are the second most cultivated edible mushrooms in the world. The local ecological niche, ease of growth, and high Biological Efficiency make them suitable for local production and farm profitability. However, production is hindered by the high cost of autoclaves for substrate sterilization. The project seeks to design, develop, and test a modular low-cost pasteurization system that could be adopted onsite by small-scale farmers. The efficacy of the pasteurization system is determined as follows: Corn Stover substrate is soaked in water at room temperature for 12 hours and drained. Substrate with wheat bran (10%) are loaded into bags and pasteurized at five different time points T1-T6 (T1: 4hrs; T2: 6hrs; T3: 8hrs; T4: 10hrs; T5: 12hrs, T6: Control). Substrate bags are inoculated with 5% spawn, incubated at 25°C for 4 weeks, and fruited. The bacterial and fungal load of each treatment are determined. We hypothesize that pasteurization between 10-12 hours will compare favorably with autoclaving.
- Aishwarya Veerabahu (1,2), Mark T. Banik (1), Daniel L. Lindner (1), Anne Pringle (2), Michelle A. Jusino (1)
(1) USDA Forest Service, Northern Research Station, Center for Forest Mycology Research, Madison, WI
(2) University of Wisconsin-Madison, Department of Botany, Madison, WIA golden opportunity to study the impacts of an invasive wood decay fungus
The Golden Oyster Mushroom (GOM; Pleurotus citrinopileatus) is an invasive, edible wood decay fungus found throughout the Midwestern and Northeastern United States. This fungus is native to northeastern Asia and was introduced near southern Wisconsin via commercial strains sold for home cultivation. GOM continues to rapidly spread, with sightings growing exponentially. GOM fruits prolifically from April to November and is highly concentrated in forested areas between the 40 – 45th parallels, from the East Coast to just past the Mississippi River. Though there are few documented examples of invasive decay fungi, there are likely many undocumented invasions. Invasive wood decay fungi spreading in a new habitat may become competitively dominant, displacing native fungi. Our broad objective is to document how GOM affects the ecology in its invaded range, and use this information to inform the management of GOM and model the risks of invasive wood decay fungi. We predict that the presence of GOM is associated with a drastic shift in fungal community composition and function. To test this, drilled wood samples from pairs of GOM and non-GOM trees from Dane County, Wisconsin were collected and their ITS regions were sequenced using high-throughput amplicon sequencing. Samples taken from different heights within each tree were also compared to examine differences in colonization and communities throughout trees. Because wood decomposition is driven by the community of wood-decaying organisms in the wood, disruption or displacement of the community by an invasive will impact the original carbon cycling regime, with significant implications for climate change.
- Chinyere Knight, PhD and Rania Mohamedelhassan
Tuskegee University, Department of BiologyFungi Detectives: The biodiversity, ecology and evolution of fungi from a student antibiotic investigators perspective
To boost systemic change in STEM, the integration of research courses into the biology curriculum is highly recommended. The work described herein reflects this focus. Antibiotic resistance is a threat to animal, human and environmental health. Investigating the understudied fungi are certain to elucidate novel secondary metabolites including antibiotics. The purpose of this project was to co-develop and implement the Mycological Curriculum for Education and Discovery (Myco-Ed), a Course-based Undergraduate Research Experience (CURE) at Tuskegee University (TU). Specific aims of Myco-Ed were to enable students to: 1. Culture fungi from the Dr. Lafayette Frederick Collection 2. Confirm the identity of specimens using ITS1/ITS4 molecular markers 3. Submit novel strains for genome sequencing and analysis to Joint Genome Institute (JGI) MycoCosm and 4. Practice comparative genomics using R studio and the MycoCosm platform to investigate secondary metabolites for antibiotic use. Six unique fungal strains Aleurodiscus thailandicus, Heterobasidion araucariae, Hydnoporia laricicola, Diatrype lijiangensis, Peniophora crassitunicata and Efibula americana were identified and will be metabarcoded by Joint Genome Institute (JGI) and deposited in MycoCosm. Bioinformatics protocols were developed and students were trained to retrieve antibiotic sequences from MycoCosm, NCBI Blast and analyze using R studio. Protocols have been archived in Protocol.io to share with the community. The preservation and characterization of specimens from a historical collection has transitioned a traditional undergraduate biology course into Myco-Ed. Myco-Ed will provide field, laboratory and bioinformatics training empowering TU students. Future studies will assess teaching and learning gains.
- Clancy P. Larmour (1), Maria I. Higuita-Aguirre (1,2), Benjamin D. Rose (1,2), Summi Dutta (1), Kevin Garcia (1)
(1) Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
(2) Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USAOptimizing the culture conditions of the ectomycorrhizal fungus Amanita persicina and confirmation of symbiosis with Quercus falcata and Pinus taeda
Amanita persicina (formerly Amanita muscaria var. persicina) is a native species of the southeastern U.S. reported to be able to associate with trees in Pinaceae and Fagaceae. Amanita is a prominent genus of fungi containing well documented, cosmopolitan ectomycorrhizal species. Despite their prevalence, research into Amanita is challenging mainly due to slow culturing time. Understanding the relatively quick growing A. persicina in controlled environments may give insight into the role of related species in the southeastern U.S. and beyond. Axenic culturing experiments were done using a local A. persicina isolate regarding optimal carbon:nitrogen ratio (2:1, 20:1, and 40:1). Plate and liquid cultures containing Modified Melin-Norkrans (MMN) medium were used at these three carbon:nitrogen ratios in order to gauge the effect on radial growth and biomass response. Simultaneously, co-culture experiments with loblolly pine (Pinus taeda) and southern red oak (Quercus falcata) were done to confirm the ability of A. persicina to associate with local prevalent tree species. Sterile seedlings of both species were inoculated with a liquid fungal slurry and grown for eight weeks after which colonization was determined. Increased carbon:nitrogen ratio significantly decreased radial growth, however, the same increase had no impact on fungal biomass, suggesting an influence on mycelial density. Successful colonization was observed on both P. taeda and Q. falcata seedlings. A. persicina appears to be a versatile species able to associate with common species from the southeast. Further co-culture research is being conducted on the role of A. persicina in nutrient uptake.
- Julian Liber(a), Audrey Williams(b), Claudia Petrucco(c), Alex Crocker(d), Amy Gladfelter(b), Sheng Yang He(a,e)
(a)Department of Biology, Duke University, (b)Department of Cell Biology, Duke University, (c)Department of Pharmacology and Cancer Biology, Duke University, (d)Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, (e)Howard Hughes Medical InstituteUncovering genetic bases of phyllosphere commensalism in the biocontrol yeast Aureobasidium pullulans
Aureobasidium pullulans is a dimorphic, melanized yeast which thrives in habitats from the leaves, flowers, and fruits of crop plants to indoor environments and poly-extremes of salinity, radiation, and cold. It is used as a biocontrol against fungal pathogens and is a common native commensal of many crops. Its protective qualities suggest the importance of its plant-commensal lifestyle, but the genetic bases of traits required for colonization, persistence, and beneficial functions are not well studied. This yeast has promising characteristics for understanding these traits, including a moderately small, haploid, and frequently recombining genome, high phenotypic and genetic diversity, genetic tools for gene deletion and insertion, and ease of isolation and identification. We aim to identify traits of A. pullulans which are important to plant colonization, identify the genetic variants associated with these traits, and test for their impact on host colonization and biocontrol. This is being accomplished by developing a genome-sequenced panel of 190 A. pullulans genotypes, examining phenotypes relevant to stress tolerance, nutrient acquisition, host immunogenicity, and microbe-microbe interactions, identifying phenotype-variant associations, and conducting gene deletion and complementation experiments in vitro and en planta. Our isolate panel is intended to serve as a community resource for understanding the ecology, physiology, genetics, and cell biology of this important constituent of the plant microbiome.
- Aidan Marshall1, Rebecca Busch1 & José Vargas-Muñiz1,2,3 .
1 Department of Biological Sciences, Virginia Tech, Blacksburg, VA
2 Fralin Life Science Institute, Virginia Tech, Blacksburg, VA
3 Whitman Fellow, Marine Biological Laboratory, Woods Hole, MAInvestigating host invasion strategies of Pseudogymnoascus destructans as potential treatment focuses
Pseudogymnoascus destructans (Pd) is an Ascomycete fungus that started causing disease in North American bats in 2009. Disease pathology is characterized by infiltration of cutaneous tissues, particularly those of the nose and wings. In the nose of bats the infection is characterized by the fuzzy white hyphal growth, leading to the name “White Nose Syndrome.” This infection has a high mortality rate in hibernating bats, with significant variations in mortality across species. A novel hypothesis published in 2022 proposed that Pd stems from plant-associated fungi, and that it may have retained and repurposed molecular tools for plant tissue invasion for tissues in bats. This is evident in the wing lesion, as the bat shows potential biotrophic growth. Many phytopathogenic fungi utilize secondary structures, namely appressoria, to penetrate and invade host cells. Host tissue invasion is a key step for disease establishment and an ideal candidate for preventive approaches. Due to the evolutionary history of Pd, we aim to understand if Pd employ similar strategies as plant pathogens to invade host tissues. First we will assess whether Pd can form appressoria in vitro using hydrophobic surfaces. Preliminary analyses showed that Pd can germinate without a carbon source allowing for growth in nutrient deficient conditions that could trigger appressoria formation. If Pd can form appressoria, we will be testing whether melanin production inhibits the formation of those appressoria. In parallel, we will be determining which genes regulate and facilitate host invasion in Pd using forward and reverse genetic approaches.. We will characterize the role of septins and the HOG signaling pathway in host tissue invasion and pathogenesis using a pig’s ear and the Galleria mellonella larvae model. Lastly, we will generate a library of mutant strains of Pd using agrobacterium-mediated transformation. This library of mutants will be screened for defects in phenotypes related to pathogenicity and increase susceptibility to existing antifungal drugs. These new molecular tools will help with further our understanding of White Nose Syndrome in bats and provide a critical understanding that could lead to a future intervention strategy.
- Polina Mironova 1, Christopher C. Wirth 2, Danny Haelewaters 3, Mary Catherine Aime 1
1Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
2Department of Entomology, Purdue University, West Lafayette, IN, USA
3Research Group Mycology, Department of Biology, Ghent University, Ghent, BelgiumSeeking microfungal ectobionts (Laboulbeniales) on rove beetles in the Purdue Entomological Research Collection
Laboulbeniales is an order of microscopic fungi strictly associated as ectobionts with arthropods. They have a distinct morphology due to their three-dimensional, multicellular thalli which are determinate in growth, contrasting with related fungi that are characterized by indeterminate hyphal growth. The thalli stay preserved on the host body for an indefinite amount of time whether the host is pinned, point-mounted, or stored in ethanol. Their presence can be confirmed by screening the insect under a stereomicroscope or, in some cases, by naked eye observation (e.g., Hesperomyces harmoniae on Harmonia axyridis). Dried pinned or point-mounted specimens from entomological collections form a valuable resource for those studying Laboulbeniales, as entomological collections consolidate many host specimens from diverse taxa and locations in one place. The Purdue Entomological Research Collection (PERC) houses over 1.3 million specimens, representing about 140,000 species including 11,135 rove beetle specimens. Over 1,990 PERC specimens from 5 different subfamilies, 46 genera, and at least 106 species of rove beetles (Staphylinidae) were screened for the presence of Laboulbeniales. Among these, ten infected beetles were found: three specimens of an ant-loving beetle (Arthmius gracilior) infected with Cryptandromyces sp., one specimen of a shining fungus beetle (Scaphidium quadriguttatum) infected with Laboulbenia sp., and multiple specimens of Hesperus apicialis infected with two morphotypes of Peyritschiella vulgata. The low prevalence (0.55%) of the thalli on the hosts aligns with previous studies on Laboulbeniales. Screening natural history collections remains important for discovering new species and host associations, as well as studying their geographical distribution across space and time.
- Mira Polishook and Rytas Vilgalys (Duke University).Fungi of the Duke Forest
“Fungi of the Duke Forest” (1938) by Dr. Frederick A. Wolf is a historical bulletin documenting over 550 species of fungi found in the Duke Forest. In the 86 years since publication, the field of mycology has progressed greatly, rendering this resource valuable but outdated. In this update to FDF, I update and expand upon Wolf’s original work by resolving the nomenclature and taxonomy of his species list, confirming the relevance of this historical record with modern collections. Wolf’s original list included 43 Myxomycetes, 17 Phycomycetes, 146 Ascomycetes, 257 Basidiomycetes, and 105 Fungi Imperfecti, but with current taxonomic knowledge, these species are now sorted into 44 Myxomycota, 13 Oomycota, 1 Mucoromyctoa, 2 Chytridiomycota, 249 Ascomycota, and 258 Basidiomycota. To Wolf’s original list, I also provide an additional checklist of species from more recent herbarium collections, as well as new records from the Duke Forest Mycological Observatory, personal collections, mycology classes, and citizen science. More information is provided for the Agaricomycetes, including many iconic mushroom-forming fungi, providing a more complete picture of fungal diversity in the Duke Forest. The results of this study will include a digital database as well as a physical publication with an accurate checklist, descriptions and photographs of common macrofungi, and an overview of the rich history of mycological research in the Duke Forest. By synthesizing all these aspects, I provide a new resource for researchers, citizens, and Duke Forest management.
- Nicole K. Reynolds1, Kevin Amses2, Jessie Uehling3, Rasheed Adeleke4, Margaret Branine5, Teresa E. Pawlowska1
1Cornell University, School of Integrative Plant Science, Ithaca, NY, USA; 2University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA; 3Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR, USA; 4North-West University, Unit for Environmental Sciences and Management, Potchefstroom, North West Province, SA; 5Cornell University, Graduate Field of Microbiology, Ithaca, NY, USA
Dispersal and biotic filtering structure Mucoromycota fungal communities and their associated bacteria across two different biomesDespite the ecological importance of Mucoromycota fungi as mycorrhizal symbionts, opportunistic human and plant pathogens, and post-harvest spoilage agents, they remain understudied compared to Dikarya. Fundamental aspects such as geographical distribution, dispersal patterns, and community structure remain unclear. Furthermore, recent and ongoing discoveries about the endosymbiotic bacteria (EB) that many Mucoromycota species harbor have generated new questions regarding their effects on fungal host evolution. EB have different effects on the host fungi depending on the species, influencing asexual and sexual reproduction and metabolic functioning. Our investigations of Mucoromycota and their associated bacteria communities are focused on testing three main community filtering hypotheses: dispersal (based on geographic distance), biotic (influenced by plant communities), and environmental (incorporating abiotic variables). We collected rhizosphere soils from four total locations in California representing two biomes (Desert and Mediterranean scrub) with three transects and two different plant species sampled from each site. These samples are being analyzed using both culture dependent and culture independent (metabarcoding) methods. We tested a nested PCR approach to facilitate detection of putative EB from soil samples. Metabarcoding data were generated using bacterial (16S rDNA) and fungal (28S rDNA) primers and show desert communities had higher proportions of Zoopagomycota taxa, whereas the coastal samples had more mycorrhizal taxa (Glomerales and Endogonales), with several OTUs unique to each habitat. The 16S nested PCR successfully enriched amplicons assigned to known EB groups, with community differences which corresponded with fungal community patterns. Both biotic filtering and dispersal filtering significantly affected fungal and bacterial communities; however, dispersal filtering was only significant over larger distances (km rather than m scale). In addition, desert samples had a higher proportion of fungal OTUs assigned to opportunistic human pathogenic species not detected from the coast. These results suggest that desert environments are likely reservoirs for these pathogens.
- *Thomas Hilling, *Kayla Deguzman, +Mark Pokras, *Hannah Reynolds
*Biology Department, Western Connecticut State University and +Cummings School of Veterinary Medicine, Tufts University
Thermotolerant fungi from nests and the respiratory system of the common loon (Gavia immer)
The common loon, Gavia immer, faces multiple natural and manmade threats. Fungal respiratory disease in birds is a major contributor to mortality, with Aspergillus fumigatus the top cause of disease. It is not clear where or how loons become infected with fungal disease, and it is possible that they are exposed to high levels of A. fumigatus in nesting materials. We hypothesized that loon demographics (sex, age) or geography could affect the frequency of fungal respiratory disease and/or A. fumigatus. In a long term study on causes of loon morbidity and mortality, deceased loons are collected throughout the northeast and necropsied. We isolated thermotolerant fungi from necropsied loon respiratory tracts and loon nests to evaluate the possible contributions of geography, sex, age, and nesting ecology to respiratory fungal disease. We tested 86 loons, taking samples from the air sacs, tracheae, and lungs. If present, visible fungal plaques were also removed and used for inoculation. Loons nest near or on freshwater and vacate their nests after their chicks hatch. We visited 104 vacated loon nests in Maine and Vermont and tested them for thermotolerant fungi using a culture-based approach. All fungal isolates were cultured in modified Sabaraud dextrose agar at 37℃. Fungi were identified using ITS sequencing, and A. fumigatus isolates were genotyped using a modified StrAf microsatellite assay. A subset of the veterinary A. fumigatus isolates were tested for resistance to the antifungals Amphotericin B and itraconazole, using an E-strip assay on RPMI agar. Respiratory fungal disease was the third highest cause of death in the 2008-2022 long term study. We found that loon demographics and geography did not significantly correlate with fungal respiratory disease or A. fumigatus presence in carcasses or nests, and that A. fumigatus was found in loons lacking visible signs of respiratory infection. We evaluated several nesting site factors and found that loon hatch success was higher when nests were on artificial nesting platforms rather than on the shore. As predicted, microsatellite analysis indicated high genetic diversity with no apparent geographic structure. A. fumigatus diversity was also high within individuals, with multiple genotypes found in 6 of 27 loons.
- Caiafa, Marcos V., Paulo H. Grazziotti, Elena Karlsen-Ayala, Michelle A. Jusino, Rosanne Healy, Nicole K. Reynolds, Matthew E. Smith
Department of Plant Pathology, University of Florida, USA and Universidade Federal dos Vales do Jequitinhonha e Mucuri, Brazil
Ectomycorrhizal fungal communities associated with Crocanthemum and Lechea (Cistaceae) in subtropical Florida sandhill habitats
Cistaceae are shrubs, subshrubs and herbs that often occur in stressful, fire-prone or disturbed environments and form ectomycorrhizal (ECM) associations with symbiotic fungi. Although some Cistaceae are long-lived shrubs that grow to significant size, others are herbaceous annuals or short-lived plants. Thus, Cistaceae are atypical ECM hosts that are fundamentally different in their biology from trees that are the more typically studied ECM host plants. The Mediterranean region is the center of diversity for Cistaceae and the ectomycorrhizal fungi associated with Cistaceae hosts have primarily been studied in Europe, North Africa, and the Middle East. Mediterranean Cistaceae often host diverse communities of ECM fungi, but they also act as hosts for some ECM fungi that putatively show host-specificity or strong host preference for Cistaceae (including species of Hebeloma, Terfezia, and Tirmania). The ECM associations of Cistaceae in North America, however, remain highly understudied. Here we use fungal DNA metabarcoding to document the ectomycorrhizal fungal communities associated with Crocanthemum and Lechea (Cistaceae) in open, fire-prone sandhill habitats in north Florida. At each site we also sampled nearby Pinus to determine whether small, herbaceous Cistaceae have specialized ECM fungi or whether they share their ECM fungal community with nearby pines. The ECM communities of Florida Cistaceae are dominated by Cenococcum (Ascomycota) and Russula (Basidiomycota) species but were also significantly associated with Delastria, an understudied genus of truffle-like Pezizales (Ascopmycota). Although many Cistaceae ECM fungi were shared with neighboring pines, the ECM communities with Cistaceae were nonetheless significantly different than those of pines.
- Brogin Van Skoik
Department of Science and Mathematics, Morris CollegePresence of Myxomycetes in a Southern Bottomland Hardwood Swamp in South Carolina
The presence of Myxomycetes in Southern Bottomland Hardwood Swamps is understudied and not well known. Several substrates were sampled to search for the presence of myxomycetes in a Southern Bottomland Hardwood Swamp. Tree bark, Bryophyte (mosses and liverworts) mats found on trees, and leaf litter found in the water were collected from Sparkleberry Swamp located in the midlands of South Carolina. The presence of six species of myxomycetes was determined with collections of substrates incubated using the moist chamber culture method. Twenty-one of the fifty cultures (42%) collected from tree bark/Bryophytes had the presence of fruiting bodies or plasmodium of myxomycetes. Four of the 15 cultures (26%) collected from leaf litter in the water had the presence of fruiting bodies or plasmodium of myxomycetes. This data provides evidence for the presence of myxomycetes in Southern Bottomland Harwood Swamps, but species richness and abundance are yet to be determined.
- Audrey Miller Williams, Claudia Petrucco, Julian Liber, Alex Crocker, and Amy S. GladfelterPhysiological adaptation to changing environments by the polyextremotolerant yeast Aureobasidium pullulans
Fungal life is found across a vast range of environments with extremes of pH, temperature, salinity, water availability, and other abiotic factors. Some fungi (termed polyextremotolerant), can grow in multiple extreme (as well as not-so-extreme) environments, and must adapt their physiology dramatically to maintain cell function in the face of these changes. A number of cellular adaptation mechanisms have been described, including changes in solute production, cell wall thickness, ion transport, membrane composition, and cell shape. However, we do not understand how these responses work together to sustain cell organization and biochemistry, the timescales on which different cellular adaptations occur, or how cells adapt to simultaneous changes in multiple environment features. To address these questions, we are developing the widespread, polyextremotolerant yeast Aureobasidium pullulans as a cell-biological model of adaptation to extremes. We are building a toolkit of genetically-encoded fluorescent probes with which to measure physiological and morphological traits including intracellular pH, ATP concentration, macromolecular crowding, and cell and vacuole size and shape. With these probes, we will compare the physiology of cells adapted to a range of temperatures, pH, and salinity, and map the dynamic responses of these cells to changes in these factors. We have also found that different A. pullulans isolates vary widely in their tolerance for high salinity and other culture conditions. We are sequencing the genomes of 200 isolates to identify genomic loci that correlate with the isolates’ ability to grow in different environments. We will draw on these data to identify new candidate cellular processes that contribute to adaptation to extremes.
- Caroline West, Abigail Leavitt LaBella, UNC CharlotteUnderstanding tRNA patterns and their nearby genes
Transfer RNA (tRNA) is a small RNA structure of around 90 nucleotides folded into a clover leaf structure that brings amino acids to mRNA during translation. On the chromosome, tRNA genes tend to cluster in particular regions, sometimes with multiple copies of the same tRNA. This leads to the question of how can the tRNA patterns impact gene expression outside the regular tRNA role in translation and what types of genes are located near tRNAs? The purpose of this work is to examine these interactions with the y1000 yeast genome files and analyze the genes closest to tRNAs to better understand how tRNA gene position correlates to gene expression.