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1.
Cell ; 187(12): 2969-2989.e24, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38776919

RESUMO

The gut fungal community represents an essential element of human health, yet its functional and metabolic potential remains insufficiently elucidated, largely due to the limited availability of reference genomes. To address this gap, we presented the cultivated gut fungi (CGF) catalog, encompassing 760 fungal genomes derived from the feces of healthy individuals. This catalog comprises 206 species spanning 48 families, including 69 species previously unidentified. We explored the functional and metabolic attributes of the CGF species and utilized this catalog to construct a phylogenetic representation of the gut mycobiome by analyzing over 11,000 fecal metagenomes from Chinese and non-Chinese populations. Moreover, we identified significant common disease-related variations in gut mycobiome composition and corroborated the associations between fungal signatures and inflammatory bowel disease (IBD) through animal experimentation. These resources and findings substantially enrich our understanding of the biological diversity and disease relevance of the human gut mycobiome.


Assuntos
Fungos , Microbioma Gastrointestinal , Micobioma , Animais , Humanos , Masculino , Camundongos , Fezes/microbiologia , Fungos/genética , Fungos/classificação , Fungos/isolamento & purificação , Genoma Fúngico/genética , Genômica , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/genética , Metagenoma , Filogenia , Feminino , Adulto , Pessoa de Meia-Idade
2.
N Engl J Med ; 389(23): 2140-2150, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38055252

RESUMO

BACKGROUND: Janus kinase (JAK) inhibitors, including baricitinib, block cytokine signaling and are effective disease-modifying treatments for several autoimmune diseases. Whether baricitinib preserves ß-cell function in type 1 diabetes is unclear. METHODS: In this phase 2, double-blind, randomized, placebo-controlled trial, we assigned patients with type 1 diabetes diagnosed during the previous 100 days to receive baricitinib (4 mg once per day) or matched placebo orally for 48 weeks. The primary outcome was the mean C-peptide level, determined from the area under the concentration-time curve, during a 2-hour mixed-meal tolerance test at week 48. Secondary outcomes included the change from baseline in the glycated hemoglobin level, the daily insulin dose, and measures of glycemic control assessed with the use of continuous glucose monitoring. RESULTS: A total of 91 patients received baricitinib (60 patients) or placebo (31 patients). The median of the mixed-meal-stimulated mean C-peptide level at week 48 was 0.65 nmol per liter per minute (interquartile range, 0.31 to 0.82) in the baricitinib group and 0.43 nmol per liter per minute (interquartile range, 0.13 to 0.63) in the placebo group (P = 0.001). The mean daily insulin dose at 48 weeks was 0.41 U per kilogram of body weight per day (95% confidence interval [CI], 0.35 to 0.48) in the baricitinib group and 0.52 U per kilogram per day (95% CI, 0.44 to 0.60) in the placebo group. The levels of glycated hemoglobin were similar in the two trial groups. However, the mean coefficient of variation of the glucose level at 48 weeks, as measured by continuous glucose monitoring, was 29.6% (95% CI, 27.8 to 31.3) in the baricitinib group and 33.8% (95% CI, 31.5 to 36.2) in the placebo group. The frequency and severity of adverse events were similar in the two trial groups, and no serious adverse events were attributed to baricitinib or placebo. CONCLUSIONS: In patients with type 1 diabetes of recent onset, daily treatment with baricitinib over 48 weeks appeared to preserve ß-cell function as estimated by the mixed-meal-stimulated mean C-peptide level. (Funded by JDRF International and others; BANDIT Australian New Zealand Clinical Trials Registry number, ACTRN12620000239965.).


Assuntos
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Inibidores de Janus Quinases , Humanos , Austrália , Glicemia/análise , Automonitorização da Glicemia , Peptídeo C/sangue , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hemoglobinas Glicadas/análise , Insulina/uso terapêutico , Inibidores de Janus Quinases/efeitos adversos , Inibidores de Janus Quinases/farmacologia , Inibidores de Janus Quinases/uso terapêutico , Células Secretoras de Insulina/efeitos dos fármacos , Método Duplo-Cego
3.
Proc Natl Acad Sci U S A ; 119(20): e2201113119, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35533275

RESUMO

The deadly toxin α-amanitin is a bicyclic octapeptide biosynthesized on ribosomes. A phylogenetically disjunct group of mushrooms in Agaricales (Amanita, Lepiota, and Galerina) synthesizes α-amanitin. This distribution of the toxin biosynthetic pathway is possibly related to the horizontal transfer of metabolic gene clusters among taxonomically unrelated mushrooms with overlapping habitats. Here, our work confirms that two biosynthetic genes, P450-29 and FMO1, are oxygenases important for amanitin biosynthesis. Phylogenetic and genetic analyses of these genes strongly support their origin through horizontal transfer, as is the case for the previously characterized biosynthetic genes MSDIN and POPB. Our analysis of multiple genomes showed that the evolution of the α-amanitin biosynthetic pathways in the poisonous agarics in the Amanita, Lepiota, and Galerina clades entailed distinct evolutionary pathways including gene family expansion, biosynthetic genes, and genomic rearrangements. Unrelated poisonous fungi produce the same deadly amanitin toxins using variations of the same pathway. Furthermore, the evolution of the amanitin biosynthetic pathway(s) in Amanita species generates a much wider range of toxic cyclic peptides. The results reported here expand our understanding of the genetics, diversity, and evolution of the toxin biosynthetic pathway in fungi.


Assuntos
Amanitinas , Toxinas Biológicas , Amanita/genética , Amanitinas/genética , Evolução Biológica , Vias Biossintéticas/genética , Transferência Genética Horizontal
4.
Proc Natl Acad Sci U S A ; 119(3)2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35012977

RESUMO

Small RNAs (sRNAs) are known to regulate pathogenic plant-microbe interactions. Emerging evidence from the study of these model systems suggests that microRNAs (miRNAs) can be translocated between microbes and plants to facilitate symbiosis. The roles of sRNAs in mutualistic mycorrhizal fungal interactions, however, are largely unknown. In this study, we characterized miRNAs encoded by the ectomycorrhizal fungus Pisolithus microcarpus and investigated their expression during mutualistic interaction with Eucalyptus grandis. Using sRNA sequencing data and in situ miRNA detection, a novel fungal miRNA, Pmic_miR-8, was found to be transported into E. grandis roots after interaction with P. microcarpus Further characterization experiments demonstrate that inhibition of Pmic_miR-8 negatively impacts the maintenance of mycorrhizal roots in E. grandis, while supplementation of Pmic_miR-8 led to deeper integration of the fungus into plant tissues. Target prediction and experimental testing suggest that Pmic_miR-8 may target the host NB-ARC domain containing transcripts, suggesting a potential role for this miRNA in subverting host signaling to stabilize the symbiotic interaction. Altogether, we provide evidence of previously undescribed cross-kingdom sRNA transfer from ectomycorrhizal fungi to plant roots, shedding light onto the involvement of miRNAs during the developmental process of mutualistic symbioses.


Assuntos
Basidiomycota/genética , Inativação Gênica , MicroRNAs/metabolismo , Micorrizas/genética , Simbiose/genética , Sequência de Bases , Basidiomycota/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , MicroRNAs/genética , Raízes de Plantas/microbiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
5.
Mol Biol Evol ; 40(3)2023 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-36811946

RESUMO

The mutualistic ectomycorrhizal (ECM) fungal genus Pisolithus comprises 19 species defined to date which colonize the roots of >50 hosts worldwide suggesting that substantial genomic and functional evolution occurred during speciation. To better understand this intra-genus variation, we undertook a comparative multi-omic study of nine Pisolithus species sampled from North America, South America, Asia, and Australasia. We found that there was a small core set of genes common to all species (13%), and that these genes were more likely to be significantly regulated during symbiosis with a host than accessory or species-specific genes. Thus, the genetic "toolbox" foundational to the symbiotic lifestyle in this genus is small. Transposable elements were located significantly closer to gene classes including effector-like small secreted proteins (SSPs). Poorly conserved SSPs were more likely to be induced by symbiosis, suggesting that they may be a class of protein that tune host specificity. The Pisolithus gene repertoire is characterized by divergent CAZyme profiles when compared with other fungi, both symbiotic and saprotrophic. This was driven by differences in enzymes associated with symbiotic sugar processing, although metabolomic analysis suggest that neither copy number nor expression of these genes is sufficient to predict sugar capture from a host plant or its metabolism in fungal hyphae. Our results demonstrate that intra-genus genomic and functional diversity within ECM fungi is greater than previously thought, underlining the importance of continued comparative studies within the fungal tree of life to refine our focus on pathways and evolutionary processes foundational to this symbiotic lifestyle.


Assuntos
Basidiomycota , Micorrizas , Micorrizas/genética , Simbiose/genética , Basidiomycota/genética , Raízes de Plantas , Açúcares
6.
New Phytol ; 242(4): 1486-1506, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38297461

RESUMO

Mycorrhizal symbioses between plants and fungi are vital for the soil structure, nutrient cycling, plant diversity, and ecosystem sustainability. More than 250 000 plant species are associated with mycorrhizal fungi. Recent advances in genomics and related approaches have revolutionized our understanding of the biology and ecology of mycorrhizal associations. The genomes of 250+ mycorrhizal fungi have been released and hundreds of genes that play pivotal roles in regulating symbiosis development and metabolism have been characterized. rDNA metabarcoding and metatranscriptomics provide novel insights into the ecological cues driving mycorrhizal communities and functions expressed by these associations, linking genes to ecological traits such as nutrient acquisition and soil organic matter decomposition. Here, we review genomic studies that have revealed genes involved in nutrient uptake and symbiosis development, and discuss adaptations that are fundamental to the evolution of mycorrhizal lifestyles. We also evaluated the ecosystem services provided by mycorrhizal networks and discuss how mycorrhizal symbioses hold promise for sustainable agriculture and forestry by enhancing nutrient acquisition and stress tolerance. Overall, unraveling the intricate dynamics of mycorrhizal symbioses is paramount for promoting ecological sustainability and addressing current pressing environmental concerns. This review ends with major frontiers for further research.


Assuntos
Agricultura , Ecologia , Genômica , Micorrizas , Simbiose , Micorrizas/fisiologia , Micorrizas/genética , Simbiose/genética , Pesquisa , Plantas/microbiologia
7.
New Phytol ; 243(1): 381-397, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38741469

RESUMO

Ectomycorrhizal symbiosis, which involves mutually beneficial interactions between soil fungi and tree roots, is essential for promoting tree growth. To establish this symbiotic relationship, fungal symbionts must initiate and sustain mutualistic interactions with host plants while avoiding host defense responses. This study investigated the role of reactive oxygen species (ROS) generated by fungal NADPH oxidase (Nox) in the development of Laccaria bicolor/Populus tremula × alba symbiosis. Our findings revealed that L. bicolor LbNox expression was significantly higher in ectomycorrhizal roots than in free-living mycelia. RNAi was used to silence LbNox, which resulted in decreased ROS signaling, limited formation of the Hartig net, and a lower mycorrhizal formation rate. Using Y2H library screening, BiFC and Co-IP, we demonstrated an interaction between the mitogen-activated protein kinase LbSakA and LbNoxR. LbSakA-mediated phosphorylation of LbNoxR at T409, T477 and T480 positively modulates LbNox activity, ROS accumulation and upregulation of symbiosis-related genes involved in dampening host defense reactions. These results demonstrate that regulation of fungal ROS metabolism is critical for maintaining the mutualistic interaction between L. bicolor and P. tremula × alba. Our findings also highlight a novel and complex regulatory mechanism governing the development of symbiosis, involving both transcriptional and posttranslational regulation of gene networks.


Assuntos
Proteínas Fúngicas , Laccaria , Micorrizas , NADPH Oxidases , Espécies Reativas de Oxigênio , Simbiose , Laccaria/fisiologia , Laccaria/genética , Laccaria/metabolismo , Micorrizas/fisiologia , NADPH Oxidases/metabolismo , NADPH Oxidases/genética , Espécies Reativas de Oxigênio/metabolismo , Fosforilação , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética
8.
New Phytol ; 242(2): 658-674, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38375883

RESUMO

The jasmonic acid (JA) signalling pathway plays an important role in the establishment of the ectomycorrhizal symbiosis. The Laccaria bicolor effector MiSSP7 stabilizes JA corepressor JAZ6, thereby inhibiting the activity of Populus MYC2 transcription factors. Although the role of MYC2 in orchestrating plant defences against pathogens is well established, its exact contribution to ECM symbiosis remains unclear. This information is crucial for understanding the balance between plant immunity and symbiotic relationships. Transgenic poplars overexpressing or silencing for the two paralogues of MYC2 transcription factor (MYC2s) were produced, and their ability to establish ectomycorrhiza was assessed. Transcriptomics and DNA affinity purification sequencing were performed. MYC2s overexpression led to a decrease in fungal colonization, whereas its silencing increased it. The enrichment of terpene synthase genes in the MYC2-regulated gene set suggests a complex interplay between the host monoterpenes and fungal growth. Several root monoterpenes have been identified as inhibitors of fungal growth and ECM symbiosis. Our results highlight the significance of poplar MYC2s and terpenes in mutualistic symbiosis by controlling root fungal colonization. We identified poplar genes which direct or indirect control by MYC2 is required for ECM establishment. These findings deepen our understanding of the molecular mechanisms underlying ECM symbiosis.


Assuntos
Ciclopentanos , Laccaria , Micorrizas , Oxilipinas , Populus , Micorrizas/genética , Populus/metabolismo , Raízes de Plantas/metabolismo , Simbiose/genética , Laccaria/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Monoterpenos/metabolismo
9.
New Phytol ; 242(4): 1676-1690, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38148573

RESUMO

Soil fungi belonging to different functional guilds, such as saprotrophs, pathogens, and mycorrhizal symbionts, play key roles in forest ecosystems. To date, no study has compared the actual gene expression of these guilds in different forest soils. We used metatranscriptomics to study the competition for organic resources by these fungal groups in boreal, temperate, and Mediterranean forest soils. Using a dedicated mRNA annotation pipeline combined with the JGI MycoCosm database, we compared the transcripts of these three fungal guilds, targeting enzymes involved in C- and N mobilization from plant and microbial cell walls. Genes encoding enzymes involved in the degradation of plant cell walls were expressed at a higher level in saprotrophic fungi than in ectomycorrhizal and pathogenic fungi. However, ectomycorrhizal and saprotrophic fungi showed similarly high expression levels of genes encoding enzymes involved in fungal cell wall degradation. Transcripts for N-related transporters were more highly expressed in ectomycorrhizal fungi than in other groups. We showed that ectomycorrhizal and saprotrophic fungi compete for N in soil organic matter, suggesting that their interactions could decelerate C cycling. Metatranscriptomics provides a unique tool to test controversial ecological hypotheses and to better understand the underlying ecological processes involved in soil functioning and carbon stabilization.


Assuntos
Florestas , Fungos , Microbiologia do Solo , Transcriptoma , Fungos/genética , Fungos/fisiologia , Transcriptoma/genética , Micorrizas/fisiologia , Micorrizas/genética , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Nitrogênio/metabolismo , Solo/química , Ecossistema , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
10.
Mol Phylogenet Evol ; 193: 108010, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38195011

RESUMO

Nidulariaceae, also known as bird's nest fungi, is an understudied group of mushroom-forming fungi. The common name is derived from their nest-like morphology. Bird's nest fungi are ubiquitous wood decomposers or saprobes on dung. Recent studies showed that species in the Nidulariaceae form a monophyletic group with five sub-clades. However, phylogenetic relationships among genera and placement of Nidulariaceae are still unclear. We present phylogenomic analyses of bird's nest fungi and related Agaricales fungi to gain insight into the evolution of Nidulariaceae. A species tree with 17 newly generated genomes of bird's nest fungi and representatives from all major clades of Agaricales was constructed using 1044 single-copy genes to explore the intergeneric relationships and pinpoint the placement of Nidulariaceae within Agaricales. We corroborated the hypothesis that bird's nest fungi are sister to Squamanitaceae, which includes mushroom-shaped fungi with a stipe and pileus that are saprobes and mycoparasites. Lastly, stochastic character mapping of discrete traits on phylogenies (SIMMAP) suggests that the ancestor of bird's nest fungi likely possessed an evanescent, globose peridium without strings attaching to the spore packets (funiculi). This analysis suggests that the funiculus was gained twice and that the persistent, cupulate peridium form was gained at least four times and lost once. However, alternative coding schemes and datasets with a wider array of Agaricales produced conflicting results during ancestral state reconstruction, indicating that there is some uncertainty in the number of peridium transitions and that taxon sampling may significantly alter ancestral state reconstructions. Overall, our results suggest that several key morphological characters of Nidulariaceae have been subject to homoplasy.


Assuntos
Cyathus , Animais , Filogenia , Aves
11.
Analyst ; 149(12): 3380-3395, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38712606

RESUMO

Plant hormones are important in the control of physiological and developmental processes including seed germination, senescence, flowering, stomatal aperture, and ultimately the overall growth and yield of plants. Many currently available methods to quantify such growth regulators quickly and accurately require extensive sample purification using complex analytic techniques. Herein we used ultra-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) to create and validate the prediction of hormone concentrations made using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectral profiles of both freeze-dried ground leaf tissue and extracted xylem sap of Japanese knotweed (Reynoutria japonica) plants grown under different environmental conditions. In addition to these predictions made with partial least squares regression, further analysis of spectral data was performed using chemometric techniques, including principal component analysis, linear discriminant analysis, and support vector machines (SVM). Plants grown in different environments had sufficiently different biochemical profiles, including plant hormonal compounds, to allow successful differentiation by ATR-FTIR spectroscopy coupled with SVM. ATR-FTIR spectral biomarkers highlighted a range of biomolecules responsible for the differing spectral signatures between growth environments, such as triacylglycerol, proteins and amino acids, tannins, pectin, polysaccharides such as starch and cellulose, DNA and RNA. Using partial least squares regression, we show the potential for accurate prediction of plant hormone concentrations from ATR-FTIR spectral profiles, calibrated with hormonal data quantified by UHPLC-HRMS. The application of ATR-FTIR spectroscopy and chemometrics offers accurate prediction of hormone concentrations in plant samples, with advantages over existing approaches.


Assuntos
Reguladores de Crescimento de Plantas , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Reguladores de Crescimento de Plantas/análise , Análise dos Mínimos Quadrados , Folhas de Planta/química , Cromatografia Líquida de Alta Pressão/métodos , Máquina de Vetores de Suporte , Espectrometria de Massas/métodos , Análise de Componente Principal
12.
Analyst ; 149(2): 497-506, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38063458

RESUMO

Diabetes mellitus (DM) is a metabolic disease with an increasing prevalence that is causing worldwide concern. The pre-diabetes stage is the only reversible stage in the patho-physiological process towards DM. Due to the limitations of traditional methods, the diagnosis and detection of DM and pre-diabetes are complicated, expensive, and time-consuming. Therefore, it would be of great benefit to develop a simple, rapid and inexpensive diagnostic test. Herein, the infrared (IR) spectra of serum samples from 111 DM patients, 111 pre-diabetes patients and 333 healthy volunteers were collected using attenuated total reflection Fourier-transform IR (ATR-FTIR) spectroscopy and this was combined with the multivariate analysis of principal component analysis linear discriminant analysis (PCA-LDA) to develop a discriminant model to verify the diagnostic potential of this approach. The study found that the accuracy of the test model established by ATR-FTIR spectroscopy combined with PCA-LDA was 97%, and the sensitivity and specificity were 100% and 100% in the control group, 94% and 98% in the pre-diabetes group, and 91% and 98% in the DM group, respectively. This indicates that this method can effectively diagnose DM and pre-diabetes, which has far-reaching clinical significance.


Assuntos
Diabetes Mellitus , Estado Pré-Diabético , Humanos , Estado Pré-Diabético/diagnóstico , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Multivariada , Análise Discriminante , Diabetes Mellitus/diagnóstico , Análise de Componente Principal , Proteínas Mutadas de Ataxia Telangiectasia
13.
Ecotoxicol Environ Saf ; 278: 116390, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38705037

RESUMO

Microplastics (MPs) and benzo[a]pyrene (B[a]P) are prevalent environmental pollutants. Numerous studies have extensively reported their individual adverse effects on organisms. However, the combined effects and mechanisms of exposure in mammals remain unknown. Thus, this study aims to investigate the potential effects of oral administration of 0.5µm polystyrene (PS) MPs (1 mg/mL or 5 mg/mL), B[a]P (1 mg/mL or 5 mg/mL) and combined (1 mg/mL or 5 mg/mL) on 64 male SD rats by gavage method over 6-weeks. The results demonstrate that the liver histopathological examination showed that the liver lobules in the combined (5 mg/kg) group had blurred and loose boundaries, liver cord morphological disorders, and significant steatosis. The levels of AST, ALT, TC, and TG in the combined dose groups were significantly higher than those in the other groups, the combined (5 mg/kg) group had the lowest levels of antioxidant enzymes and the highest levels of oxidants. The expression of Nrf2 was lowest and the expression of P38, NF-κB, and TNF-α was highest in the combined (5 mg/kg) group. In conclusion, these findings indicate that the combination of PSMPs and B[a]P can cause the highest levels of oxidative stress and elicit markedly enhanced toxic effects, which cause severe liver damage.


Assuntos
Benzo(a)pireno , Fígado , Microplásticos , Estresse Oxidativo , Poliestirenos , Ratos Sprague-Dawley , Animais , Estresse Oxidativo/efeitos dos fármacos , Benzo(a)pireno/toxicidade , Microplásticos/toxicidade , Masculino , Poliestirenos/toxicidade , Fígado/efeitos dos fármacos , Fígado/patologia , Ratos , Poluentes Ambientais/toxicidade , Antioxidantes/metabolismo , NF-kappa B/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo
14.
Ecotoxicol Environ Saf ; 270: 115808, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38198896

RESUMO

Despite various plans to rationalize antibiotic use, antibiotic resistance in environmental bacteria is increasing due to the accumulation of antibiotic residues in the environment. This study aimed to test the ability of basidiomycete fungal strains to biotransform the antibiotic levofloxacin, a widely-used third-generation broad-spectrum fluoroquinolone, and to propose enzyme targets potentially involved in this biotransformation. The biotransformation process was performed using fungal strains. Levofloxacin biotransformation reached 100% after 9 days of culture with Porostereum spadiceum BS34. Using genomics and proteomics analyses coupled with activity tests, we showed that P. spadiceum produces several heme-peroxidases together with H2O2-producing enzymes that could be involved in the antibiotic biotransformation process. Using UV and high-resolution mass spectrometry, we were able to detect five levofloxacin degradation products. Their putative identity based on their MS2 fragmentation patterns led to the conclusion that the piperazine moiety was the main target of oxidative modification of levofloxacin by P. spadiceum, leading to a decrease in antibiotic activity.


Assuntos
Peróxido de Hidrogênio , Levofloxacino , Polyporales , Antibacterianos/química , Fluoroquinolonas/química , Fungos/metabolismo
15.
Mycorrhiza ; 34(1-2): 69-84, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38441669

RESUMO

Trees form symbioses with ectomycorrhizal (ECM) fungi, maintained in part through mutual benefit to both organisms. Our understanding of the signaling events leading to the successful interaction between the two partners requires further study. This is especially true for understanding the role of volatile signals produced by ECM fungi. Terpenoids are a predominant class of volatiles produced by ECM fungi. While several ECM genomes are enriched in the enzymes responsible for the production of these volatiles (i.e., terpene synthases (TPSs)) when compared to other fungi, we have limited understanding of the biochemical products associated with each enzyme and the physiological impact of specific terpenes on plant growth. Using a combination of phylogenetic analyses, RNA sequencing, and functional characterization of five TPSs from two distantly related ECM fungi (Laccaria bicolor and Pisolithus microcarpus), we investigated the role of these secondary metabolites during the establishment of symbiosis. We found that despite phylogenetic divergence, these TPSs produced very similar terpene profiles. We focused on the role of P. microcarpus terpenes and found that the fungus expressed a diverse array of mono-, di-, and sesquiterpenes prior to contact with the host. However, these metabolites were repressed following physical contact with the host Eucalyptus grandis. Exposure of E. grandis to heterologously produced terpenes (enriched primarily in γ -cadinene) led to a reduction in the root growth rate and an increase in P. microcarpus-colonized root tips. These results support a very early putative role of fungal-produced terpenes in the establishment of symbiosis between mycorrhizal fungi and their hosts.


Assuntos
Basidiomycota , Micorrizas , Sesquiterpenos , Micorrizas/fisiologia , Raízes de Plantas/metabolismo , Filogenia , Simbiose/fisiologia , Sesquiterpenos/metabolismo
16.
New Phytol ; 238(4): 1636-1650, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36856329

RESUMO

Root microbiota composition shifts during the development of most annual plants. Although some perennial plants can live for centuries, the host-microbiome partnerships and interaction mechanisms underlying their longevity remain unclear. To address this gap, we investigated age-related changes in the root metabolites, transcriptomes, and microbiome compositions of 1- to 35-yr-old Populus tomentosa trees. Ten co-response clusters were obtained according to their accumulation patterns, and members of each cluster displayed a uniform and clear pattern of abundance. Multi-omics network analysis demonstrated that the increased abundance of Actinobacteria with tree age was strongly associated with the flavonoid biosynthesis. Using genetic approaches, we demonstrate that the flavonoid biosynthesis regulator gene Transparent Testa 8 is associated with the recruitment of flavonoid-associated Actinobacteria. Further inoculation experiments of Actinobacteria isolates indicated that their colonization could significantly improve the host's phenotype. Site-directed mutagenesis revealed that the hyBl gene cluster, involved in biosynthesis of an aminocyclitol hygromycin B analog in Streptomyces isolate bj1, is associated with disease suppression. We hypothesize that interactions between perennial plants and soil microorganisms lead to gradual enrichment of a subset of microorganisms that may harbor a wealth of currently unknown functional traits.


Assuntos
Microbiota , Populus , Árvores/microbiologia , Raízes de Plantas/microbiologia , Microbiota/genética , Bactérias/metabolismo , Mecanismos de Defesa
17.
New Phytol ; 238(2): 845-858, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36702619

RESUMO

Ectomycorrhizal (EcM) fungi play a crucial role in the mineral nitrogen (N) nutrition of their host trees. While it has been proposed that several EcM species also mobilize organic N, studies reporting the EcM ability to degrade N-containing polymers, such as chitin, remain scarce. Here, we assessed the capacity of a representative collection of 16 EcM species to acquire 15 N from 15 N-chitin. In addition, we combined genomics and transcriptomics to identify pathways involved in exogenous chitin degradation between these fungal strains. Boletus edulis, Imleria badia, Suillus luteus, and Hebeloma cylindrosporum efficiently mobilized N from exogenous chitin. EcM genomes primarily contained genes encoding for the direct hydrolysis of chitin. Further, we found a significant relationship between the capacity of EcM fungi to assimilate organic N from chitin and their genomic and transcriptomic potentials for chitin degradation. These findings demonstrate that certain EcM fungal species depolymerize chitin using hydrolytic mechanisms and that endochitinases, but not exochitinases, represent the enzymatic bottleneck of chitin degradation. Finally, this study shows that the degradation of exogenous chitin by EcM fungi might be a key functional trait of nutrient cycling in forests dominated by EcM fungi.


Assuntos
Micorrizas , Micorrizas/genética , Micorrizas/metabolismo , Quitina/metabolismo , Árvores/metabolismo , Florestas , Genômica , Solo
18.
New Phytol ; 238(6): 2561-2577, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36807327

RESUMO

Ectomycorrhizas are an intrinsic component of tree nutrition and responses to environmental variations. How epigenetic mechanisms might regulate these mutualistic interactions is unknown. By manipulating the level of expression of the chromatin remodeler DECREASE IN DNA METHYLATION 1 (DDM1) and two demethylases DEMETER-LIKE (DML) in Populus tremula × Populus alba lines, we examined how host DNA methylation modulates multiple parameters of the responses to root colonization with the mutualistic fungus Laccaria bicolor. We compared the ectomycorrhizas formed between transgenic and wild-type (WT) trees and analyzed their methylomes and transcriptomes. The poplar lines displaying lower mycorrhiza formation rate corresponded to hypomethylated overexpressing DML or RNAi-ddm1 lines. We found 86 genes and 288 transposable elements (TEs) differentially methylated between WT and hypomethylated lines (common to both OX-dml and RNAi-ddm1) and 120 genes/1441 TEs in the fungal genome suggesting a host-induced remodeling of the fungal methylome. Hypomethylated poplar lines displayed 205 differentially expressed genes (cis and trans effects) in common with 17 being differentially methylated (cis). Our findings suggest a central role of host and fungal DNA methylation in the ability to form ectomycorrhizas including not only poplar genes involved in root initiation, ethylene and jasmonate-mediated pathways, and immune response but also terpenoid metabolism.


Assuntos
Laccaria , Micorrizas , Populus , Micorrizas/fisiologia , Árvores/genética , Árvores/metabolismo , Raízes de Plantas/metabolismo , Metilação de DNA/genética , DNA , Populus/metabolismo , Laccaria/genética
19.
Mol Phylogenet Evol ; 189: 107938, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37820761

RESUMO

The order Sordariales is taxonomically diverse, and harbours many species with different lifestyles and large economic importance. Despite its importance, a robust genome-scale phylogeny, and associated comparative genomic analysis of the order is lacking. In this study, we examined whole-genome data from 99 Sordariales, including 52 newly sequenced genomes, and seven outgroup taxa. We inferred a comprehensive phylogeny that resolved several contentious relationships amongst families in the order, and cleared-up intrafamily relationships within the Podosporaceae. Extensive comparative genomics showed that genomes from the three largest families in the dataset (Chaetomiaceae, Podosporaceae and Sordariaceae) differ greatly in GC content, genome size, gene number, repeat percentage, evolutionary rate, and genome content affected by repeat-induced point mutations (RIP). All genomic traits showed phylogenetic signal, and ancestral state reconstruction revealed that the variation of the properties stems primarily from within-family evolution. Together, the results provide a thorough framework for understanding genome evolution in this important group of fungi.


Assuntos
Genômica , Sordariales , Humanos , Filogenia , Genômica/métodos , Genoma , Sordariales/genética , Sequência de Bases , Evolução Molecular
20.
Respirology ; 28(11): 1069-1077, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37587548

RESUMO

BACKGROUND AND OBJECTIVE: Continuous positive airway pressure (CPAP) in the treatment of severe obstructive sleep apnoea (OSA) can be used in fixed CPAP or auto-adjusted (APAP) mode. The aim of this prospective randomized controlled clinical study was to evaluate the 3 month-efficacy of CPAP used either in fixed CPAP or APAP mode. METHODS: Eight hundred one patients with severe OSA were included in twenty-two French centres. After 7 days during which all patients were treated with APAP to determine the effective pressure level and its variability, 353 and 351 patients were respectively randomized in the fixed CPAP group and APAP group. After 3 months of treatment, 308 patients in each group were analysed. RESULTS: There was no difference between the two groups in terms of efficacy whatever the level of efficient pressure and pressure variability (p = 0.41). Exactly, 219 of 308 patients (71.1%) in the fixed CPAP group and 212 of 308 (68.8%) in the APAP group (p = 0.49) demonstrated residual apnoea hypopnoea index (AHI) <10/h and Epworth Score <11. Tolerance and adherence were also identical with a similar effect on quality of life and blood pressure evaluation. CONCLUSION: The two CPAP modes, fixed CPAP and APAP, were equally effective and tolerated in severe OSA patients.


Assuntos
Apneia Obstrutiva do Sono , Humanos , Apneia Obstrutiva do Sono/terapia , Qualidade de Vida , Pressão Positiva Contínua nas Vias Aéreas , Pressão Sanguínea/fisiologia , Projetos de Pesquisa
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