Back

Fungal Ecology

Elsevier BV

Preprints posted in the last 30 days, ranked by how well they match Fungal Ecology's content profile, based on 12 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

1
Optimization of conidial production in the thermally dimorphic fungal pathogen Histoplasma

English, B. C.; Kalem, M. C.; Voorhies, M.; Sil, A.

2026-08-20 microbiology 10.64898/2026.08.20.745944 medRxiv
Top 0.1%
9.9%
Show abstract

Sporulation is an integral process in the lifecycle of many fungal pathogens, including Histoplasma, a primary human pathogen that causes respiratory infections. Histoplasma conidia, or asexual spores, are the primary infectious particle but very little is known about them, in part due to the need for Biosafety Level 3 containment and inconsistency in generating viable conidia under laboratory conditions. Here, we identify media that consistently promote Histoplasma conidiation, yielding both micro- and macroconidia, and conditions that promote high levels of germination. We show that conidiation media and duration affect the proportion of macroconidia produced, and we demonstrate that Histoplasma strains vary in their response to these conidiation parameters. Finally, imaging studies of chitin, exposed chitin, and cell wall mannoproteins show that while micro- and macroconidia have similar cell wall compositions, strain type and conidiation media variation result in qualitative differences in staining. These optimized methods for Histoplasma conidial preparations will enable more detailed investigations into this understudied aspect of the biology of an important human fungal pathogen.

2
High culturable diversity and climate-associated seasonal dynamics of Saccharomycotina yeasts in subtropical forest leaf litter

Chien, W.-T.; Yeh, Y.-C.; Yang, C.-J.; Liu, Y.-C.; Chen, H.; Sun, P.-W.; Tsai, C.-H.; Ke, P.-J.; Ting, C.-T.; Chang Yang, C.-H.; Tsai, I. J.

2026-08-26 microbiology 10.64898/2026.08.25.747014 medRxiv
Top 0.1%
6.1%
Show abstract

Forest-associated Saccharomycotina occur at low relative abundance, limiting inference about their diversity and dynamics. We sampled leaf litter weekly for 47 weeks across a subtropical forest in northern Taiwan. Enrichment, isolation and ITS sequencing recovered 687 isolates, including 613 Saccharomycotina representing 56 described species and 77 putatively novel operational taxonomic units. Rarefaction indicated unsampled culturable diversity. Among litter traps, community dissimilarity was high and dominated by taxon replacement, but neither topography nor geographic distance was associated with composition, and turnover matched randomised expectations. Richness peaked during warm, wet periods and declined in winter, and minimum temperature showed the strongest statistical association. Composition was associated with maximum temperature, minimum relative humidity, precipitation and solar radiation. Selected isolates' thermal optima covaried with collection-week temperatures, and two October Magnusiomyces magnusii isolates had higher optima than four winter isolates. Together, these findings reveal substantial culturable diversity and seasonal community restructuring consistent with temperature-related filtering.

3
Less is more? Faster growth is associated with lower ectomycorrhizal diversity in mature Picea glauca at the Alaskan treelines

Kuprina, K.; Basnet, S.; Bog, M.; Schnittler, M.

2026-08-21 ecology 10.64898/2026.08.20.745949 medRxiv
Top 0.1%
5.3%
Show abstract

Root-associated fungal (RAF) communities can influence tree nutrient acquisition and performance, yet their structuring factors and relationship with tree growth remain poorly understood, particularly near environmental treelines. We characterized root-associated fungal (RAF) communities on fine roots of white spruce (Picea glauca [Moench] Voss) in paired forest and treeline plots across two elevational and one moisture-limited treeline ecotones in Alaska. Using ITS2 DNA metabarcoding of fine root tips, we characterized individual RAF community alpha and beta diversity and tree growth based on basal area increment (BAI) over 5-30 years. As a result, sampling site was the strongest predictor of RAF composition, explaining 19.6% of variation, while soil pH explained an additional 11.7%. Treeline effects on RAF communities were weaker and context-dependent, with treeline trees showing distinct community composition in the Alaska Range, lower alpha diversity across all Hill numbers in Interior Alaska, and higher ECM relative abundance in the Brooks Range. RAF composition did not differ between fast- and slow-growing trees within sites. In contrast, alpha diversity was negatively associated with tree growth: OTU richness, Shannon and Inverted Simpson indices significantly predicted BAI over the previous 5, 10 and 15 years, with fast-growing trees supporting less diverse RAF and ECM communities. This relationship was strongest for recent growth and weakened with longer BAI averaging periods. Our results suggest that high growth of mature P. glauca is not necessarily associated with greater RAF or ECM diversity or specific taxa but may instead rely on fewer dominant or functionally effective fungal partners.

4
Biocontrol potential of endophytic bacteria against a collection of Leptosphaeria maculans isolates causing blackleg in oilseed rape

Stieben, M. E.; Rossi, F. R.; Garriz, A.; Romero, F. M.

2026-08-10 microbiology 10.64898/2026.08.10.743986 medRxiv
Top 0.1%
3.3%
Show abstract

BACKGROUNDBlackleg, caused by Leptosphaeria maculans, is a major disease limiting oilseed rape production worldwide, and its management increasingly requires sustainable alternatives to chemical fungicides. In this study, we evaluated the antagonistic activity and plant growth-promoting potential of three endophytic bacteria, Bacillus velezensis Bro5, Bacillus subtilis Bro11, and Pantoea agglomerans Bru13, against a geographically diverse collection of 139 L. maculans isolates from five oilseed rape-producing regions of Argentina. RESULTSDual culture assays revealed strong inhibitory activity by Bro5 and Bro11, with mean inhibition rates of [~]80% across isolates, while Bru13 showed variable inhibition (<75% for most isolates). Greenhouse and growth chamber assays confirmed the protective potential of these strains. At the cotyledon stage, Bro11 and Bro5 reduced lesion size by 47% and 28%, respectively, while their combination achieved a 51% reduction. In greenhouse trials, combined application of Bro5 and Bro11 reduced stem base necrosis by 45% and increased the proportion of plants with [&le;]50% damage to 98%, compared to only 70% in controls. Key disease metrics, including disease index, incidence, and severity, decreased by 60%, 23%, and 26%, respectively. Beyond pathogen suppression, inoculation with the Bro5-Bro11 consortium enhanced plant growth, increasing shoot biomass by 89% at early stages, and improving stem dry weight and diameter by 10% and 35%, respectively, at maturity. CONCLUSIONThese findings highlight the robustness of Bacillus endophytes as biocontrol agents, their capacity to suppress diverse pathogen isolates, and their dual role in plant growth promotion, supporting their potential integration into sustainable blackleg management programs.

5
Diffuse fungal symbiosis in Deathwatch beetles

Hendricks, A. A.; Phillips, T. K.; Engl, T.; Plarre, R.; Martinson, V.

2026-08-11 microbiology 10.64898/2026.08.10.743371 medRxiv
Top 0.1%
2.0%
Show abstract

Many insects rely on symbiotic fungi to occupy specialized ecological niches, yet the evolutionary dynamics of these partnerships remain poorly resolved for most lineages. The beetle family Ptinidae, split into the morphologically distinct Spider beetles and Deathwatch beetles, has long been known to harbor fungal endosymbionts based on early microscopy, but few associations have been confirmed with molecular methods. Here, we combined ultra-conserved element (UCE) phylogenomics with ITS amplicon sequencing to test whether fungal endosymbionts are conserved across Ptinidae and whether they have cospeciated with their hosts. Our UCE phylogeny supports Spider beetles and Deathwatch beetles as monophyletic clades but indicates that some aspects of subfamily-level taxonomy may merit closer examination. Screening for three known symbiotic fungal genera (Symbiotaphrina, Meyerozyma, Nakazawaea) revealed Symbiotaphrina in most Deathwatch beetles but no Spider beetles, while the other two genera were present but uncommon. Despite widespread Symbiotaphrina infection, we found no phylogenetic mirroring between host and symbiont trees, indicating an absence of codiversification. Instead, distantly related hosts frequently shared closely related symbionts, consistent with diffuse, mixed-mode transmission involving both vertical and horizontal symbiont exchange. This pattern parallels those documented in fungus-farming termites, ambrosia beetles, ants, and woodwasps, suggesting that diffuse, mixed-mode symbiosis may be a general hallmark of long-term insect-fungal associations. We further identify an unidentified Helotiales group as a candidate novel endosymbiont, recovered consistently within a clade comprising Anobium, Hemicoelus, and Ptilinus. Together, these findings reframe Deathwatch beetle-fungal associations as a dynamic, evolutionarily labile symbiosis rather than a fixed partnership.

6
Deadwood-related microhabitats in old-growth forests in Poland

Przepiora, F.; Ciach, M.

2026-08-13 ecology 10.64898/2026.08.12.744401 medRxiv
Top 0.1%
1.7%
Show abstract

Deadwood is a fundamental component of forest ecosystem, supporting biodiversity and driving multiple ecological processes. However, structures that may develop on downed coarse woody debris (CWD) create additional microhabitats that are used by numerous organisms and contribute to small-scale habitat heterogeneity. To date, quality of CWD is commonly characterized by its volume, diameter, tree species or stage of decomposition, while fine-scale structures occurring there remain not surveyed and their role in ecosystem is rarely quantified. Here, we introduce the novel concept of microhabitats on CWD. i.e. Deadwood-related Microhabitats (DreMs), defined as distinct features occurring on CWD that may provide shelter, breeding or foraging sites for forest-dwelling organisms. Using an original catalogue comprising 14 groups and 30 types, we inventoried DreMs on 6,003 CWD across 423 study plots located in best-preserved old-growth forests in Poland. We quantified the frequency and richness of DreMs and assessed the link between CWD characteristics and DreM richness in spruce, beech, willow-poplar, fir-beech and oak-lime- hornbeam forests. All inventoried DreMs occurred on both deciduous and coniferous taxa. The most frequent DreM included bryophyte mats, loose bark patches, insect galleries, fungal fruiting bodies and polypores. DreM richness increased with CWD diameter, more complex architecture and the presence of multiple decay classes within single debris. DreM richness peaked at intermediate decay classes and was higher on deciduous than on coniferous taxa. Our study is the first large-scale qualitative and quantitative assessment of DreMs in temperate forests. By focusing on forests characterized by ecological continuity and minimal human-related disturbance, the results provide a reference for downed deadwood-associated structures. By complementing inventory of tree-related microhabitats, DreMs extend potential monitoring schemes of habitat quality and contribute to biodiversity-oriented forest management. Highlights* Downed coarse woody debris (CWD) hosts Deadwood-related microhabitats (DreMs) * Higher DreM richness is associated with CWD diameter * DreM richness peak at intermediate stages of wood decay * CWD of deciduous taxa support more DreMs than coniferous * Diversified CWD and DreMs increase habitat heterogeneity for forest-dwelling taxa

7
Annual ploughing turns wildflower plantings into ecological traps for ground-nesting wild bees

Hellerich, C.; Klein, A.-M.; Garratt, M.; Mupepele, A.-C.; Fornoff, F.

2026-08-26 ecology 10.64898/2026.08.25.746958 medRxiv
Top 0.2%
1.1%
Show abstract

Wildflower plantings are an important conservation measure for supporting wild bee diversity. They aim to enhance floral resources for nutrition, but do not explicitly consider that bees also require suitable nesting and overwintering resources. Wildflower plantings may provide nesting habitat for ground-nesting bees, but the effects of soil management, e.g. ploughing, on ground-nesting bees are hardly known. To study how ploughing and age of wildflower plantings affect ground-nesting bees, we sampled bees on ploughed and unploughed wildflower plantings aged 0-4 years. We used emergence traps to sample bees directly after emergence from the ground, allowing inference on nest numbers. We found that ploughing and wildflower planting age negatively affected overwintering bee nest numbers. Nesting peaked in the year of wildflower planting establishment and declined thereafter, indicating lower habitat suitability at later successional stages. Annual ploughing caused the greatest reduction in nest numbers (-72 %), providing evidence for an ecological trap.

8
Plant-pollinator interactions along an elevational gradient in Central European forest understorey

Sounapoglou, A.; Janecek, S.; Sakhalkar, S. P.; Kobe, I. N.; Chmelova, E.; Anyz, D.; Delabye, S.; Filip, J.; Hodecek, J.; Jackwerth, K.; Piplova, R.; Hanzelkova, K.; Krizek, T.; Klomberg, Y.; Mertens, J. E. J.; Tropek, R.

2026-08-20 ecology 10.64898/2026.08.15.745048 medRxiv
Top 0.2%
1.1%
Show abstract

Elevational gradients provide a framework for understanding how environmental filtering reorganises communities and interactions, but plant-pollinator interactions along temperate forest elevational gradients remain overlooked. We studied early-spring understorey communities at four forest sites spanning the foothills towards the timberline (450-1,000 m a.s.l.) in the Krkono[s]e Mountains, Czechia. Across six transects per elevation, we quantified flowering plant species richness, floral resources and traits, and video-recorded flowers, yielding 4,003 pollinator visits. We analysed elevational patterns in species richness, community composition, floral traits, and quantitative network characteristics. Visitation frequency and flowering plant and pollinator species richness peaked at intermediate elevations. The contribution of dipteran relative to hymenopteran pollinators increased towards higher elevations, principally because of non-hoverfly flies, whereas individual bee groups showed no uniform response. Floral resources and traits showed no uniform elevational responses, although total nectar sugar availability peaked at the highest site because of the dominant Vaccinium myrtillus. Most notably, both network-level specialisation and mean species-level specialisation were generally greater at the two higher elevations, whereas nestedness was lower and other network characteristics showed no consistent patterns. These findings suggest that shifts in pollinator composition and dominant floral resources potentially shaped interactions along the gradient. The increasing specialisation with elevation contrasts with the generalisation often expected under reduced partner availability and indicates that forest networks may follow elevational patterns not predicted from open habitats. Despite limited site-level replication, this study provides, to our knowledge, the first community-wide characterisation of plant-pollinator interactions along a temperate forest elevational gradient and identifies patterns requiring evaluation across replicated gradients.

9
The impact of lure, trap type, and Fluon application on the capture of longhorned beetles (Coleoptera: Cerambycidae) in the subtropical forests of southeastern Louisiana, USA

Sharma, C.; Sheline, W.; Grossman, E.; Jean-Williams, N.; Macias-Samano, J.; Setter, R. R.; Johnson, T. D.

2026-08-19 ecology 10.64898/2026.08.18.745610 medRxiv
Top 0.2%
1.0%
Show abstract

The expansion of global trade has increased the risk of unintentional introductions of woodboring insects outside their native ranges, which can cause considerable ecological and economic damage. Monitoring efforts for native and non-native species of woodborers rely heavily on semiochemical-baited traps. With the goal of improving detection efforts of longhorned beetles (Coleoptera: Cerambycidae) and their associates, we conducted field bioassays in loblolly pine dominated and bottomland hardwood forest ecosystems, which are representative of subtropical Louisiana. We tested the impact of attractant composition, trap design, and the application of a friction reducing compound on the capture of longhorned beetles. We compared the Synergy Multi-Trap System with and without Fluon, and the Synergy Funnel Trap II with Fluon, baited with multicomponent cerambycid lures and ethanol or ethanol alone. In total, we collected 5,303 beetles comprising 44 species. Traps baited with cerambycid lures and ethanol captured ~11X more individuals than the traps baited with ethanol. We identified novel attractants for 6 species of longhorned beetles. When Fluon was applied, both the Synergy Multi-Trap System and Funnel Trap II were equally effective at capturing cerambycids. Application of Fluon significantly increased the trap capture of the Synergy Multi-Trap System by ~4X compared to the same trap type without Fluon. Our results contribute to our understanding of the factors influencing trap captures and the chemical ecology of woodboring insects thereby helping the development of early detection and rapid response monitoring programs in subtropical regions of the United States and elsewhere.

10
In Vivo Screening for a Promising Antiparasitic Agent Against Neobenedenia melleni in Epinephelus fuscoguttatusfemale x E. lanceolatusmale and Identification of Its Potential Target

Gao, L.; Wang, G.; Xu, J.; Guo, Y.; Luo, W.; Yan, Y.; Li, G.; Yu, Q.; Liu, M.; Wang, E.; Li, P.; Liu, T.

2026-08-25 zoology 10.64898/2026.08.24.746648 medRxiv
Top 0.2%
0.9%
Show abstract

Monogenean ectoparasites, particularly Neobenedenia species, cause severe economic losses in mariculture. Here, ectoparasites isolated from cultured hybrid groupers (Epinephelus fuscoguttatus[female] x E. lanceolatus[male]) were confirmed as Neobenedenia melleni based on ITS1 phylogeny. In vivo screening of six structurally diverse compounds identified compound D (CAS No. 206111-37-7), a 5,6-dihydropyridine derivative, as the most effective antiparasitic agent, achieving 76.54% efficacy at 0.5 mg/L in a 90 min bath treatment. Dose-response assays demonstrated that 0.7 mg/L compound D achieved 95.23% antiparasitic efficacy without causing evident tissue damage or cytotoxicity to GF-1 cells. Ultrastructural observation by scanning electron microscopy revealed marked tegumental alterations, including deep fissures and extensive surface folding, in treated parasites. Molecular docking against ten candidate proteins identified {beta}-tubulin as the most favorable docking target, with a binding energy of -6.53 kcal/mol and three hydrogen-bond interactions, suggesting that {beta}-tubulin may be involved in the antiparasitic activity of compound D. Overall, these findings highlight compound D as a promising lead candidate for short-bath therapy against N. melleni and suggest that cytoskeletal disruption through {beta}-tubulin interaction represents a plausible mechanism of action.

11
Effect of microampere-scale wireless conductive microelectrostimulation on Aspergillus fumigatus growth on solid cultures

Kambouris, M. E.; Kritikou, S.; Milioni, A.; Ludovici, G. M.; Karageorgou, K.; Velegraki, A.

2026-08-11 microbiology 10.64898/2026.08.10.743807 medRxiv
Top 0.2%
0.9%
Show abstract

The effect of microcurrents on facultative microbial pathogens remains controversial. Solid cultures in Sabouraud Glucose Agar of the ubiquitous mold Aspergillus fumigatus were repeatedly treated with a commercially available device performing wireless conductive microelectrostimulation by 3.5 A microcurrent routed by spraying negatively charged air particles onto solid cultures in modified petri dishes. The treated cultures displayed increased growth compared to standard ones, but only as a function of mycelial density and total surface; the radial growth rate of the mycelium remained unaltered. The increased growth was positively related to the duration of the treatment. At the same time, secondary development (new mycelial loci within the dish) was greatly upheld due to treatment, as the spraying created microairstreams dislocating the fungal spores. These results imply perplexed kinetics of mycelial growth both with and without treatment, since the folding of the mycelial mat is observed regularly. Both the fungus response to the ES and the possible revision of growth kinetics create prospects for biotechnological and bioremediation applications but also imply biomedical considerations, regarding infection dynamics of mycelial fungi and their in situ resistance to immune responses and treatment.

12
Strain-specific thermotolerance, UV-C tolerance, and biofilm formation on clinically relevant plastic substrates in the emerging opportunistic pathogen Rhodotorula mucilaginosa

Chen, Y.; Jimenez, I. A.; Casadevall, A.; Stempinski, P. R.

2026-08-20 microbiology 10.64898/2026.08.19.745829 medRxiv
Top 0.2%
0.8%
Show abstract

Rhodotorula mucilaginosa is an emerging opportunistic fungal pathogen increasingly associated with catheter-related bloodstream infections. Although biofilm formation is considered a major virulence trait for R. mucilaginosa, factors contributing to biofilm persistence on medical devices remain poorly understood. Here, we characterized the thermotolerance, biofilm formation, UV resistance, and cell surface hydrophobicity profiles of eight R. mucilaginosa strains representing clinical and non-clinical (laboratory, environmental, and marine mammal) isolates. All strains grew optimally at 30C and exhibited restricted growth at 35C and 37C, although one environmental isolate maintained robust growth at 37C. All strains exhibited moderate to high cell surface hydrophobicity. We then assessed biofilm formation for each strain, including adherence to two different plastic substrates, development of biofilm biomass, comparison of biofilm metabolic activity, and the effects of temperature on biofilm formation. Under static conditions, biofilm biomass of most isolates on 96-well polystyrene plates was greatest at 24C. Clinical isolates generally maintained higher biofilm metabolic activity at 37C than nonclinical isolates, while at lower temperatures, clinical and non-clinical isolates did not differ significantly in metabolic activity. All strains readily formed biofilms on polyurethane intravenous catheters under dynamic conditions, as confirmed by scanning electron microscopy and metabolic activity. While planktonic cells already displayed substantial UV-C tolerance, biofilm-associated cells remained viable following exposure to UV-C doses up to eightfold higher than those that impaired planktonic growth. These findings document differences in thermotolerance and biofilm formation by isolate origin and identify biofilm formation as a major factor promoting persistence of R. mucilaginosa on clinically relevant materials and reduced susceptibility to UV-C sterilization.

13
Undying leafcutter-ant colonies: The oldest Atta texana leafcutter-ant colonies are estimated to grow older than 100 years

Mueller, U. G.; Farrior, C. E.

2026-08-06 ecology 10.64898/2026.08.05.743090 medRxiv
Top 0.2%
0.8%
Show abstract

Tropical Atta leafcutter-ant colonies reach a maximum lifespan of 15-20 years because each colony has only a single queen, queens live for maximally 15-20 years, and colonies do not requeen after queen death. At the northern range limit of leafcutter ants in Louisiana, however, we found that the mortality rate of Atta texana colonies is consistent with a life expectancy of 65-75 years and a maximum colony lifespan exceeding 100 years. Annual mortality of established A. texana colonies in Louisiana is only 1-2% compared to 10-25% in tropical Atta species. Exceptional longevity of A. texana colonies is due to (i) absence of Nomamyrmex army-ant predators specialized to raid Atta colonies; (ii) polygyny of A. texana colonies, creating a unique social organization in A. texana colonies that differs from the monogynous colonies typical for all other Atta species; and (iii) adoption of young queens by old colonies, possibly facilitated by low genetic diversity in range-limit populations of A. texana. Centenarian longevity of A. texana colonies was so far unknown because, from the 1930s to the turn of the century, research prioritized eradication of A. texana as a forestry pest, and landscape-wide pesticide application by aircraft eliminated old A. texana colonies. After the most harmful pesticides were banned 30-50 years ago, A. texana populations recovered, yet A. texana required decades to regain its earlier niche in the forest ecology. In undisturbed habitat, well-established old A. texana colonies with large territories appear to recruit young queens especially well. Old age of a colony therefore does not necessarily increase mortality as in typical lifespan-limiting processes where age drives senescence and mortality (old age [-&gt;] mortality); instead, well-rooted residency that is correlated to age of an A. texana colony increases the chance of rejuvenation via queen adoption, reduces or eliminates reproductive senescence of a colony, and consequently prolongs colony lifespan (well-established residency [-&gt;] rejuvenation [-&gt;] long life). Large size attained in old age imparts potentially unending life.

14
Pathogen-dependent biocontrol activity of Chlorella sorokoniana aqueous extracts against fungal and oomycete plant pathogens

Ciubotaru, R. M.; Claro, M.; Viana, C.; Figueiras, R.; Rosa, P.; Duarte, B.; Charnobay, A. C. R.; Rato, C.; Tedesco, S.; Andrade, S.; Coelho, L.; Gama, F.; Reis, M.; Correia, S.; Azevedo, C.

2026-08-06 plant biology 10.64898/2026.08.05.742703 medRxiv
Top 0.2%
0.6%
Show abstract

Fungal and oomycete plant pathogens are major drivers of yield losses worldwide and are spurring the search for sustainable alternatives to synthetic pesticides. Algae, in general, and microalgae, in particular, represent a promising source of bioactive compounds for crop protection. Despite this, their efficacy across different host-pathogen systems remains poorly characterised. This study evaluated the biocontrol potential of the aqueous extract of Chlorella sorokoniana against three economically important phytopathogens using complementary in vitro, ex vivo, and in planta assays. The strongest activity was observed against Magnaporthe oryzae, with the extract reducing fungal growth by approximately 70% in vitro, inhibiting appressorium formation by 55%, suppressing lesion development on detached rice leaves by more than 75%, and reducing rice blast severity by 64.5% as a preventive foliar treatment. In contrast, the extract showed little or no direct in vitro antifungal activity against Pythium ultimum and Rhizoctonia solani, yet it significantly reduced disease severity in planta by 13-37% and 48-55%, respectively. The contrasting responses among pathosystems suggest that C. sorokoniana aqueous extracts act through different mechanisms depending on the pathogen and the crop, combining direct antifungal activity against M. oryzae with plant-associated protective effects against soil-borne pathogens. These findings highlight the importance of evaluating candidate biocontrol products using complementary in vitro and in planta approaches, as laboratory antimicrobial assays alone may substantially underestimate their agricultural potential. The broad-spectrum protection achieved with an unrefined aqueous extract further supports C. sorokoniana as a promising source of sustainable crop protection products and provides a strong foundation for future mechanistic studies, formulation development, and field validation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=115 SRC="FIGDIR/small/742703v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@394716org.highwire.dtl.DTLVardef@6a208corg.highwire.dtl.DTLVardef@17f0724org.highwire.dtl.DTLVardef@adda96_HPS_FORMAT_FIGEXP M_FIG C_FIG

15
Multidimensional host-associated diversification in natural Festuca_Epichloe festucae symbioses across the Iberian Peninsula

Sotomayor-Alge, A.; Nagabhyru, P.; VazquezdeAldana, B. R.; Inda, L. A.; Zabalgogeazcoa, I.; Schardl, C. L.; Catalan, P.

2026-08-22 evolutionary biology 10.64898/2026.08.22.746409 medRxiv
Top 0.2%
0.6%
Show abstract

Epichloe fungal endophytes form widespread symbioses with temperate grasses, yet the extent to which diversity within endophyte species is shaped by host association remains poorly understood. Here, we characterized naturally occurring Festuca_Epichloe symbioses across diverse Iberian ecosystems using an integrative framework combining ecological, cytogenetic, phenotypic, molecular and chemical analyses. Novel associations of Epichloe festucae with Festuca trichophylla, F. lambinonii and F. yvesii were documented, together with substantial variation in infection incidence and mating-type composition among host-associated populations. Morphological traits, vegetative growth and alkaloid profiles differentiated strains according to host identity. Furthermore, multilocus phylogenetic analyses assigned all fine-leaved Festuca host isolates to Epichloe festucae, but identified a recurrent host-associated genetic structure, along with a deeper evolutionary signal, that largely corresponds to the host phylogeny. By contrast, genome size estimates varied little among Epichloe festucae strains, with all isolates exhibiting haploid genomes. Alkaloid content across the four major classes of Epichloe compounds (pyrrolopyrazines, 1-aminopyrrolizidines, ergot alkaloids and indole-diterpenes) showed only partial concordance with the presence of biosynthetic genes, indicating that functional outcomes are influenced by regulatory and environmental factors beyond biosynthetic gene presence. Chemotypic profiles clearly differentiated Epichloe festucae from E. coenophiala while demonstrating considerable functional diversity among E. festucae strains. Collectively, these complementary datasets reveal two interconnected signatures of diversification: pervasive host-associated differentiation across multiple biological dimensions and a deeper historical signal retained in phylogenetic relationships. These findings provide a foundation for future genomic, evolutionary and systematic studies to determine whether these lineages represent ongoing fungal divergence and speciation

16
Nutrient Availability Regulates an Exploration-Elaboration Trade-off in Fungal Rhizomorph Networks

Naeher, S. C.; Buehler, M. J.

2026-08-24 bioengineering 10.64898/2026.08.23.746505 medRxiv
Top 0.2%
0.6%
Show abstract

Rhizomorphs are specialised, root-like fungal structures whose hierarchical organisation may offer a route to reinforcing mycelium-based materials, yet the environmental regulation of their network formation remains poorly understood. Here, we develop an image-based framework to characterise the longitudinal growth and organisation of Armillaria gallica rhizomorphs under varying nutrient availability and light exposure. Time-lapse imaging was combined with image segmentation, skeleton-based network analysis, optical measurements and Gompertz growth modelling. Nutrient availability produced a distinctly non-monotonic response. Moderate nutrient limitation (0.5 x standard concentration) favoured rapid and coherent exploratory growth, whereas intermediate enrichment (1.5 x) produced the greatest eventual network extent, reaching approximately 975 mm total strand length; network extent and radial expansion differed significantly across nutrient levels (padj = 0.0012). Further enrichment maintained substantial fungal coverage without additional network elaboration, consistent with a shift from long-range exploration towards more locally consolidating growth. By contrast, exclusion of ambient light produced no significant differences after multiple-testing correction. These results reveal a resource-dependent trade-off between exploration and network elaboration, demonstrate that fungal coverage and organised network formation are distinct outcomes, and provide a quantitative basis for controlling self-organised biological architectures for bio-derived material design.

17
Microbial Communities in Cave Waters Across Karst Regions of Virginia

Drake, R. S.; Kosic Ficco, K.; Malabad, T. E.; Orndorff, W.

2026-08-10 microbiology 10.64898/2026.08.09.738996 medRxiv
Top 0.3%
0.6%
Show abstract

Karst groundwater supplies in Virginia are relied on to varying degrees for domestic, agricultural, and municipal water supplies. Further, Virginian caves harbor an estimated 200 endemic invertebrate species. The microbial occupants of Virginias karst aquifers are largely undescribed; characterizing them promises to inform both the scientific description of these systems and the management of a critical water resource. Karst aquifers are heterogeneous, and much of the water moving through them cannot be reached directly; we profiled cave waters both because cave passages offer direct access to active groundwater and because cave water specifically is relied upon by endemic invertebrate species living in caves. Using 16S rRNA sequencing, we characterized aquatic microbial communities in eight Virginia caves, across Virginias four major karst regions. We identified 3,899 unique amplicon sequence variants (ASVs) and found that caves hosted diverse microbial assemblages that differed markedly among sampled sites. These baseline data provide a starting point for future work to understand how seasonal cycles, weather events, and surface disturbances affect the microbial communities present in cave waters and the cave-endemic invertebrates that depend on these waters.

18
Yield losses associated with peanut smut incidence in Argentina: a quantitative synthesis across field studies

Cazon, L. I.; Gonzalez, N. R.; Del Ponte, E. M.; Costa de Carvalho, A. C.; Asinari, F.; Camiletti, B. X.; Paredes, J. A.

2026-08-11 plant biology 10.64898/2026.08.11.744131 medRxiv
Top 0.3%
0.6%
Show abstract

Peanut smut, caused by Thecaphora frezzii, is an important constraint to peanut production in Argentina, but quantitative estimates of yield losses across environments remain limited. We quantified the relationship between disease incidence and kernel yield using 922 observations from 26 field studies conducted in Cordoba, Argentina, between 2021 and 2025. Study-specific incidence-yield relationships were analyzed using linear regression, random-effects meta-analysis, and linear mixed-effects models. Peanut smut incidence was consistently associated with yield reduction across studies. The estimated damage coefficient ranged from 24.2 to 28.7 kg ha-{superscript 1} per 1% increase in disease incidence, corresponding to a relative yield reduction of 0.74-0.87% of attainable yield. In contrast, attainable yield varied markedly among studies, ranging from 1,370 to 5,409 kg ha-{superscript 1}. Although an exploratory segmented analysis suggested a breakpoint near 12% incidence, subsequent moderator analyses, study- specific regressions, and normalized response curves provided no evidence of a biologically meaningful change in the damage coefficient across incidence or yield classes. These results indicate that differences among environments were primarily associated with attainable yield rather than with changes in the magnitude of disease-associated yield loss. The resulting damage function provides a quantitative basis for yield-loss assessment and disease management in peanut.

19
Metagenomic analysis of the effects of European bison Bison bonasus (Linnaeus, 1758) presence on soil community structure and function in West Blean and Thornden Woods, Kent

Xu, C.; Schalkwyk, H. V.; Powell, O.; Gustave, C.; Ball, L.; Ross, K.; Murray, E.; Aguirregoicoa, H.; Mackins, H.; Swinnerton, K.; Creedy, T. J.; Sivess, L.; Jones, J.; Castillo, K.; Bleet, R.; Salatino, S.; Mendis, Y.-T. C.; Lebre, P.; Mkrtchyan, H.; Cuber, P.

2026-08-20 ecology 10.64898/2026.08.19.745704 medRxiv
Top 0.3%
0.6%
Show abstract

The reintroduction of extinct or endangered species to restore ecosystem function is an essential aspect of rewilding. The Wilder Blean Project at West Blean and Thornden Woods in Canterbury, UK, is committed to rewilding natural processes and enhancing biodiversity in one of England's oldest and largest areas of ancient woodland. The introduction of European bison (Bison bonasus) is an important part of the project. However, how the reintroduction of large herbivores influences local biodiversity and ecosystem functions during the early stages of rewilding remains poorly understood. Soil samples were collected from the same sampling sites before and two years after bison were reintroduced and profiled by metagenomic sequencing using Oxford Nanopore Technologies sequencing platforms. The results showed that the alpha diversity of soil organisms did not change significantly before and after the introduction of European bison, while beta diversity showed modest shifts in community composition. The relative abundance of some nitrogen-fixing and photosynthetic microbial genera showed declines in the 2024 Bison Area, while the mycorrhizal fungus genus Rhizophagus was significantly less abundant than in the 2024 Control Area. Despite relatively stable taxonomic diversity, functional composition differed significantly between the 2022 and 2024 Bison areas and among the 2024 rewilding treatments, revealing a decoupling between taxonomic diversity and functional composition. Amino acid synthesis pathways and carbon metabolism pathways were significantly enriched. These findings highlight the potential of long-read Oxford Nanopore metagenomics to reveal functional shifts that may not be apparent from taxonomic diversity alone. Although these early-stage responses cannot yet predict long-term rewilding trajectories, continued longitudinal monitoring integrating microbial, soil physicochemical, and ecosystem-level measurements will be essential to determine the persistence and ecological significance of these functional shifts.

20
Stingless bees, turtle ants and tea plants are rich sources of undescribed Lactobacillaceae

Oliphant, S. A.; Gardner, J. M.; Jiranek, V.; Sumby, K. M.

2026-08-12 microbiology 10.64898/2026.08.12.744358 medRxiv
Top 0.3%
0.6%
Show abstract

Knowledge of the family Lactobacillaceae rests largely on isolates from foods and a few repeatedly sampled hosts. Reference databases give an unrecognised sequence the name of its nearest relative, so a lineage with no entry of its own is renamed rather than flagged. Here we classify the family across the public plant and invertebrate amplicon record to locate the hosts carrying undescribed lineages. Across 3,344 independent 16S rRNA gene amplicon studies, every sequence cluster was tested against a type-strain reference and placed at the deepest rank it supports. Of 204,813 classified clusters, 20,516 were named to species and 127,906 to genus, while 4,741 matched no described species. Six published datasets whose authors could name their Lactobacillaceae only as "Lactobacillus", or not at all, are reclassified here. Genera described from one habitat occur far beyond it, three bee-associated genera occurring on Rosaceae and Brassicaceae at several times their rate on wind-pollinated grasses, and we found no published Bombilactobacillus record from a plant. Undescribed lineages concentrate in the least-cultured hosts, reaching 86.1% and 77.4% of studies in the stingless bees Melipona and Tetragonula, and are most divergent in the turtle ant Cephalotes and, among plants, in tea, Camellia. An independent genome-resolved survey of pot honey converges on the same two genera. The primary descriptions of forty-eight species from these hosts specify a supplemented medium, so the hosts carrying undescribed lineages also indicate how to culture them.