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ABSTRACT Specific interactions between bacteria and ectomycorrhizal fungi (EcMF) can benefit plant health, and saprotrophic soil fungi represent a potentially antagonistic guild to these mutualisms. Yet there is little field‐derived experimental evidence showing how the relationship among these three organismal groups manifests across time. To bridge this knowledge gap, we experimentally reduced EcMF in forest soils and monitored both bacterial and fungal soil communities over the course of a year. Our analyses demonstrate that soil trenching shifts the community composition of fungal communities towards a greater abundance of taxa with saprotrophic traits, and this shift is linked to a decrease in both EcMF and a common ectomycorrhizal helper bacterial genus, Burkholderia, in a time‐dependent manner. These results not only reveal the temporal nature of a widespread tripartite symbiosis between bacteria, EcMF and a shared host tree, but they also refine our understanding of the commonly referenced ‘Gadgil effect’ by illustrating the cascading effects of EcMF suppression and implicating soil saprotrophic fungi as potential antagonists on bacterial‐EcMF interactions. [ABSTRACT FROM AUTHOR]

Decreasing returns in resource acquisition ability with increasing leaf mass investment is called 'diminishing returns', which provides important insights into plant economy. Yet, whether this is true for fine roots and how root resource acquisition strategies change with forest succession remain unclear.We investigated the scaling relationship between fine‐root length (L) and mass (M) for 215 topsoil cores from 24 plots across four successional stages in tropical forests of Xishuangbanna, southwestern China. We also assessed the relative effects of edaphic conditions, leaf functional traits, tree species diversity and soil fungal factors on L versus M scaling relationship using hierarchical variation partitioning.Our results revealed the existence of diminishing returns in root length (L vs. M scaling exponent <1), and that the exponent was higher in late‐ than early‐successional forests, corresponding to a strategy shifting from 'do‐it‐yourself' in the late‐successional stage to 'outsourcing' resource uptake by soil fungi in the early‐successional stage. Soil fungal abundance was the main driver of changes in the L versus M scaling exponent across plots (explained 58% of variances), with root endophytic fungi the strongest predictor (22.11%), followed by mycorrhizal fungi (10.41%), while other factors (leaf functional traits, edaphic nutrient conditions and tree species diversity) exerted weak effects.Our results suggest that root endophytic and mycorrhizal fungi act as key modulators of root economy changes during forest succession, but the former has received less attention previously. L versus M scaling exponent may be a better indicator for shifts in root resource acquisition strategy than the commonly used specific root length. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Background: Interactions between plants and diverse root-associated fungi are essential drivers of forest ecosystem dynamics. The symbiosis is potentially dependent on multiple ecological factors/processes such as host/symbiont specificity, background soil microbiome, inter-root dispersal of symbionts, and fungus–fungus interactions within roots. Nonetheless, it has remained a major challenge to reveal the mechanisms by which those multiple factors/processes determine the assembly of root-associated fungal communities. Based on the framework of joint species distribution modeling, we examined 1,615 root-tips samples collected in a cool-temperate forest to reveal how root-associated fungal community structure was collectively formed through filtering by host plants, associations with background soil fungi, spatial autocorrelation, and symbiont–symbiont interactions. In addition, to detect fungi that drive the assembly of the entire root-associated fungal community, we inferred networks of direct fungus–fungus associations by a statistical modeling that could account for implicit environmental effects. Results: The fine-scale community structure of root-associated fungi were best explained by the statistical model including the four ecological factors/processes. Meanwhile, among partial models, those including background soil fungal community structure and within-root fungus–fungus interactions showed the highest performance. When fine-root distributions were examined, ectomycorrhizal fungi tended to show stronger associations with background soil community structure and spatially autocorrelated patterns than other fungal guilds. In contrast, the distributions of root-endophytic fungi were inferred to depend greatly on fungus–fungus interactions. An additional statistical analysis further suggested that some endophytic fungi, such as Phialocephala and Leptodontidium, were placed at the core positions within the web of direct associations with other root-associated fungi. Conclusion: By applying emerging statistical frameworks to intensive datasets of root-associated fungal communities, we demonstrated background soil fungal community structure and fungus–fungus associations within roots, as well as filtering by host plants and spatial autocorrelation in ecological processes, could collectively drive the assembly of root-associated fungi. We also found that basic assembly rules could differ between mycorrhizal and endophytic fungi, both of which were major components of forest ecosystems. Consequently, knowledge of how multiple ecological factors/processes differentially drive the assembly of multiple fungal guilds is indispensable for comprehensively understanding the mechanisms by which terrestrial ecosystem dynamics are organized by plant–fungal symbiosis. [ABSTRACT FROM AUTHOR]

While the positive species–area relationship on islands is frequently observed, the mechanisms underlying this pattern remain poorly studied. By analyzing insular community diversity across spatial scales and the soil properties within the islands, we were able to explore potential mechanisms leading to the island species–area relationship of plants, as well as associated soil bacteria and fungi, from a tropical archipelago. We found that both plant and soil microbial communities showed similar positive species–area relationships across scales and the greater taxonomic diversity on larger islands was mainly driven by the higher richness within samples. These patterns arose primarily due to shifting habitat quality with island area, rather than spatial processes generally attributed to species–area relationships. Specifically, for plants, changes in soil total phosphorus content with island area were most explanatory, while changes in soil pH appeared to play the most important role in shaping soil bacteria and fungi patterns. By contrast, we found little evidence for the role of spatial processes (i.e. dispersal limitation or soil heterogeneity) within the island. Overall, this study highlights the importance of dissecting potential mechanisms underlying multi‐trophic community dynamics to explain patterns of biodiversity and its variation on islands. [ABSTRACT FROM AUTHOR]

Rainforests provide vital ecosystem services that are underpinned by plant-soil interactions. The forests of Borneo are globally important reservoirs of biodiversity and carbon, but a significant proportion of the forest that remains after large-scale agricultural conversion has been extensively modified due to timber harvest. We have limited understanding of how selective logging affects ecosystem functions including biogeochemical cycles driven by soil microbes. In this study, we sampled soil from logging gaps and co-located intact lowland dipterocarp rainforest in Borneo. We characterised soil bacterial and fungal communities and physicochemical properties and determined soil functioning in terms of enzyme activity, nutrient supply rates, and microbial heterotrophic respiration. Soil microbial biomass, alpha diversity, and most soil properties and functions were resistant to logging. However, we found logging significantly shifted soil bacterial and fungal community composition, reduced the abundance of ectomycorrhizal fungi, increased the abundance of arbuscular mycorrhizal fungi, and reduced soil inorganic phosphorous concentration and nitrate supply rate, suggesting some downregulation of nutrient cycling. Within gaps, canopy openness was negatively related to ectomycorrhizal abundance and phosphomonoesterase activity and positively related to ammonium supply rate, suggesting control on soil phosphorus and nitrogen cycles via functional shifts in fungal communities. We found some evidence for reduced soil heterotrophic respiration with greater logging disturbance. Overall, our results demonstrate that while many soil microbial community attributes, soil properties, and functions may be resistant to selective logging, logging can significantly impact the composition and abundance of key soil microbial groups linked to the regulation of vital nutrient and carbon cycles in tropical forests. [ABSTRACT FROM AUTHOR]

Background Aims Methods Results Conclusions The by‐product of insect larval production, frass, can be applied to soil as an organic fertiliser. Its three main organic N fractions are assumed to be ureic, protein and chitin. The significance of the latter is unknown, and it is not known if lignaceous sources have been overlooked.This study sought to gauge the activities of the (respectively, lignolytic and chitinolytic) enzymes peroxidase and N‐acetyl‐ß‐D‐glucosaminidase following frass application to soil. Their activities were monitored under conditions of urease inhibition, with a particular focus on the fungal domain.Mealworm or buffalo worm frass was applied, with or without inhibitors, to a sand/soil substrate at 3% (w/w). After 16 weeks, concentrations of the fungal biomarker ergosterol and enzyme activities were determined.Soil amendment with frass had no significant effect on peroxidase activity. Fungal biomass was stimulated in particular by application of mealworm frass, which was further improved by urease inhibition. Chitinase activity was positively correlated with fungal biomass, and was increased under urease inhibition when applied with mealworm frass.There were no appreciable quantities of lignaceous compounds in the frass used in this study. Importantly, the use of urease inhibitors co‐applied with frass has demonstrated that when its ureic N breakdown is prevented, chitin becomes a significant organic N source to soil fungi. The superior fungal response to mealworm frass indicates a larger chitin content than in buffalo worm frass. [ABSTRACT FROM AUTHOR]

Coccidioidomycosis is a disease caused by soil fungi of the genus Coccidioides, divided genetically into Coccidioides immitis (California isolates) and Coccidioides posadasii (isolates outside California). Coccidioidomycosis is transmitted through the inhalation of fungal spores, arthroconidia, which can cause disease in susceptible mammalian hosts, including humans. Coccidioidomycosis is endemic to the western part of the United States of America, including the central valley of California, Arizona, New Mexico, and parts of western Texas. Cases have been reported in other regions in different states, and endemic pockets are present in these states. The incidence of reported cases of coccidioidomycosis has notably increased since it became reportable in 1995. Clinically, the infection ranges from asymptomatic to fatal disease due to pneumonia or disseminated states. The recognition of coccidioidomycosis can be challenging, as it frequently mimics bacterial community-acquired pneumonia. The diagnosis of coccidioidomycosis is frequently dependent on serologic testing, the results of which can take several days or longer to obtain. Coccidioidomycosis continues to present challenges for clinicians, and suspected cases can be easily missed. The challenges of coccidioidomycosis disease, from presentation to diagnosis to treatment, remain a hurdle for clinicians, and further research is needed to address these challenges. [ABSTRACT FROM AUTHOR]

The proliferation of alien species that can suppress resident species via biotic interactions represents a growing concern worldwide. Yet, how above‐ and below‐ground communities simultaneously respond to plant invasion, particularly across large spatial scales, remains poorly explored. We hypothesized plant invasion has a greater impact on recipient above‐ and below‐ground communities at lower than higher latitudes given that biotic interactions play a more significant role in shaping communities in more favourable, lower latitude environments.To test this hypothesis, we conducted a comprehensive field survey of 124 sites spanning a 1700‐km latitudinal gradient in China, to explore the effects of invasion of Alternanthera philoxeroides, a globally widespread invasive plant, on plant, soil fungal and above‐ground arthropod communities.Invasion of A. philoxeroides had divergent effects on beta diversity (i.e. variation in taxa composition among sites) of plants, above‐ground arthropods and soil saprotrophic fungi, with negative, neutral and positive responses, respectively. Notably, the compositional dissimilarity of plant and arthropod communities between adjacent invaded and non‐invaded sites remained constant across latitudes. In contrast, the compositional dissimilarity of the entire and pathogenic fungal communities between adjacent invaded and non‐invaded sites increased with latitude. This resulted in a decreasing difference in invasion effects on the composition of plant and fungal communities with increasing latitude.Synthesis. Our study provides novel insights into the complexities of invasion effects by revealing contrasting responses of above‐ and below‐ground communities to plant invasion across latitudes. The contrasting responses could weaken or reshape above‐ and below‐ground interactions, and, in turn, affect future species invasions and the functioning of terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Military sites, both active and decommissioned, are rarely studied and may represent a source of fungal bioresources with potential applications for the remediation of co-contaminated soils. The aims of this study were both deepening the knowledge on fungal communities of a decommissioned military site and identifying indigenous bioresources showing potentialities for downstream mycoremediation applications. The culturable fractions of soil fungal communities of an Italian decommissioned military site were isolated from six representative sampling plots. In addition, the fungal community of the rhizosphere of Plantago lanceolata was also isolated. α and β diversity indices were used to analyze biodiversity data of the isolated fungal communities. A polycyclic aromatic hydrocarbons (PAHs) enrichment microplate experiment in the presence of Zn, Pb, and Zn-Pb co-contamination was conducted, followed by in vitro functional traits screenings, to select the isolates with the best potential for future mycoremediation applications. Globally 101 taxa, accounting for a total of 546 strains, were isolated from the samples. The enrichment results highlighted several fungal species showing the ability to use PAHs as nutritional source, even in the co-presence of potentially toxic elements. Finally, the analysis of their functional traits revealed their potential for biotechnological applications in soil detoxification. [ABSTRACT FROM AUTHOR]

Background: Talaromyces species play an important role in the nutrient cycle in natural ecosystems, degradation of vegetal biomass in industries and the implications in medicine. However, the species diversity of this genus is still far from fully understood. Methods: The polyphasic taxonomic approach integrating morphological comparisons and molecular phylogenetic analyses based on BenA, CaM, Rpb2 and ITS sequences was used to propose three new Talaromyces species. Results: Three new species of sect. Talaromyces isolated from soil are proposed, namely, T. disparis (ex-type AS3.26221), T. funiformis (ex-type AS3.26220) and T. jianfengicus (ex-type AS3.26253). T. disparis is unique in low growth rate, velvety texture, limited to moderate sporulation, biverticillate, monoverticillate and irregular penicilli bearing a portion of abnormally large globose conidia, it has no close relatives in phylogeny. Being a member of T. pinophilus complex, T. funiformis produces mycelial funicles on Czapek yeast autolysate agar (CYA), 5% malt extract agar (MEA) and yeast extract (YES), sparse sporulation on Czapek agar (Cz), CYA, MEA and YES while abundant on oatmeal agar (OA), bearing appressed biverticillate penicilli and globose to pyriform conida with smooth to finely rough walls. T. jianfengicus belongs to T. verruculosus complex, is characterized by velvety colony texture with moderate to abundant elm-green conidia en masse, producing biverticillate penicilli, globose conidia with verrucose walls. Conclusion: It is now a common practice in establishing new species of Aspergillus, Penicillium and Talaromyces based on morphological characters and phylogenetic analyses of BenA, CaM, Rpb2 and ITS sequences. The proposal of the three novelties of Talaromyces in this article is not only supported by their morphological distinctiveness, but also confirmed by the phylogenetic analyses of the concatenated BenA-CaM-Rpb2 and BenA-CaM-ITS, as well as the individual BenA, CaM, Rpb2 and ITS sequence matrices. [ABSTRACT FROM AUTHOR]

Mountain regions play a crucial role in maintaining global biodiversity, with altitude exerting a significant influence on soil microbial diversity by altering plant diversity, soil nutrients, and microclimate. However, differences in microbial community composition between topsoil (0–10 cm deep) and subsoil (10–20 cm deep) remain poorly understood. Here, we aimed to assess soil microbial diversity, microbial network complexity, and microbial community assembly in the topsoil and subsoil layers of the dry–hot Jinsha River valley in southwestern China. Using high-throughput sequencing in soil samples collected along an altitudinal gradient, we found that bacterial diversity in topsoil decreased with increasing altitude, while bacterial diversity in subsoil showed no altitude-dependent changes. Fungal diversity in topsoil also varied with altitude, while subsoil fungal diversity showed no change. These findings suggest that microbial diversity in topsoil was more sensitive to changes in altitude than subsoil. Bacterial community assembly tended to be governed by stochastic processes, while fungal assembly was deterministic. Soil bacterial and fungal network complexity was enhanced with increasing altitude but reduced as diversity increased. Interestingly, the presence of woody plant species negatively affected bacterial and fungal community composition in both soil layers. Soil pH and water content also negatively affected microbial community composition, while organic carbon and total nitrogen positively influenced the microbial community composition. Simultaneously, herb and woody plant diversity mainly affected soil bacterial diversity in the topsoil and subsoil, respectively, while woody plant diversity mainly affected soil fungal diversity in subsoil and soil nutrients had more effect on soil fungal diversity. These findings suggest that altitude directly and indirectly affects microbial diversity in topsoil, subsequently influencing microbial diversity in subsoil through nutrient availability. [ABSTRACT FROM AUTHOR]

Leguminous Inga trees are thought to enhance soil carbon (C) accumulation following reforestation, through mostly unknown mechanisms. This study amplified soil DNA using the ITS1F and ITS4 primers for PCR and Illumina MiSeq methods to identify fungal taxa, and traditional C analysis methods to evaluate how planted 4-, 8-, and 11-year-old Inga punctata trees affected soil fungal community compositions and C utilization patterns compared to old-growth I. punctata trees and an adjacent unplanted pasture within the same reforestation zone in Monteverde, Costa Rica. Along the tree age gradient, the planted I. punctata trees enhanced the tree soil C capture capacity, as indicated by increased levels of soil biomass C, Respiration, and efficiency of organic C use (with lower qCO2 values), and development of increasingly more abundant, stable, and successionally developed fungal communities, including those associated with the decomposition of complex organic C compounds. The level and strength of differences coincided with differences in the time of separation between the pasture and tree age or between the different tree ages. Fungal taxa were also identified as potential indicators of the early and late stages of soil recovery. Thus, planting I. punctata should be part of future reforestation strategies used in this region of the Monteverde Cloud Forest in Costa Rica. [ABSTRACT FROM AUTHOR]

Introduction: Wetlands are ecosystems that have a significant impact on ecological services and are essential for the environment. With the impacts of rapid population growth, wetland reclamation, urbanization, and land use change, wetlands have undergo severe degradation or loss. However, the response of soil fungal communities to wetland degradation remains unknown. It is crucial to comprehend how the diversity and population dynamics of soil fungi respond to varying levels of degradation and ecological progression in the wetlands of the Songnen Plain. Methods: In this study, high-throughput sequencing technology to analyze the variety and abundance of soil fungi in the undegraded (UD), light degraded (LD), moderate degraded (MD), and severe degraded (SD) conditions in the Halahai Nature Reserve of Songnen Plain. This study also explored how these fungi are related to the soil's physicochemical properties in wetlands at various degradation levels. Results: The findings indicated that Basidiomycota and Ascomycota were the primary phyla in the Songnen Plain, with Ascomycota increasing and Basidiomycota decreasing as wetland degradation progressed. Significant differences were observed in soil organic carbon (SOC), total nitrogen (TN), and soil total potassium (TK) among the succession degradation stages. With the deterioration of the wetland, there was a pattern of the Shannon and Chao1 indices increasing and then decreasing. Non-metric Multidimensional Scaling (NMDS) analysis indicated that the fungal community structures of UD and LD were quite similar, whereas MD and SD exhibited more distinct differences in their fungal community compositions. Redundancy analysis (RDA) results indicated that Soil Water content (SWC) and total nitrogen (TN) were the primary environmental factors influencing the dominant fungal phylum. According to the FUNGuild prediction, Ectomycorrhizal and plant pathogens gradually declining with wetland degradation. Discussion: In general, our findings can offer theoretical support develop effective solutions for the preservation and rehabilitation of damaged wetlands. [ABSTRACT FROM AUTHOR]

Introduction: The Grain for Green Project (GGP) by the Chinese government was an important vegetation restoration project in ecologically fragile and severely degraded karst regions. Soil fungi play a facilitating role in the cycling of nutrients both above and below the ground, which is crucial for maintaining ecosystem function and stability. In karst regions, their role is particularly critical due to the unique geological and soil characteristics, as they mitigate soil erosion, enhance soil fertility, and promote vegetation growth. However, little is known about how the implementation of this project shifts the co-occurrence network topological features and assembly processes of karst soil fungi, which limits our further understanding of karst vegetation restoration. Methods: By using MiSeq high-throughput sequencing combined with null model analysis technology, we detected community diversity, composition, co-occurrence networks, and assembly mechanisms of soil fungi under three GGP patterns (crop, grassland, and plantation) in the southwestern karst region. Results: Ascomycota and Basidiomycota were the main fungal phyla in all the karst soils. Returning crop to plantation and grassland had no significant effect on a diversity of soil fungi (P > 0.05), but did significantly affect the b diversity (P = 0.001). Soil moisture and total nitrogen (TN) were the main factors affecting the community structure of soil fungi. Compared with crop, soil fungi networks in grassland and plantation exhibited a higher nodes, edges, degree, and relatively larger network size, indicating that vegetation restoration enhanced fungal interactions. The soil fungi networks in grassland and plantation were more connected than those in crop, implying that the interaction between species was further strengthened after returning the crop to plantation and grassland. In addition, null-model analysis showed that the assembly process of soil fungal communities from crop to grassland and plantation shifted from an undominant process to dispersal limitation. Discussion: These data indicated that GGP in karst region changed the composition and assembly mechanisms of the soil fungal community and enhanced the interaction between fungal species, which can contribute to a better understanding of the fungal mechanisms involved in the restoration of degraded karst soils through vegetation recovery. [ABSTRACT FROM AUTHOR]

Agricultural practices can affect the diversity and community structure of soil fungi. This study investigates the impact of long-term agricultural practices on soil fungal diversity in the Loess Plateau of northwestern China. Different tillage practices have been implemented for 13 years, and their impact on soil fungi is assessed using high-throughput Illumina Sequencing. This study found a total of 2071 fungal Amplicon Sequence Variants (ASVs), and these were assigned to 25 different phyla, 372 families, and 496 genera. The fungal communities were dominated by Ascomycota (52.1%), followed by Zygomycota (14.3%) and Basidiomycota (9.0%). In general, the soil exhibited higher fungal community abundance, richness, and diversity in winter than in summer. Notably, no-tillage or stubble retention resulted in greater diversity than conventional tillage, with no-tillage combined with stubble retention resulting in the highest fungal richness, diversity, and network complexity in both summer and winter. These findings indicate that no-tillage with stubble retention is beneficial for biological soil components, which favors the establishment of abundant and diverse soil fungal communities in the Loess Plateau of China. The present study expands the knowledge of fungal communities in agro-ecosystems and the long-term ecosystem benefits of tillage practices. [ABSTRACT FROM AUTHOR]

Knowledge is scarce to what extent environmental drivers and native symbiotic fungi in soil induce abrupt (short‐term), systemic (multiple traits), or specific (a subset of traits) shifts in C3 plants' ecophysiological/mycorrhizal responses. We cultivated an emblematic native C3 species (Capsicum annuum var. glabriusculum, "Chiltepín") to look at how the extreme heat of the Sonoran desert, sunlight regimes (low = 2, intermediate = 15, high = 46 mol m2 d−1) and density of native arbuscular mycorrhizal fungi in soil (low AMF = 1% v/v, high AMF = 100% v/v), drive shifts on mycorrhizal responses through multiple functional traits (106 traits). The warming thresholds were relentlessly harsh even under intensive shade (e.g. superheat maximum thresholds reached ranged between 47–63°C), and several pivotal traits were synergistically driven by AMF (e.g. photosynthetic capacity, biomass gain/allometry, and mycorrhizal colonization traits); whereas concurrently, sunlight regimes promoted most (76%) alterations in functional acclimation traits in the short‐term and opposite directions (e.g. survival, phenology, photosynthetic, carbon/nitrogen economy). Multidimensional reduction analysis suggests that the AMF promotes a synergistic impact on plants' phenotypic integration and functional plasticity in response to sunlight regimes; however, complex relationships among traits suggest that phenotypic variation determines the robustness degree of ecophysiological/mycorrhizal phenotypes between/within environments. Photosynthetic canopy surface expansion, Rubisco activity, photosynthetic nitrogen allocation, carbon gain, and differential colonization traits could be central to plants' overall ecophysiological/mycorrhizal fitness strengthening. In conclusion, we found evidence that a strong combined effect among environmental factors in which AMF are key effectors could drive important trade‐offs on plants' ecophysiological/mycorrhizal fitness in the short term. [ABSTRACT FROM AUTHOR]

This study addresses the challenge of finding novel ways to solubilize phosphorus and zinc for agricultural purposes. The aim was to isolate PSMs (phosphorous-solubilizing microbes) and ZnSMs (zinc-solubilizing microbes) from different environments (e.g., soil amendments, land uses, and crop rotation systems) and evaluate their ability to solubilize different insoluble P sources (e.g., β-tricalcium phosphate (β-TCP), calcium-phytate (CaP), and rock phosphate (RP)) and Zn sources (e.g., zinc carbonate (ZnC), zinc oxide (ZnO), and zinc phosphate (ZnP)). Here, 25 isolates capable of solubilizing either P or Zn sources were isolated and classified by species using 16S rRNA and ITS-region sequencing. Notably, Aspergillus awamori, Fusarium circinatum, Fusarium longifundum, and Mucor circinelloides, isolated from cultivated soils and soil amendments, emerged as the most efficient PSMs and ZnSMs. Mucor circinelloides exhibited the highest solubilization ability for broths containing β-TCP, CaP, RP, ZnO, and ZnP, with log2-fold changes of 3.7, 1.8, 8.9, 7.8, and 2.4, respectively, compared to the control. For ZnC and ZnO, Aspergillus awamori displayed the highest Zn solubilization, with a 2.1 and 3.0 log2-fold change. The study highlights the potential of these strains as biofertilizers and underscores the role of Mucor and Fusarium genera in zinc solubilization. [ABSTRACT FROM AUTHOR]

Soil is an environment for huge diversity of fungi, which fulfill various tasks and support the maintaining of soil health. At the same time, varieties of soil fungal species, which produce numerous airborne spores and a range of mycotoxins, are known to be pathogenic for human health. The present review aims to summarize the current knowledge on soil fungi causing public health problems, including dermatoses, allergies, pulmonary diseases, wound infections, infections of the central nervous system, etc. [ABSTRACT FROM AUTHOR]

The general lack of knowledge on the conditions of Western Siberia (Omsk region) and the taxonomic diversity of zonal soils determines the relevance of these studies. The research was carried out in order to study the effect of complex biologics on the taxonomic diversity of the fungal component of the microbiome of the rhizosphere of cereals and the phytosanitary condition of crops in the southern forest-steppe (meadow-chernozem soil) and subtaiga (gray forest soil) zones of the Omsk Irtysh region (Western Siberia). This work was carried out in 2022–2023, using laboratory studies in combination with field experiments and metagenomic and statistical analyses. The objects of research were varieties of cereals and grain forage crops of Omsk selection: soil microorganisms. The scheme of the experiment involved the study of the following options: varieties of cereals (factor A): spring soft wheat—Omsk 42, Omsk 44, Tarskaya 12; durum wheat—Omsk coral; barley—Omsk 101; oats—Siberian hercules; bacterial preparation for seed inoculation (factor B) without the drug—Mizorin and Flavobacterin. The sampling of the plant rhizosphere for metagenomic analysis was carried out during the earing phase (July). For the first time, the taxonomic composition of the fungal community was determined based on the analysis of amplicon libraries of fragments of ribosomal operons of ITS2 fungi during colonization of crop roots by nitrogen-fixing bacteria in various soil and climatic zones of the Omsk region. The fungal component of the microbiome was analyzed in two zones of the Omsk region (southern forest-steppe and subtaiga). The five dominant phyla of soil fungi were located in the following decreasing series: Ascomycota (about 70%) > Mortierellomycota (about 7%) > Basidiomycota (about 5%) > Mucoromycota (3%) > Chytridiomycota (1%). The five main genera of fungi inhabiting the rhizosphere of cereals are located in a decreasing row: Giberella (6.9%) > Mortierella (6.6%) > Chaetomium (4.8%) > Cladosporium (3.8%) > Rhizopus (3.3%). The predominantly positive effect of biologics of associative nitrogen fixation on the fungal community of the soil (rhizosphere) of experimental sites located in different soil and climatic zones has been established. During seed bacterization, the growth of saprotrophic fungal genera was noted in relation to the control variants Pseudogymnoascus, Chloridium, Clonostachys, Trihoderma, etc., and the fungicidal properties of bacterial strains introduced into the soil were actively manifested relative to phytopathogenic fungi of the genera Alternaria, Blumeria, Fusarium, etc. According to the results of determining the number of infectious structures of Rhizoctonia solani, it was found that the population of the soil with viable cells of this pathogen was 1–3 pcs/g (below the threshold of harmfulness, PV 20 pcs/g of soil), which indicates a favorable phytosanitary situation with respect to the pathogen. The fungicidal effect of the applied bacterial fertilizers on Rhizoctonia solani could not be detected. The number of Bipolaris sorokiniana varied depending on the drug used. In the conditions of the southern forest-steppe zone of the Omsk region (meadow-chernozem soil), the greatest fungicidal effect was noted in Flavobacterin application variants on wheat of the Omsk 42 variety, durum wheat of the Omsk coral variety, and barley; the decrease in conidia relative to the control was 73, 35, and 29%, respectively. In the subtaiga zone of the Omsk Irtysh region (gray forest soil), as in the southern forest-steppe zone, pre-sowing bacterization of seeds with Flavobacterin led to a decrease in Bipolaris sorokiniana in the rhizosphere of wheat of the Omsk 42 variety by 18%, and oats by 27%, to control. The use of the drug Mizorin in some variants of the experiment led to an insignificant decrease in the harmful fungus or had no effect at all. [ABSTRACT FROM AUTHOR]

Greipsson, S.; Stover, K.; Whitney, S., and McElroy, T., 2024. Arbuscular mycorrhizal fungi and soil fungi associated with Uniola paniculata L. (sea oats) on restored and natural sand dunes on the Georgia Coast, U.S.A. Journal of Coastal Research, 40(5), 875–886. Charlotte (North Carolina), ISSN 0749-0208. Coastal sand dunes are fragile ecosystems that serve as natural defenses to protect barrier islands and the adjacent mainland during severe storms. A high frequency of disturbances may result in dune erosion. Several strategies have been used for coastal restoration; however, previous practices often lack the connection between plants and below-ground microbial communities. Symbiotic arbuscular mycorrhizal fungi (AMF) are beneficial in supplying a range of limiting nutrients to the host plant while improving dune stability. This study assessed the diversity of the indigenous AMF and soil fungal communities associated with Uniola paniculata L. (sea oats) on natural dunes and restored dunes at Jekyll and Tybee Islands on U.S. Georgia's coast. The phosphorus (P) concentrations of dune sand were also analyzed. At each site, samples were collected from 10 dune ridges that were randomly selected along a 100-m transect where sea oats were growing. The genomic DNA was extracted from 60 sand and sea oats root samples. A total of 13 amplicon sequence variants of AMF were identified; seven were classifiable to the species level. The most abundant genera of AMF were Glomus; the most abundant species were unclassified Glomus spp., followed by Glomus custos and G. deserticola. Using the Sorensen-Dice coefficient, the study showed that AMF assemblages of the natural dunes of both sites shared a high similarity (0.73). However, AMF assemblages of the Jekyll Island natural site had no (0) similarity to Jekyll Island restored site 1. The greatest number of classes of soil fungi were found at Jekyll Island's restored site 1 (18 classes); conversely, the lowest number was found at Jekyll Island's natural site (nine classes). Natural dunes contained significantly greater levels of P in the sand compared with restored dunes. These findings demonstrate the need to manage sand material and AMF assemblages during coastal dune restoration. [ABSTRACT FROM AUTHOR]

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Four novel macrocyclic trichothecenes, termed mytoxins D−G (1 − 4), along with four known analogs (5 − 8), were isolated from the ethyl acetate extract of fermented rice inoculated with the fungus Myrothecium verrucaria PA57. Each compound features a tricyclic 12,13-epoxytrichothec-9-ene (EPT) core. Notably, mytoxin G (4) represents the first instance of a macrocyclic trichothecene incorporating a glucosyl unit within the trichothecene structure. The structures of the newly identified compounds were elucidated through comprehensive spectroscopic analysis combined with quantum chemical calculations. All isolated compounds demonstrated cytotoxic activity against the CAL27 and HCT116 cell lines, which are models for human oral squamous cell carcinoma and colorectal cancer, respectively. Specifically, mytoxin D (1) and mytoxin F (3) exhibited pronounced cytotoxic effects against both cancer cell lines, with IC 50 values ranging from 3 to 6 nmol·L−1. Moreover, compounds 1 and 3 were found to induce apoptosis in HCT116 cells by activating caspase-3. [ABSTRACT FROM AUTHOR]

Purpose: Manganese (Mn) is crucial in low concentrations but can become toxic in soils and sediments, affecting plants and animals. Understanding how plants inoculated with arbuscular mycorrhizal fungi (AMF) tolerate Mn is crucial for the application of these microorganisms in the remediation of contaminated soils. Despite recognized benefits in various plant species, assessing plant-AMF interaction effectiveness in mitigating Mn toxicity is crucial for undocumented plants. Methods: Acacia mangium Willd. plants were inoculated with an AMF native to a Mn mining area and grown in soil with increasing Mn levels (0, 200, and 400 mg kg−1) to evaluate the effects of inoculation on plant growth and plant-AMF association strategies to reduce Mn toxicity. Results: Inoculation with AMF resulted in beneficial effects, minimizing Mn toxicity and enhancing plant growth, despite reduced mycorrhizal colonization and AMF spore levels in the soil. Non-inoculated plants exposed to 400 mg kg−1 of Mn exhibited significant reductions in shoot dry mass (64.9%), number of leaves (25%), and root length (24%) compared to AMF-inoculated plants. Mn concentration was higher in the roots of AMF-inoculated plants at all Mn levels, indicating a restriction in Mn transport to the shoot, thus minimizing damage and promoting plant growth. Energy-dispersive spectroscopy identified Mn, potassium, phosphorus, iron and calcium in AMF spores, suggesting their protective role against Mn phytotoxicity and adaptability of this species of microorganism under stress conditions. Conclusion: The native AMF inoculation reduces toxicity and improves the growth of A. mangium Willd. under high levels of Mn in the soil. [ABSTRACT FROM AUTHOR]

Abstract Background Metabarcoding targeting the internal transcribed spacer (ITS) region is commonly used to characterize fungal communities of various environments. Given their size and complexity, raw ITS sequences are necessarily processed and quality-filtered with bioinformatic pipelines. However, such pipelines are not yet standardized, especially for fungal communities, and those available may produce contrasting results. While some pipelines cluster sequences based on a specified percentage of base pair similarity into operational taxonomic units (OTUs), others utilize denoising techniques to infer amplicon sequencing variants (ASVs). While ASVs are now considered a more accurate representation of taxonomic diversity for prokaryote communities based on 16S rRNA amplicon sequencing, the applicability of this method for fungal ITS sequences is still debated. Results Here we compared the performance of two commonly used pipelines DADA2 (inferring ASVs) and mothur (clustering OTUs) on fungal metabarcoding sequences originating from two different environmental sample types (fresh bovine feces and pasture soil). At a 99% OTU similarity threshold, mothur consistently identified a higher fungal richness compared to DADA2. In addition, mothur generated homogenous relative abundances across multiple technical replicates (n = 18), while DADA2 results for the same replicates were highly heterogeneous. Conclusions Our study highlights a potential pipeline-associated bias in fungal metabarcoding data analysis of environmental samples. Based on the homogeneity of relative abundances across replicates and the capacity to detect OTUs/ASVs, we suggest using OTU clustering with a similarity of 97% as the most appropriate option for processing fungal metabarcoding data.

Abstract Paphiopedilum armeniacum, Paphiopedilum wenshanense and Paphiopedilum emersonii are critically endangered wild orchids. Their populations are under severe threat, with a dramatic decline in the number of their natural distribution sites. Ex situ conservation and artificial breeding are the keys to maintaining the population to ensure the success of ex situ conservation and field return in the future. The habitat characteristics and soil nutrient information of the last remaining wild distribution sites of the three species were studied. ITS high-throughput sequencing was used to reveal the composition and structure of the soil fungal community, analyze its diversity and functional characteristics, and reveal its relationship with soil nutrients. The three species preferred to grow on low-lying, ventilated and shaded declivities with good water drainage. There were significant differences in soil alkali-hydrolyzed nitrogen and available phosphorus among the three species. There were 336 fungal species detected in the samples. On average, there were different dominant groups in the soil fungal communities of the three species. The functional groups of soil fungi within their habitats were dominated by saprophytic fungi and ectomycorrhizae, with significant differences in diversity and structure. The co-occurrence network of habitat soil fungi was mainly positive. Soil pH significantly affected soil fungal diversity within their habitats of the three paphiopedilum species. The study confirmed that the dominant groups of soil fungi were significantly correlated with soil nutrients. The three species exhibit comparable habitat inclinations, yet they display substantial variations in the composition, structure, and diversity of soil fungi. The fungal functional group is characterized by a rich presence of saprophytic fungi, a proliferation of ectomycorrhizae, and a modest occurrence of orchid mycorrhizae. The symbiotic interactions among the soil fungi associated with these three species are well-coordinated, enhancing their resilience against challenging environmental conditions. There is a significant correlation between soil environmental factors and the composition of soil fungal communities, with pH emerging as a pivotal factor regulating fungal diversity. Our research into the habitat traits and soil fungal ecosystems of the three wild Paphiopedilum species has established a cornerstone for prospective ex situ conservation measures and the eventual reestablishment of these species in their native landscapes.

Soil is an environment for huge diversity of fungi, which fulfill various tasks and support the maintaining of soil health. At the same time, varieties of soil fungal species, which produce numerous airborne spores and a range of mycotoxins, are known to be pathogenic for human health. The present review aims to summarize the current knowledge on soil fungi causing public health problems, including dermatoses, allergies, pulmonary diseases, wound infections, infections of the central nervous system, etc.

Abstract Biological agents are getting a noticeable concern as efficient eco-friendly method for nanoparticle fabrication, from which fungi considered promising agents in this field. In the current study, two fungal species (Embellisia spp. and Gymnoascus spp.) were isolated from the desert soil in Saudi Arabia and identified using 18S rRNA gene sequencing then used as bio-mediator for the fabrication of silver nanoparticles (AgNPs). Myco-synthesized AgNPs were characterized using UV–visible spectrometry, transmission electron microscopy, Fourier transform infrared spectroscopy and dynamic light scattering techniques. Their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were investigated. In atrial to detect their possible antibacterial mechanism, Sodium dodecyl sulfate (SDS-PAGE) and TEM analysis were performed for Klebsiella pneumoniae treated by the myco-synthesized AgNPs. Detected properties of the fabricated materials indicated the ability of both tested fungal strains in successful fabrication of AgNPs having same range of mean size diameters and varied PDI. The efficiency of Embellisia spp. in providing AgNPs with higher antibacterial activity compared to Gymnoascus spp. was reported however, both indicated antibacterial efficacy. Variations in the protein profile of K. pneumoniae after treatments and ultrastructural changes were observed. Current outcomes suggested applying of fungi as direct, simple and sustainable approach in providing efficient AgNPs.

Molecular techniques for studying soil microorganisms allow to quantify the presence of specific functional groups from the total soil DNA and thus to assess their dynamic in response to the land use. Using this approach, a study was carried out to assess the increase the soil organic carbon (C) of arable land in the central Po Valley with three woody species (white willow, black locust, hybrid poplar) in short rotation forestry. Being fungi the most involved microorganisms in the C-cycle and representing the larger part of microbial biomass in volume, total fungi e the two most widespread main fungal degraders in the upper soil layer (Ascomycetes and Basidiomycetes) were used as indicators of the effectiveness of land use in increasing soil organic C. An innovative molecular technique (SYBR® Green I dye on the QuantStudio™ 3D digital PCR system) which allows to overcome the critical issues associated with the relatively low concentration of fungal DNA compared to that of bacteria was used. Compared to the ploughed soil, total organic carbon (TOC), microbial biomass and enzyme activities increased significantly in the woody plantations. However, TOC increased to different degrees among the woody species. White willow and black locust showed a greater increase in soil TOC than arable (+30 and 20% respectively), followed by hybrid poplar with a smaller increase of +12%. The increases in soil TOC in the three plantations were not correlated with the total woody mass, assessed 15 years after abandonment. Total fungi and Ascomycetes were highly correlated with microbial biomass and TOC, while Basidiomycetes were not. Ascomycetes, which commonly prevail in agricultural soils, were still the most abundant even after a short rotation forest cycle of 15 years and can be taken as good indicator of C sequestration activities into the soil. Soil tillage strongly reduced the content of Basidiomycetes and short rotation forestry managed to increase it at least 4-5 times over a 15-year cycle of short rotation forestry, suggesting that it can act as a qualitative indicator of C sequestration. Since Basidiomycetes have different biological and morphological characteristics than Ascomycetes, combining them (i.e., as Ascomicetes:Basidiomycetes ratio) seems to be a good option for choosing the most suitable woody species for carbon accumulation in agricultural soils.

Abstract Background Crop-associated microorganisms play a crucial role in soil nutrient cycling, and crop growth, and health. Fine-scale patterns in soil microbial community diversity and composition are commonly regulated by plant species or genotype. Despite extensive reports in different crop or its cultivar effects on the microbial community, it is uncertain how rhizoma peanut (RP, Arachis glabrata Benth.), a perennial warm-season legume forage that is well-adapted in the southern USA, affects soil microbial community across different cultivars. Results This study explored the influence of seven different RP cultivars on the taxonomic composition, diversity, and functional groups of soil fungal communities through a field trial in Marianna, Florida, Southern USA, using next-generation sequencing technique. Our results showed that the taxonomic diversity and composition of the fungal community differed significantly across RP cultivars. Alpha diversity (Shannon, Simpson, and Pielou’s evenness) was significantly higher in Ecoturf but lower in UF_Peace and Florigraze compared to other cultivars (p

Background: Phylogeographic studies have gained prominence in linking past geological events to the distribution patterns of biodiversity, primarily in mountainous regions. However, such studies often focus on plant taxa, neglecting the intricate biogeographical patterns of microbes, particularly soil microbial communities. This article explores the spatial distribution of the nematode-trapping fungus Arthrobotrys oligospora, a widespread microorganism, in a tectonically active region at the southeastern edge of the Qinghai-Tibetan Plateau. By analysing the genetic variation of this fungus alongside the historical structure of major river watersheds, we sought to uncover potential connections between the two. Our study involved sampling 149 strains from 116 sites across six major watersheds in the region. Results: The resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise. Conclusions: These findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution. [ABSTRACT FROM AUTHOR]

Till now, the diversity of entomopathogenic fungi in subtropical mountain forest was less studied. Here, the vertical distribution of forest soil fungi, entomopathogenic fungi, and their environmental influencing factors in a subtropical mountain in western China were investigated. Soil samples were collected from four elevations in a subtropical forest in Shaanxi. The results indicated a greater richness of soil fungi at middle elevations and soil fungi were more even at low elevation. Soil pH, available iron, available potassium, total potassium, and available zinc were the most important influencing factors affecting this vertical distribution of fungi. Interestingly, the Isaria genus was predominant while Metarhizium and Beauveria showed decreasing abundance. The presence of Isaria showed a significant positive correlation with both total phosphorus and available iron, while, available zinc was negatively correlated. Metarhizium was influenced by elevation, pH, available phosphorus, and available copper and Beauveria was influenced by soil organic carbon, total nitrogen, total potassium, available potassium, and available zinc. Overall, as environmental factors affecting soil fungi, elevation, and plant species diversity were less important than soil physical and chemical properties. The virulence of isolated entomopathogenic fungi were tested against larvae of Tenebrio molitor, with mortality ranging from 31.11% to 100%. The above findings provide valuable data to deepen our understanding of the diversity of entomopathogenic fungi in subtropical mountain forests. [ABSTRACT FROM AUTHOR]

The microbial communities in rhizosphere soil play important roles in plant health and crop productivity. However, the microbial community structure of rhizosphere soil still remains unclear. In this study, the composition, diversity and function of the microbial communities in the rhizosphere soil of healthy and diseased plants were compared using Illumina MiSeq high-throughput sequencing. The Sobs (richness) and Shannon (diversity) indices of the soil microbial communities were higher in the rhizospheres of 2- and 3-year-old susceptible plants than in those of the healthy plants. With the increase in planting time, the numbers of fungi tended to decrease, while those of the bacteria tended to increase. Fungal diversity could be used as a biological indicator to measure the health of Knoxia roxburghii. The microbial composition and differential analyses revealed that the rhizosphere soil infested with fungi had a higher relative abundance at the phylum level in Ascomycota and Basidiomycota, while the bacteria had a higher relative abundance of Chloroflexi and a lower relative abundance of Actinobacteriota. At the genus level, the rhizosphere soil infested with fungi had relatively more abundant unclassified_f__Didymellaceae and Solicoccozyma and relatively less abundant Saitozyma and Penicillium. The bacterial genus norank_f__Gemmatimonadaceae was the most abundant, while Arthrobacter was less abundant. In addition, the abundance of Fusarium in the fungal community varied (p = 0.001). It tended to increase in parallel with the planting years. Therefore, it was hypothesized that the change in the community composition of Fusarium may be the primary reason for the occurrence of root rot in K. roxburghii, and the change in the abundance of Fusarium OTU1450 may be an indication of the occurrence of root rot in this species. The community function and prediction analyses showed that the pathogenic fungi increased with the increase in planting years. In general, soil fungi can be roughly divided into three types, including pathotrophs, symbiotrophs, and saprotrophs. An analysis of the differences in the prediction of different rhizosphere functions showed that D and L were significantly different in the COG enrichment pathway of the K. roxburghii rhizosphere bacteria (p < 0.05). The soil physical and chemical properties, including the pH, AK, total potassium (TK), and catalase (S_CAT), had the most significant effect on the soil fungal community, and most of the soil physical and chemical properties significantly correlated with the bacterial community. This study demonstrated that the occurrence of root rot had an important effect on the diversity, structure and composition of microbial communities. In addition, the results will provide a theoretical basis to prevent and control root rot in K. roxburghii. [ABSTRACT FROM AUTHOR]

Ginkgo biloba is abundant in secondary metabolites, including flavonoids and terpenoids. While the majority of research has focused on the role of these compounds in disease resistance, their specific contribution to pathogen defense has been rarely explored. In this study, we collected root exudates from hydroponically cultivated ginkgo seedlings and conducted a metabolomic analysis. We identified several primary metabolites mainly comprising amino acids and nucleotides, while secondary metabolites consisted of various compounds, including bioactive compounds such as flavonoids and terpenoids. Focusing on the secondary metabolites with relatively higher abundance in the exudates, we selected a mixture of flavonoids and terpenoids for in vitro inhibition experiments against two soil-borne fungal pathogens, Fusarium oxysporum f. sp. cucumerinum that causes cucumber wilt and Rhizoctonia solani AG-8 that causes wheat root rot. The results indicated that the growth rate of both fungus cells was significantly reduced with the increasing concentration of the flavonoid and terpenoid mixture extracted from ginkgo and was completely inhibited at a concentration of 5 mg/mL. Further experiments revealed that this mixture of flavonoids and terpenoids had a destructive effect on the cellular structure of both fungi, thereby reducing cell viability and achieving an antifungal effect. These findings provide a foundation for further research into the use of ginkgo extracts in biological control. [ABSTRACT FROM AUTHOR]

It is generally recognized that the quality differences in plant germplasm resources are genetically determined, and that only a good "pedigree" can have good quality. Ecological memory of plants and rhizosphere soil fungi provides a new perspective to understand this phenomenon. Here, we selected 45 tea tree germplasm resources and analyzed the rhizosphere soil fungi, nutrient content and tea quality. We found that the ecological memory of tea trees for soil fungi led to the recruitment and aggregation of dominant fungal populations that were similar across tea tree varieties, differing only in the number of fungi. We performed continuous simulation and validation to identify four characteristic fungal genera that determined the quality differences. Further analysis showed that the greater the recruitment and aggregation of Saitozyma and Archaeorhizomyces by tea trees, the greater the rejection of Chaetomium and Trechispora, the higher the available nutrient content in the soil and the better the tea quality. In summary, our study presents a new perspective, showing that ecological memory between tea trees and rhizosphere soil fungi leads to differences in plants' ability to recruit and aggregate characteristic fungi, which is one of the most important determinants of tea quality. The artificial inoculation of rhizosphere fungi may reconstruct the ecological memory of tea trees and substantially improve their quality. [ABSTRACT FROM AUTHOR]

Canopy gaps can result in abiotic heterogeneities and diverse niches from gap borders to centers, potentially affecting fine root decompositions mediated by soil fungal communities. Despite extensive discussions on the relationship between soil fungi and fine root decomposition, the mechanism by which gap locations regulate fine root decomposition through the soil fungal community remains elusive. Here, we conducted an in situ field decomposition experiment of Chinese Toon (Toona sinensis) fine roots in a low-efficiency weeping cypress (Cupressus funebris) plantation forest across three microhabitats: gap centers, gap borders, and closed canopy areas. Soil fungal communities were determined using internal transcribed spacer (ITS) sequencing after two years of field incubation. Results showed that soil properties and nutrient content in residual roots varied across the three microhabitats, with the gap borders exhibiting the highest decomposition rates. While fungal α-diversity remained relatively consistent, taxonomic compositions differed significantly. Decomposition rates did not show significant correlations with soil properties, observed fungal ASVs, or overall community composition. However, they positively correlated with the relative abundance of saprotrophic Sordariomycetes, which in turn positively correlated with soil total nitrogen (with a highest correlation), peaking at the gap borders. Overall community variations were primarily driven by soil temperature and magnesium content in residual roots. Further analysis revealed high fungal community similarities and low dispersal limitations between the gap borders and closed canopy areas, with more phylogenetically clustered communities at the borders. These results demonstrate that the gap borders possess a high decomposition rate, likely due to the centralization of functions driven by soil fungi such as saprotrophs existing in the "microbial seed bank" or migrating from closed canopy areas. These findings highlight the key role of soil fungi, especially saprotrophic fungi, in fine root decomposition at the gap borders, stressing the importance of soil fungi-driven mechanisms in nutrient cycling, and also informing sustainable forest management practices. [ABSTRACT FROM AUTHOR]

Plastic mulch plays a crucial role in agricultural production in arid and semi-arid regions, positively impacting crop yields, salt suppression, and seedling protection. However, as the usage of plastic mulch extends over time, residue accumulation becomes a significant issue in these regions. To clarify the effects of plastic mulch residue on soil fungi, this study focused on three typical cotton-growing areas in Xinjiang. Using high-throughput sequencing technology, the study analyzed the changes in the fungal community structure and diversity in rhizosphere and non-rhizosphere soils across 27 cotton fields under three different levels of plastic mulch residue: 0–75 kg/ha, 75–150 kg/ha, and 150–225 kg/ha. The results indicated that Ascomycota and Basidiomycota were the dominant fungal phyla across all treatments. Increasing levels of plastic mulch residue reduced the fungal richness in the soil, with a greater effects observed on rhizosphere fungi compared to bulk soil fungi. The α-diversity of cotton rhizosphere fungi showed an increasing trend, followed by a decrease with increasing plastic mulch residue, in Aksu and Bazhou, peaking at 75–150 kg/ha. Conversely, in Changji, the α-diversity decreased with increasing plastic mulch residue. The α-diversity of non-rhizosphere fungi associated with cotton decreased with increasing plastic mulch residue. Plastic mulch residue significantly altered the soil fungal α-diversity and had a greater effects on rhizosphere fungi. Different levels of plastic mulch residue had varying effects on the β-diversity of rhizosphere and non-rhizosphere fungi, significantly influencing rhizosphere fungi in Aksu and Bazhou and non-rhizosphere fungi in Changji and Bazhou. Overall, different levels of plastic mulch residue exerted varying degrees of influence on the community composition and diversity of soil fungi associated with cotton, potentially reducing the fungal richness and altering the community structure with increasing residue levels. [ABSTRACT FROM AUTHOR]

Overgrazing and climate change are the main causes of grassland degradation, and grazing exclusion is one of the most common measures for restoring degraded grasslands worldwide. Soil fungi can respond rapidly to environmental stresses, but the response of different grassland types to grazing control has not been uniformly determined. Three grassland types (temperate desert, temperate steppe grassland, and mountain meadow) that were closed for grazing exclusion for 9 years were used to study the effects of grazing exclusion on soil nutrients as well as fungal community structure in the three grassland types. The results showed that (1) in the 0-5cm soil layer, grazing exclusion significantly affected the soil water content of the three grassland types (P < 0.05), and the pH, total phosphorous (TP), and nitrogen-to-phosphorous ratio (N/P) changed significantly in all three grassland types (P < 0.05). Significant changes in soil nutrients in the 5-10cm soil layer after grazing exclusion occurred in the mountain meadow grasslands (P < 0.05), but not in the temperate desert and temperate steppe grasslands. (2) For the different grassland types, Archaeorhizomycetes was most abundant in the montane meadows, and Dothideomycetes was most abundant in the temperate desert grasslands and was significantly more abundant than in the remaining two grassland types (P < 0.05). Grazing exclusion led to insignificant changes in the dominant soil fungal phyla and a diversity, but significant changes in the b diversity of soil fungi (P < 0.05). (3) Grazing exclusion areas have higher mean clustering coefficients and modularity classes than grazing areas. In particular, the highest modularity class is found in temperate steppe grassland grazing exclusion areas. (4) We also found that pH is the main driving factor affecting soil fungal community structure, that plant coverage is a key environmental factor affecting soil community composition, and that grazing exclusion indirectly affects soil fungal communities by affecting soil nutrients. The above results suggest that grazing exclusion may regulate microbial ecological processes by changing the soil fungal b diversity in the three grassland types. Grazing exclusion is not conducive to the recovery of soil nutrients in areas with mountain grassland but improves the stability of soil fungi in temperate steppe grassland. Therefore, the type of degraded grassland should be considered when formulating suitable restoration programmes when grazing exclusion measures are implemented. The results of this study provide new insights into the response of soil fungal communities to grazing exclusion, providing a theoretical basis for themanagement of degraded grassland restoration. [ABSTRACT FROM AUTHOR]

A liquid digestate (LD) obtained from the anaerobic digestion of mixed organic waste was characterised and tested on the fungi Pleurotus eryngii, Irpex lacteus and Trametes versicolor. Aqueous mixtures of LD at doses of 0.5, 1 and 2% (v/v) were tested directly or after interaction with 5% (w/v) biochar (BC-LD) and/or 100 mg L−1 soil humic acid (HA-BC-LD and HA-LD). Total luminescence (TL) analysis of LD showed the presence of fluorophores typical of scarcely aromatic matter, while the Fourier transform infrared (FTIR) spectrum evidenced absorption bands typical of labile and non-condensed material. Some spectroscopic variations of the LD sample were observed after its interaction with the other materials. All LD treatments markedly promoted hyphal extension of P. eryngii whose growth rate increased up to 38% at the highest LD dose. The LD alone had no influence on the other fungi, whose growth was stimulated by some combinations of LD with the other materials. In facts, the growth rate of I. lacteus increased in BC-LD 1 and BC-LD 2 (P ≤ 0.05) and in all treatments with HA (up to 6% in HA-LD 2, P ≤ 0.01), while the growth of T. versicolor was promoted by HA-BC-LD 2 treatment (P ≤ 0.05) and slightly inhibited by all BC-LD combinations (up to 7% by BC-LD 1, P ≤ 0.05). The overall results obtained encourage the addition of LD to the soil and suggest a possible use of this material as substrate ingredient for the cultivation of edible mushrooms such as P. eryngii. [ABSTRACT FROM AUTHOR]

Climate warming is causing widespread deglaciation and pioneer soil formation over glacial deposits. Melting glaciers expose rocky terrain and glacial till sediment that is relatively low in biomass, oligotrophic, and depleted in nutrients. Following initial colonization by microorganisms, glacial till sediments accumulate organic carbon and nutrients over time. However, the mechanisms driving soil nutrient stabilization during early pedogenesis after glacial retreat remain unclear. Here, we traced amino acid uptake by microorganisms in recently deglaciated high-Arctic soils and show that fungi play a critical role in the initial stabilization of the assimilated carbon. Pioneer basidiomycete yeasts were among the predominant taxa responsible for carbon assimilation, which were associated with overall high amino acid use efficiency and reduced respiration. In intermediate-and late-stage soils, lichenized ascomycete fungi were prevalent, but bacteria increasingly dominated amino acid assimilation, with substantially decreased fungal:bacterial amino acid assimilation ratios and increased respiration. Together, these findings demonstrate that fungi are important drivers of pedogenesis in high-Arctic ecosystems that are currently subject to widespread deglaciation from global warming. [ABSTRACT FROM AUTHOR]

Herbivore-avoided plant patches are one of the initial characteristics of natural grassland degradation. These vegetation patches can intensify the spatial heterogeneity of soil nutrients within these grasslands. However, the effects of non-edible plant patches patches on the spatial heterogeneity of microorganisms have not been sufficiently studied in alpine meadows of the Qinghai-Tibetan Plateau, especially patches formed by herbaceous plants. To answer this question, soil nutrients, plant assembly, and microbial communities were measured inside, around, and outside of Artemisia smithii patches. These were 0 m (within the patch), 0-1 m (one meter from the edge of the patch), 1-2 m (two meters from the edge of the patch), 2-3 m (three meters from the edge of the patch), and >30 m (non-patch grassland more than thirty meters from the edge of the patch). Our results showed that A. smithii patches accumulated more aboveground biomass (AGB) within the patches (0 m), and formed fertile islands with the soil around the patches. Additionally, A. smithii patches increased soil bacterial diversity within (0 m) and around (0-1 m) the patches by primarily enriching copiotrophic bacteria (Actinobacteria), while the diversity of fungal communities increased mainly in the 0-1 m area but not within the patches. Bacterial community diversity was driven by pH, urease, nitrate nitrogen (NO3 -- N), and microbial biomass carbon (MBC). The contents of soil water (SWC), soil organic matter (SOM), urease, NO3--N, and MBC were the main factors influencing the diversity of the fungal community. This study elucidates the vegetation, nutrients, and microbial heterogeneity and their interrelationships, which are observed in fertile islands of herbivore-avoided plant patches in alpine meadows, and provides further insights into the spatial pattern of nutrients in patchy degraded grasslands. [ABSTRACT FROM AUTHOR]

The differences inmass loss of leaf litter are primarily thought to be driven by microbial activity, especially by fungi. However, the existence of such differences across large spatial scales has not been well explored in field studies and the underlying mechanisms of difference are still unclear, especially for the role of different fungal guilds in driving different mass losses. We conducted a 1-year decomposition study within each of four coastalwetlands inChina to test the difference inmass loss across a large spatial scale (ranging from 26° N to 41° N in latitude). In each wetland, six sites including three composed of P. australis and three composed of another dominant plant species typically in coastal ecosystems were selected. We used P. australis leaf litter as the standard decomposition material, placing it into litter bags with mesh sizes 1mm and 4 mm, respectively. Final litter mass loss was examined approximately after 3, 9 and 12months. The differentmass loss was quantified using additionalmass loss at P. australis sites compared to that at another species sites. We found that themass loss of leaf litter of P. australis showed a clear difference across multiple coastal wetlands only at later stages of decomposition, which was independent of mesofauna (mesh size) contribution to decomposition. Furthermore, the observed difference in mass loss was primarily attributed to the dissimilarities in initial soil fungal community, particularly the symbiotrophic fungi, rather than the soil bacterial community. Our results provide empirical evidence of a large-scale difference in mass loss in litter decomposition and have linked the observed difference to different soil fungal guilds. These results indicate that symbiotrophic fungi might play a direct or indirect role in driving difference inmass loss, which contributes to a better understanding and invites in-depth further investigation on the underlying microbe-driven mechanisms of the difference. [ABSTRACT FROM AUTHOR]

Biological agents are getting a noticeable concern as efficient eco-friendly method for nanoparticle fabrication, from which fungi considered promising agents in this field. In the current study, two fungal species (Embellisia spp. and Gymnoascus spp.) were isolated from the desert soil in Saudi Arabia and identified using 18S rRNA gene sequencing then used as bio-mediator for the fabrication of silver nanoparticles (AgNPs). Myco-synthesized AgNPs were characterized using UV–visible spectrometry, transmission electron microscopy, Fourier transform infrared spectroscopy and dynamic light scattering techniques. Their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were investigated. In atrial to detect their possible antibacterial mechanism, Sodium dodecyl sulfate (SDS-PAGE) and TEM analysis were performed for Klebsiella pneumoniae treated by the myco-synthesized AgNPs. Detected properties of the fabricated materials indicated the ability of both tested fungal strains in successful fabrication of AgNPs having same range of mean size diameters and varied PDI. The efficiency of Embellisia spp. in providing AgNPs with higher antibacterial activity compared to Gymnoascus spp. was reported however, both indicated antibacterial efficacy. Variations in the protein profile of K. pneumoniae after treatments and ultrastructural changes were observed. Current outcomes suggested applying of fungi as direct, simple and sustainable approach in providing efficient AgNPs. [ABSTRACT FROM AUTHOR]

Mycorrhizal symbiosis is the association between the roots of several plant species and soil fungi of the Glomeromycotina subphylum. This symbiosis plays a crucial role in plant growth, development, and defense; therefore, understanding the abundance and diversity of arbuscular mycorrhizal fungi (AMF) species associated with plants of economic importance is of utmost concern. The objective of this study was to compare the abundance and composition of AMF communities in two Annona muricata cultivation sites, and in propagated soil, under different agricultural practices. The first cultivation site is under technified management with periodic fertilization and irrigation (TS), while the second cultivation site is under agroecological management without fertilization, irrigation, and with the presence of livestock (non-technified site; NTS). The extracted spores from the collected samples and the trap cultures were taxonomically identified based on their morphology. 13 species associated with A. muricata belonging to seven genera were identified in soil samples. The most abundant species were Funneliformis geosporum, Acaulospora kentinensis and Rhizophagus intraradices with a relative abundance of 45.9, 19.0 and 15.8%, respectively. In the propagation substrates, only 69% of the AMF species found in the field were identified. 11 species of AMF were found in the site with non- technified agronomic management, while only five species were found in the technified site. [ABSTRACT FROM AUTHOR]

In the Antarctic territory, only 0.35% of its surface is ice-free. Fildes Bay is one of these notable areas, due to its geographical location and better environmental conditions when compared to the Antarctic continent. Fildes Bay is an ideal site for studying microorganisms, such as filamentous fungi (FF). FF develop unique biochemical pathways and biomolecules necessary for their survival. However, it is essential to know the diversity of FF to understand their biotechnological potential. The main objective of this study was to isolate and identify cultivable strains of filamentous fungi from soils in Fildes Bay (King George Island, Antarctica). Fourteen soil samples were collected from different sectors of Fildes Bay and underwent chemical analysis. Subsequently, samples were suspended in water and inoculated in three different culture media. FF were purified and identified according to classical taxonomy. The soils showed heterogeneous chemical composition and capacity to harbour FF. The soils of Fildes Bay have chemical properties similar to mineral soils, although variations in the C/N ratio and nutrients suggest external influences of natural origin. A total of 1756 FF were isolated, identifying the genera Cladosporium, Penicillium, Pseudogymnoascus, strains of the Mucoromycota division, and four other unidentified genera. The study highlights the ability of FF to adapt to extreme environmental conditions, as well as their biotechnological potential. This work represents the first large-scale report on the isolation of fungi in Fildes Bay, Antarctica. [ABSTRACT FROM AUTHOR]

Fungi are a good source for lead molecules in drug discovery and development. However, many compounds derived from fungi were not evaluated for their bioactivity against economic, agricultural, and public health pests. Twelve fungal secondary metabolites (1-12) were evaluated for herbicidal activity against Silybum marianum and insecticidal activity against Culex pipiens larvae. Among the tested metabolites, brefeldin A (6) and 6-eopxy-4-hydroxy-3-methoxy-5-methyl-cyclohex-2-en-1-one (11) showed potent herbicidal activity against S. marianum with complete inhibition of seed germination at 500 mg L-1. Compound 6 revealed an exceptional herbicidal activity as it caused complete inhibition of root growth and strong reduction in shoot growth (I = 74.5%) and germination (10.0%) at 25 mg L-1. In addition, dehydroaustin (9), phomaxanthone A (4) and deacetylphomaxanthone A (5) displayed a potent toxicity against fourth larval instar of C. pipiens with LC50 values of 3.27, 57.03 and 63.50 mg L-1, respectively. Based on the results of this study, compounds 4-6, 9 and 11 should be developed as natural pesticides. [ABSTRACT FROM AUTHOR]

We explored the activation of defense genes and the changes in volatile profiles in olive (Olea europaea var. Picual) plants subjected to mechanical wounding and prior soil inoculation with the fungus Trichoderma afroharzianum T22. Our findings indicate a sustained effect of the inoculant in olive plants, which shifted the constitutive volatile emission more significantly towards an aldehyde-dominated blend than the mechanical damage alone. Furthermore, we found that wounding alone did not alter the expression of hydroperoxide lyase genes associated with aldehyde biosynthesis. However, this expression was significantly enhanced when combined with prior T22 inoculation. Mechanical wounding amplified the plant's immediate defensive response by enhancing the upregulation of the direct defense enzyme acetone cyanohydrin lyase. Trichoderma afroharzianum T22 also modulated direct defense, although to a lesser extent, and its effect persisted 9 months after inoculation. Metagenomic analyses revealed that aerial mechanical damage did influence specific root bacterial functions. Specifically, an upregulation of predicted bacterial functions related to various metabolic processes, including responses to biotic and abiotic stresses, was observed. On the contrary, T22's impact on bacterial functional traits was minor and/or transient. [ABSTRACT FROM AUTHOR]

Planting native tree species plantations and Eucalyptus plantations is a common model of forest management in south subtropical China. To explore the response characteristics and mechanisms of soil fungal community diversity and function to native tree species and Eucalyptus plantations. four native tree species plantations(Pinus massoniana, Michelia macclurei, Mytilaria laosensis, Castanopsis hystrix)and exotic tree species Eucalyptus urophylla × E. grandis(EUG) plantations in south subtropical China were studied. Based on 18S rRNA high-throughput sequencing data of fungi in soil(0-20 cm)of each stand and FUNGuild database, the differences of diversity and functional group of soil fungal communities between native tree species and EUG plantations were compared and analyzed, as well as the dominant soil environmental factors affecting them. The results were as follows:(1)The dominant phyla of soil fungi in five stands were both Ascomycota and Basidiomycota, but there were differences in the dominant orders of soil fungi between different native tree species and EUG plantations. (2)The α diversity of soil fungal community in EUG plantation was higher than that in native tree plantations, and the community composition structure was significantly different from the native tree plantations(P<0.05). (3)The relative abundance of saprotroph in the native tree plantations was higher than that of EUG plantation, and the relative abundance of soil arbuscular mycorrhizal fungi in Michelia macclurei and Mytilaria laosensis plantations was significantly higher than that of EUG plantation. The relative abundance of soil symbiotroph, ectomycorrhizal fungi and wood saprotroph in EUG plantation was significantly higher than that in the native tree plantations. (4)pH was the crucial soil environmental factor that led to the difference of soil fungal community diversity and functional group between EUG and native tree plantations. In general, there were significant differences in the structure and function of soil fungal community between native tree species and EUG plantations, which indicated that different stand types had great effects on soil fungal community and function. In conclusion, the soil nutrient level can be improved by converting the EUG plantation into native tree species plantations in south subtropical China, and the soil ecological function can be improved by choosing Michelia macclurei plantation or Mytilaria laosensis plantation as native tree species plantation. [ABSTRACT FROM AUTHOR]

Although positive effects of arbuscular mycorrhizal (AM) fungi on plant performance under drought have been well documented, how AM fungi regulate soil functions and multifunctionality requires further investigation. In this study, we first performed a meta‐analysis to test the potential role of AM fungi in maintaining soil functions under drought. Then, we conducted a greenhouse experiment, using a pair of hyphal ingrowth cores to spatially separate the growth of AM fungal hyphae and plant roots, to further investigate the effects of AM fungi on soil multifunctionality and its resistance against drought. Our meta‐analysis showed that AM fungi promote multiple soil functions, including soil aggregation, microbial biomass and activities of soil enzymes related to nutrient cycling. The greenhouse experiment further demonstrated that AM fungi attenuate the negative impact of drought on these soil functions and thus multifunctionality, therefore, increasing their resistance against drought. Moreover, this buffering effect of AM fungi persists across different frequencies of water supply and plant species. These findings highlight the unique role of AM fungi in maintaining multiple soil functions by mitigating the negative impact of drought. Our study highlights the importance of AM fungi as a nature‐based solution to sustaining multiple soil functions in a world where drought events are intensifying. [ABSTRACT FROM AUTHOR]