Seasonal Succession of Fungal Communities in Native Truffle (Tuber indicum) Ecosystems.

Truffles are a rare underground fungus and one of the most expensive, and sought-after kitchen ingredients in the world. Microbial ecology plays an important role in the annual growth cycle of truffles, but fungal communities in native truffle ecosystems are still largely unknown, especially for Tuber indicum from China. In this study, the spatial and temporal dynamics of soil physicochemical properties and fungal communities were described associated with four T. indicum-producing plots (TPPs) and one non-truffle-producing plot in four successive growing seasons. A total of 160 biological samples were collected, 80 of which were used for the determination of 10 soil physicochemical indices and 80 for Illumina-based analysis of the fungal microbiome. Soil physicochemical properties and fungal communities exhibited considerable seasonal variation. Ascomycetes, Basidiomycetes, and Mucormycoides dominated. The core microbiome work on the microecological changes in TPPs, and the identified core members contribute to the seasonal succession of communities. The genus Tuber occupies a central position in healthy TPPs. There was a strong correlation between soil physicochemical properties and fungal communities. The genus Tuber showed a positive correlation with Ca, Mg, and total nitrogen, but a negative correlation with total phosphorus and available potassium. This study describes the complex ecological dynamics of soil physicochemical indices and fungal communities occurring during the annual cycle of Tuber indicum, and highlights the succession of core communities in truffle plots, which contribute to better protection of native truffle ecosystems and control of mycorrhizal fungal contamination in artificial truffle plantations in China. IMPORTANCE The spatial and temporal dynamics of soil physicochemical properties and fungal communities associated with four Tuber indicum-producing plots and one non truffle producing plot in four different growing seasons are described. Soil physicochemical properties and fungal communities exhibited considerable seasonal variation. This study examines the complex ecological dynamics of soil physicochemical indices and fungal communities occurring during the annual cycle of Tuber indicum and highlights the succession of core communities in truffle plots, which contributes to better protection of native truffle ecosystems and control of mycorrhizal fungal contamination in artificial truffle plantations in China.

Analysing sinonasal microbiota of fungal rhinosinusitis by next-generation sequencing.

OBJECTIVES: Fungal rhinosinusitis is an inflammatory disease of the nose that may lead to life-threatening complications. This study compared the bacterial and fungal microbiomes between patients with invasive fungal rhinosinusitis (IFRS) and non-IFRS (NIFRS). DESIGN: This was a prospective study including 18 IFRS and NIFRS patients. Fungal and bacterial microbiomes from surgical specimens were sequenced from amplicons of the internal transcribed spacer 1 (ITS1) region and the V3-V4 region of the 16S locus, respectively. Microbiomes were generated using the Illumina MiSeq System 2 x 301 base pair chemistry with a paired-end protocol. SETTING: Tertiary medical centre. RESULTS: Targeted metagenomics identified Aspergillus spp. as the predominant fungus in both IFRS and NIFRS patients. Based on phylum and genera level diversity, and abundance differences, significant differences of operational taxonomic units (OTUs) (Fusobacterium, Prevotella, Pseudomonas, Neisseria and Streptococcus) were more abundant in NIFRS compared with IFRS patients. CONCLUSIONS: This is the first study to analyse bacterial and fungal microbiomes in patients with IFRS and NIFRS via ITS1 and 16S genomics sequencing. Bacterial microbiomes from patients with IFRS demonstrated dysbiosis (alterations in diversity and abundance) compared to those from patients with NIFRS.

Orchid mycorrhizal fungi and ascomycetous fungi in epiphytic Vanda falcata roots occupy different niches during growth and development.

Epiphytic orchids are commonly found in exposed environments, which plausibly lead to different root fungal community structures from terrestrial orchids. Until recently, few studies have been conducted to show the fungal community structure during the growth of a photosynthetic and epiphytic orchid in its natural growing site. In this study, the Vanda falcata (commonly known as Neofinetia falcata), one of Japan's ornamental orchids, was used to characterize the fungal community structure at different developmental stages. Amplicon sequencing analysis showed that all development stages contain a similar fungal community: Ascomycota dominate half of the community while one-third of the community belongs to Basidiomycota. Rhizoctonia-like fungi, a polyphyletic basidiomycetous fungal group forming mycorrhizas in many orchids, exist even in a smaller portion (around one-quarter) compared to other Basidiomycota members. While ascomycetous fungi exhibit pathogenicity, two Ceratobasidium strains isolated from young and adult plants could initiate seed germination in vitro. It was also found that the colonization of mycorrhizal fungi was concentrated in a part of the root where it directly attaches to the phorophyte bark, while ascomycetous fungi were distributed in the velamen but never colonized cortical cells. Additionally, the root parts attached to the bark have denser exodermal passage cells, and these cells were only colonized by mycorrhizal fungi that further penetrated into the cortical area. Therefore, we confirmed a process that physical regulation of fungal entry to partition the ascomycetes and mycorrhizal fungi results in the balanced mycorrhizal symbiosis in this orchid.

Dysbiosis: An Indicator of COVID-19 Severity in Critically Ill Patients.

Here, we examined the dynamics of the gut and respiratory microbiomes in severe COVID-19 patients in need of mechanical ventilation in the intensive care unit (ICU). We recruited 85 critically ill patients (53 with COVID-19 and 32 without COVID-19) and 17 healthy controls (HCs) and monitored them for up to 4 weeks. We analyzed the bacterial and fungal taxonomic profiles and loads of 232 gut and respiratory samples and we measured the blood levels of Interleukin 6, IgG, and IgM in COVID-19 patients. Upon ICU admission, the bacterial composition and load in the gut and respiratory samples were altered in critically ill patients compared with HCs. During their ICU stay, the patients experienced increased bacterial and fungal loads, drastic decreased bacterial richness, and progressive changes in bacterial and fungal taxonomic profiles. In the gut samples, six bacterial taxa could discriminate ICU-COV(+) from ICU-COV(-) cases upon ICU admission and the bacterial taxa were associated according to age, PaO2/FiO2, and CRP levels. In the respiratory samples of the ICU-COV(+) patients, bacterial signatures including Pseudomonas and Streptococcus were found to be correlated with the length of ICU stay. Our findings demonstrated that the gut and respiratory microbiome dysbiosis and bacterial signatures associated with critical illness emerged as biomarkers of COVID-19 severity and could be a potential predictor of ICU length of stay. We propose using a high-throughput sequencing approach as an alternative to traditional isolation techniques to monitor ICU patient infection.

Identification of bacteria and fungi inhabiting fruiting bodies of Burgundy truffle (Tuber aestivum Vittad.).

Tuber species may be regarded as complex microhabitats hosting diverse microorganisms inside their fruiting bodies. Here, we investigated the structure of microbial communities inhabiting the gleba of wild growing (in stands) T. aestivum, using Illumina sequencing and culture-based methods. The two methods used in combination allowed to extract more information on complex microbiota of Tuber aestivum gleba. Analysis of the V3-V4 region of 16S rDNA identified nine phyla of bacteria present in the gleba of T. aestivum ascomata, mostly Proteobacteria from the family Bradyrhizobiaceae. Our results ideally match the earlier data for other Tuber species where the family Bradyrhizobiaceae was the most represented. The ITS1 region of fungal rDNA represented six alien fungal species belonging to three phyla. To complement the metagenomic analysis, cultivable fungi and bacteria were obtained from the gleba of the same T. aestivum fruiting bodies. The identified fungi mostly belong to the phylum Basidiomycota and same to Ascomycota. Analysis of cultivable bacteria revealed that all the specimens were colonized by different strains of Bacillus. Fungal community inhabiting T. aestivum fruiting bodies was never shown before.

Malassezia species dysbiosis in natural and allergen-induced atopic dermatitis in dogs.

Malassezia dermatitis and otitis are recurrent features of canine atopic dermatitis, increasing the cost of care, and contributing to a reduced quality of life for the pet. The exact pathogenesis of secondary yeast infections in allergic dogs remains unclear, but some have proposed an overgrowth of M. pachydermatis to be one of the flare factors. The distribution of Malassezia populations on healthy and allergic canine skin has not been previously investigated using culture-independent methods. Skin swabs were collected from healthy, naturally affected allergic, and experimentally sensitized atopic dogs. From the extracted DNA, fungal next-generations sequencing (NGS) targeting the ITS region with phylogenetic analysis of sequences for species level classification, and Malassezia species-specific quantitative real-time polymerase chain reaction (qPCR) were performed. M. globosa was significantly more abundant on healthy canine skin by both methods (NGS P < .0001, qPCR P < .0001). M. restricta was significantly more abundant on healthy skin by NGS (P = .0023), and M. pachydermatis was significantly more abundant on naturally-affected allergic skin by NGS (P < .0001) and on allergen-induced atopic skin lesions by qPCR (P = .0015). Shifts in Malassezia populations were not observed in correlation with the development of allergen-induced skin lesions. Differences in the lipid dependency of predominant Malassezia commensals between groups suggests a role of the skin lipid content in driving community composition and raises questions of whether targeting skin lipids with therapeutics could promote healthy Malassezia populations on canine skin.

Skin Mycobiome of Psoriasis Patients is Retained during Treatment with TNF and IL-17 Inhibitors.

BACKGROUND: Biological treatment relieves refractory skin lesions in patients with psoriasis; however, changes in the fungal microbiome (the mycobiome) on the skin are unclear. METHODS: The skin mycobiome of psoriasis patients treated with TNF inhibitors (TNFi, n = 5) and IL-17 inhibitors (IL-17i, n = 7) was compared with that of patients not receiving systemic therapy (n = 7). Skin swab samples were collected from non-lesional post-auricular areas. Fungal DNA was sequenced by ITS1 metagenomic analysis and taxonomic classification was performed. RESULTS: An average of 37543 reads/sample were analyzed and fungi belonging to 31 genera were detected. The genus Malassezia accounted for >90% of reads in 7/7 samples from the no-therapy group, 4/5 from the TNFi group, and 5/7 from the IL-17i group. Biodiversity was low in those three groups. Few members of the genus trichophyton were detected; the genus Candida was not detected at all. Among the Malassezia species, M. restricta was the major species in 6/7 samples from the no-therapy group, 4/5 from the TNFi group, and 5/7 from the IL-17i group whose the other largest species revealed M. globosa. CONCLUSIONS: The mycobiome is retained on post-auricular skin during systemic treatment with TNF and IL-17 inhibitors.

Plant-mediated effects of soil phosphorus on the root-associated fungal microbiota in Arabidopsis thaliana.

Plants respond to phosphorus (P) limitation through an array of morphological, physiological and metabolic changes which are part of the phosphate (Pi) starvation response (PSR). This response influences the establishment of the arbuscular mycorrhizal (AM) symbiosis in most land plants. It is, however, unknown to what extent available P and the PSR redefine plant interactions with the fungal microbiota in soil. Using amplicon sequencing of the fungal taxonomic marker ITS2, we examined the changes in root-associated fungal communities in the AM nonhost species Arabidopsis thaliana in response to soil amendment with P and to genetic perturbations in the plant PSR. We observed robust shifts in root-associated fungal communities of P-replete plants in comparison with their P-deprived counterparts, while bulk soil communities remained unaltered. Moreover, plants carrying mutations in the phosphate signaling network genes, phr1, phl1 and pho2, exhibited similarly altered root fungal communities characterized by the depletion of the chytridiomycete taxon Olpidium brassicae specifically under P-replete conditions. This study highlights the nutritional status and the underlying nutrient signaling network of an AM nonhost plant as previously unrecognized factors influencing the assembly of the plant fungal microbiota in response to P in nonsterile soil.

Analysis of the influence of living environment and age on vaginal fungal microbiome in giant pandas (Ailuropoda melanoleuca) by high throughput sequencing.

A recent study has described the normal vaginal bacterial community in giant pandas, but there is a lack of knowledge of the fungal community residing in the vagina of giant pandas. In order to comprehensively understand the vaginal fungal microbial diversity and abundance in giant pandas, high throughput sequencing was used to analyse the ITS1 region, based on thirteen samples taken from the pandas' vaginas, which were grouped by sampling points and age. The results showed that the most abundant phyla were Basidiomycota (73.37%), followed by Ascomycota (20.04%), Zygomycota (5.23%), Glomeromycota (0.014%) and Chytridiomycota (0.006%). At the genus level, Guehomyces (37.92%) was the most abundant, followed by Cladosporium (9.072%), Trichosporon (6.2%) and Mucor (4.97%). Furthermore, Candida only accounted for a low percentage of the vaginal fungal community. With the saturation of rarefaction curves and fungal diversity indices, the samples from Dujiangyan and Chungking Safari Park (DC group) showed a higher fungal species richness and diversity than other living environments. Shannon diversity indices showed significant difference between group WL (Wolong nature reserve) and DC (P < .05). Additionally, a higher diversity was found in ten to fifteen years old (Group 2) than other groups. Group 2 and Group 3 displayed significant differences in the diversities of their vaginal fungal communities (P < .05). These data that has been collected from this research will be helpful for further study to improve the reproductive status of giant pandas.

CONSTAX: a tool for improved taxonomic resolution of environmental fungal ITS sequences.

BACKGROUND: One of the most crucial steps in high-throughput sequence-based microbiome studies is the taxonomic assignment of sequences belonging to operational taxonomic units (OTUs). Without taxonomic classification, functional and biological information of microbial communities cannot be inferred or interpreted. The internal transcribed spacer (ITS) region of the ribosomal DNA is the conventional marker region for fungal community studies. While bioinformatics pipelines that cluster reads into OTUs have received much attention in the literature, less attention has been given to the taxonomic classification of these sequences, upon which biological inference is dependent. RESULTS: Here we compare how three common fungal OTU taxonomic assignment tools (RDP Classifier, UTAX, and SINTAX) handle ITS fungal sequence data. The classification power, defined as the proportion of assigned OTUs at a given taxonomic rank, varied among the classifiers. Classifiers were generally consistent (assignment of the same taxonomy to a given OTU) across datasets and ranks; a small number of OTUs were assigned unique classifications across programs. We developed CONSTAX (CONSensus TAXonomy), a Python tool that compares taxonomic classifications of the three programs and merges them into an improved consensus taxonomy. This tool also produces summary classification outputs that are useful for downstream analyses. CONCLUSIONS: Our results demonstrate that independent taxonomy assignment tools classify unique members of the fungal community, and greater classification power is realized by generating consensus taxonomy of available classifiers with CONSTAX.

Fungal Microbiome of Alive and Dead Korean Fir in its Native Habitats.

A rapid decline of Abies koreana has been reported in most of the natural alpine habitats in Korea. It is generally accepted that this phenomenon is due to climate change even though no clear conclusions have been drawn. Most research has focused on abiotic environmental factors, but studies on the relationships between A. koreana and soil fungal microbiomes are scarce. In this study, the rhizoplane and rhizosphere fungal communities in the alive and dead Korean fir trees from its three major natural habitats including Mt. Deogyu, Mt. Halla, and Mt. Jiri in Korea were investigated to identify specific soil fungal groups closely associated with A. koreana. Soil fungal diversity in each study site was significantly different from another based on the beta diversity calculations. Heat tree analysis at the genus level showed that Clavulina, Beauveria, and Tomentella were most abundant in the healthy trees probably by forming ectomycorrhizae with Korean fir growth and controlling pests and diseases. However, Calocera, Dacrymyces, Gyoerffyella, Hydnotrya, Microdochium, Hyaloscypha, Mycosymbioces, and Podospora were abundant in the dead trees. Our findings suggested that Clavulina, Beauveria, and Tomentella are the major players that could be considered in future reforestation programs to establish ectomycorrhizal networks and promote growth. These genera may have played a significant role in the survival and growth of A. koreana in its natural habitats. In particular, the genus Gyoerffyella may account for the death of the seedlings. Our work presented exploratory research on the specific fungal taxa associated with the status of A. koreana.

Differences in ingestion and biodegradation of the melamine formaldehyde plastic by yellow mealworms Tenebrio molitor and superworms Zophobas atratus, and the prediction of functional gut microbes.

Plastics biodegradation by insect larvae is considered as a new strategy for plastic wastes treatment. To uncover the biodegradation of a more complex chemical polymer of melamine formaldehyde (MF) by insect larvae, two worm species of yellow mealworm Tenebrio molitor and superworm Zophobas atratus were fed on MF foam as sole diet for 45 days with sole bran diet as control. Although the MF foam consumption by yellow mealworms of 0.38 mg/d/g-larvae was almost 40% higher than that by superworms of 0.28 mg/d/g-larvae, a similar decrease of survival rates in both species were obtained at about 58%, indicating the adverse effects on their growth. Depolymerization and biodegradation of MF foam occurred in both larval guts, but was more extensive in yellow mealworms. MF foam sole diet influenced gut bacterial and fungal microbiomes of both larvae species, which were assessed by Illumina MiSeq on day 45. Compared to the bran-fed group, both gut bacterial and fungal communities significantly changed in MF-fed groups, but differed in the two larvae species. The results demonstrated a strong association between the distinctive gut microbiome and MF foam degradation, such as unclassified Enterobacteriaceae, Hyphopichia and Issatchenkia. However, sole MF foam diet negatively influenced worms, like lower survival rates and gut abnormalities. In summary, MF foam could be degraded by both yellow mealworms and superworms, albeit with adverse effects. Gut microbes were strongly associated to MF foam degradation, especially the gut fungi.

Methods for identification of the opportunistic gut mycobiome from colorectal adenocarcinoma biopsy tissues.

Colorectal cancer poses a significant threat to global health, necessitating the development of effective early detection techniques. However, the potential of the fungal microbiome as a putative biomarker for the detection of colorectal adenocarcinoma has not been extensively explored. We analyzed the viability of implementing the fungal mycobiome for this purpose. Biopsies were collected from cancer and polyp patients. The total genomic DNA was extracted from the biopsy samples by utilizing a comprehensive kit to ensure optimal microbial DNA recovery. To characterize the composition and diversity of the fungal mycobiome, high-throughput amplicon sequencing targeting the internal transcribed spacer 1 (ITS1) region was proposed. A comparative analysis revealed discrete fungal profiles among the diseased groups. Here, we also proposed pipelines based on a predictive model using statistical and machine learning algorithms to accurately differentiate colorectal adenocarcinoma and polyp patients from normal individuals. These findings suggest the utility of gut mycobiome as biomarkers for the detection of colorectal adenocarcinoma. Expanding our understanding of the role of the gut mycobiome in disease detection creates novel opportunities for early intervention and personalized therapeutic strategies for colorectal cancer.•Detailed method to identify the gut mycobiome in colorectal cancer patients using ITS-specific amplicon sequencing.•Application of machine learning algorithms to the identification of potential mycobiome biomarkers for non-invasive colorectal cancer screening.•Contribution to the advancement of innovative colorectal cancer diagnostic methods and targeted therapies by applying gut mycobiome knowledge.

It's time to shed some light on the importance of fungi in neonatal intensive care units: what do we know about the neonatal mycobiome?

The 21st century, thanks to the development of molecular methods, including DNA barcoding, using Sanger sequencing, and DNA metabarcoding, based on next-generation sequencing (NGS), is characterized by flourishing research on the human microbiome. Microbial dysbiosis is perceived as a new pathogenetic factor for neonatal diseases. Fungi are crucial, but neglected, components of the neonatal microbiome, which, despite their low abundance, significantly impact morbidity and mortality rates of premature infants hospitalized in Neonatal Intensive Care Units (NICUs). The neonatal mycobiome's composition and effect on health remain poorly studied research areas. Our knowledge about neonatal mycobiome, composed of limited genera, is mainly based on research on the bacterial microbiome. We presume it is influenced by clinical factors, including prematurity, antibiotic therapy, and type of delivery. Understanding these risk factors may be useful in prevention strategies against dysbiosis and invasive fungal infections. Despite the methodological challenges resulting from the biology of the fungal cell, this topic is an attractive area of research that may contribute to more effective treatment, especially of newborns from risk groups. In this mini review, we discuss the current state of knowledge, research gaps, study difficulties, and future research directions on the neonatal mycobiome, concerning potential future clinical applications.

Characteristics and Correlations of the Oral and Gut Fungal Microbiome with Hypertension.

The mycobiome is an essential constituent of the human microbiome and is associated with various diseases. However, the role of oral and gut fungi in hypertension (HTN) remains largely unexplored. In this study, saliva, subgingival plaques, and feces were collected from 36 participants with HTN and 24 healthy controls for metagenomic sequencing. The obtained sequences were analyzed using the Kraken2 taxonomic annotation pipeline to assess fungal composition and diversity. Correlations between oral and gut fungi and clinic parameters, between fungi within the same sample types, and between different sample types were identified by Spearman's correlation analysis. Overall, the subgingival fungal microbiome had substantially higher alpha diversity than the salivary and fecal fungal microbiomes. The fungal microbiomes of the three sample types displayed distinct beta diversity from each other. Oral fungi but not gut fungi in HTN had beta diversity significantly different from that of controls. Among the fungi shared in the oral cavity and gut, Exophiala was the genus with the most notable changes. Exophiala spinifera was the most abundant salivary species in HTN. Some fungal species directly correlated with blood pressure, including gut Exophiala xenobiotica and Exophiala mesophila. The markedly impaired ecological cocorrelation networks of oral and gut fungi in HTN suggested compromised association among fungal species. Most fungi were shared in the oral cavity and gut, and their correlations suggested the potential interplays between oral and gut fungi. In conclusion, the oral cavity and intestine have unique fungal ecological environments. The fungal enrichment and ecology in HTN, the correlations between oral and gut fungi, and the associations between oral and gut fungi and clinical parameters suggest an important role that the fungal microbiome may play in HTN. IMPORTANCE Our study fills the gap in human studies investigating the oral and gut fungal microbiota in association with blood pressure. It characterizes the diversity and composition of the oral and gut fungal microbiome in human subjects, elucidates the dysbiosis of fungal ecology in a hypertensive population, and establishes oral-gut fungal correlations and fungus-clinical parameter correlations. Targeting fungi in the oral cavity and/or gut may provide novel strategies for the prevention and treatment of hypertension.

A Rare Case of Demodicosis Following Treatment With Oral Fluconazole.

Demodex folliculorum and Demodex brevis are commensal human ectoparasites that reside within or near hair follicles and have been highly associated with rosacea-like papulopustular skin eruptions. We present an interesting case of recurrent, iatrogenic demodicosis in a 56-year-old man. We suspect this to have been triggered by antifungal therapy given it occurred twice closely following azole treatment. We propose that oral antifungals in the setting of immunosuppression can alter the skin microbiome, facilitating Demodex proliferation.

The Influence of Oral Terbinafine on Gut Fungal Microbiome Composition and Microbial Translocation in People Living with HIV Treated for Onychomycosis.

People living with HIV (PLWH) display altered gut epithelium that allows for the translocation of microbial products, contributing to systemic immune activation. Although there are numerous studies which examine the gut bacterial microbiome in PLWH, few studies describing the fungal microbiome, or the mycobiome, have been reported. Like the gut bacterial microbiome, the fungal microbiome and its by-products play a role in maintaining the body's homeostasis and modulating immune function. We conducted a prospective study to assess the effects of oral terbinafine, an antifungal agent widely used against onychomycosis, on gut permeability and microbiome composition in ART-treated PLWH (trial registration: ChiCTR2100043617). Twenty participants completed all follow-up visits. During terbinafine treatment, the levels of the intestinal fatty acid binding protein (I-FABP) significantly increased, and the levels of interleukin-6 (IL-6) significantly decreased, from baseline to week 12. Both markers subsequently returned to pre-treatment levels after terbinafine discontinuation. After terbinafine treatment, the abundance of fungi decreased significantly, while the abundance of the bacteria did not change. After terbinafine discontinuation, the abundance of fungi returned to the levels observed pre-treatment. Moreover, terbinafine treatment induced only minor changes in the composition of the gut bacterial and fungal microbiome. In summary, oral terbinafine decreases fungal microbiome abundance while only slightly influencing gut permeability and microbial translocation in ART-treated PLWH. This study's findings should be validated in larger and more diverse studies of ART-treated PLWH; our estimates of effect size can be used to inform optimal sample sizes for future studies.

Compositional Shifts and Assembly in Rhizosphere-Associated Fungal Microbiota Throughout the Life Cycle of Japonica Rice Under Increased Nitrogen Fertilization.

Soil fungal microbiomes facilitate a range of beneficial functions for their host plants, and rhizosphere fungal community composition, richness, and diversity affect plant growth and development, and crop yield. Therefore, exploring the community structure and assembly of the rhizosphere fungal microbiome and its relationship with soil biochemical properties are fundamental to elucidating how rice plants benefit from their fungal symbionts. In this study, soil samples were collected at seedling, tillering, heading, and ripening stages of rice subjected to three levels of nitrogen fertilization. Plant growth demonstrates a substantial influence on fungal community composition and diversity. From the tillering to the ripening stage, the fungal communities were governed by homogenizing dispersal and dispersal limitation. The prevalence of Glomeromycota, the beneficial fungi, was considerably higher during the heading stage compared to the three other growth stages. This increase in abundance was strongly associated with increased levels of soil nutrients and enhanced activity of nitrogen acquisition enzymes. This may be a strategy developed by rice grown in flooded soil to recruit beneficial fungi in the rhizosphere to meet high nitrogen demands. Our study findings contribute to elucidating the influence of plant development and nitrogen fertilization on the structure and composition of the fungal community as well as its relationship with soil key soil nutrient content and nitrogen-related enzyme activities. They also illustrate how a shift in the fungal community mediates and reflects the effects of nitrogen fertilization input in rice agroecosystems. These findings provide new insights into the effects of changes in nitrogen application in rice rhizosphere at different growth stages on fungal communities and soil biochemical characteristics.

The fungus Clonostachys epichloë alters the influence of the Epichloë endophyte on seed germination and the biomass of Puccinellia distans grass.

The fungal grass endophyte Epichloë typhina (Pers.) Tul. & C. Tul. (Ascomycota: Clavicipitaceae) grows intercellulary in aerial plant parts and reproduces asexually by invading host seeds. In this phase, it enhances seed production and germination, which accelerates its vertical spread. This relationship may be distorted by other seed-born fungi, whose spread is not so directly dependent on the success of the grass. Recently, the fungus Clonostachys epichloë Schroers has been observed on Puccinellia distans (Jacq.) Parl seeds originating from grass clumps infested with stromata, sexual structures of Epichloë typhina that are formed in spring on some host culms, preventing flower and seed development ('choke disease'). C. epichloë shows mycoparasitic activity toward Epichloë stromata by reducing the production of ascospores, which are responsible for horizontal transmission of the fungus. The aim of this study was to investigate the effect of seed-borne C. epichloë on seed germination, as well as the size and weight of P. distans seedlings and to examine whether C. epichloë alters the influence of Epichloë in the early developmental stages of P. distans. The results showed that if C. epichloë acts on seeds together with E. typhina endophytes, the seeds were negatively affected due to the elimination of the positive effect of the latter in terms of both seed germination rate and seedling length. At the same time, C. epichloë increased the proportion of E. typhina-untreated germinated seeds. Additionally, only the joint action of the two fungi, E. typhina and C. epichloë, effectively stimulated seedling dry mass; the presence of E. typhina alone was not sufficient to noticeably affect seedling size. Based on the increasing commonality of C. epichloë on Epichloë stromata, as well as its potential to be used in biocontrol of 'choke disease', we should take a closer look at this fungus, not only in terms of its mycoparasitic ability, but also in terms of its cumulative impact on the whole Epichloë-grass system.

Diversity of fungal microbiome obtained from plant rhizoplanes.

Microbial communities, and their ecological importance, have been investigated in several habitats. However, so far, most studies could not describe the closest microbial interactions and their functionalities. This study investigates the co-occurring interactions between fungi and bacteria in plant rhizoplanes and their potential functions. The partnerships were obtained using fungal-highway columns with four plant-based media. The fungi and associated microbiomes isolated from the columns were identified by sequencing the ITS (fungi) and 16S rRNA genes (bacteria). Statistical analyses including Exploratory Graph and Network Analysis were used to visualize the presence of underlying clusters in the microbial communities and evaluate the metabolic functions associated with the fungal microbiome (PICRUSt2). Our findings characterize the presence of both unique and complex bacterial communities associated with different fungi. The results showed that Bacillus was associated as exo-bacteria in 80 % of the fungi but occurred as putative endo-bacteria in 15 %. A shared core of putative endo-bacterial genera, potentially involved in the nitrogen cycle was found in 80 % of the isolated fungi. The comparison of potential metabolic functions of the putative endo- and exo-communities highlighted the potential essential factors to establish an endosymbiotic relationship, such as the loss of pathways associated with metabolites obtained from the host while maintaining pathways responsible for bacterial survival within the hypha.