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1.
Microbiology (Reading) ; 169(2)2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36848210

RESUMO

Sloths have dense fur on which insects, algae, bacteria and fungi coexist. Previous studies using cultivation-dependent methods and 18S rRNA sequencing revealed that the fungal communities in their furs comprise members of the phyla Ascomycota and Basidiomycota. In this note, we increase the resolution and knowledge of the mycobiome inhabiting the fur of the two- (Choloepus hoffmanni) and three-toed (Bradypus variegatus) sloths. Targeted amplicon metagenomic analysis of ITS2 nrDNA sequences obtained from 10 individuals of each species inhabiting the same site revealed significant differences in the structure of their fungal communities and also in the alpha-diversity estimators. The results suggest a specialization by host species and that the host effect is stronger than that of sex, age and animal weight. Capnodiales were the dominant order in sloths' fur and Cladosporium and Neodevriesia were the most abundant genera in Bradypus and Choloepus, respectively. The fungal communities suggest that the green algae that inhabit the fur of sloths possibly live lichenized with Ascomycota fungal species. The data shown in this note offer a more detailed view of the fungal content in the fur of these extraordinary animals and could help explain other mutualistic relationships in this complex ecosystem.


Assuntos
Micobioma , Bichos-Preguiça , Animais , Ecossistema , Especificidade de Hospedeiro , Metagenômica
2.
J Appl Microbiol ; 134(5)2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37113015

RESUMO

AIMS: The American leaf spot, caused by Mycena citricolor, is an important disease of coffee (Coffea arabica), mostly in Central America. Currently, there are limited pathogen control alternatives that are environment friendly and economically accessible. The use of fungi isolated from the plant endomycobiota in their native habitats is on the rise because studies show their great potential for biological control. To begin to generate a green alternative to control M. citricolor, the objectives of the present study were to (i) collect, identify, screen (in vitro and in planta), and select endophytic fungi from wild Rubiaceae collected in old-growth forests of Costa Rica; (ii) confirm endophytic colonization in coffee plantlets; (iii) evaluate the effects of the endophytes on plantlet development; and (iv) corroborate the antagonistic ability in planta. METHODS AND RESULTS: Through in vitro and in planta antagonism assays, we found that out of the selected isolates (i.e. Daldinia eschscholzii GU11N, Nectria pseudotrichia GUHN1, Purpureocillium aff. lilacinum CT24, Sarocladium aff. kiliense CT25, Trichoderma rifaii CT5, T. aff. crassum G1C, T. aff. atroviride G7T, T. aff. strigosellum GU12, and Xylaria multiplex GU14T), Trichoderma spp. produced the highest growth inhibition percentages in vitro. Trichoderma isolates CT5 and G1C were then tested in planta using Coffea arabica cv. caturra plantlets. Endophytic colonization was verified, followed by in planta growth promotion and antagonism assays. CONCLUSIONS: Results show that Trichoderma isolates CT5 and G1C have potential for plant growth promotion and antagonism against Mycena citricolor, reducing incidence and severity, and preventing plant mortality.


Assuntos
Agaricales , Coffea , Rubiaceae , Café , Fungos , Coffea/microbiologia
3.
Plant Dis ; 107(9): 2816-2824, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36802295

RESUMO

Global agricultural trade has accelerated the emergence and re-emergence of new plant pathogens. In the United States, the fungal pathogen Colletotrichum liriopes is still considered a foreign quarantine pathogen that affects ornamental plants (i.e., Liriope spp.). Even though this species has been reported in East Asia on various asparagaceous hosts, its first and only report in the United States was in 2018. However, that study used only ITS nrDNA for identification, and no available culture or voucher specimen was maintained. The main objective of the present study was to determine the geographic and host distribution of specimens identified as C. liriopes. To accomplish this, new and existing isolates, sequences, and genomes obtained from various hosts and geographic locations (i.e., China, Colombia, Mexico, and the United States) were compared with the ex-type of C. liriopes. Multilocus phylogenetic (ITS, Tub2, GAPDH, CHS-1, and HIS3), phylogenomic, and splits tree analyses revealed that all the studied isolates/sequences form a well-supported clade with little intraspecific variation. Morphological characterizations support these findings. The minimum spanning network, low nucleotide diversity, and negative Tajima's D from both multilocus and genomic data suggest that there was a recent movement/invasion of a few East Asian genotypes to other countries where the ornamental plants are produced (e.g., South America) and subsequently to the importing countries, such as the United States. The study reveals that the geographic and host distribution of C. liriopes sensu stricto is expanded to the United States (i.e., at least Maryland, Mississippi, and Tennessee) and on various hosts in addition to Asparagaceae and Orchidaceae. The present study produces fundamental knowledge that can be used in efforts to reduce costs or losses from agricultural trade and to expand our understanding of pathogen movement.


Assuntos
Doenças das Plantas , Quarentena , Estados Unidos , Filogenia , Doenças das Plantas/microbiologia , Mississippi
4.
J Invertebr Pathol ; 192: 107787, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35697117

RESUMO

Hypocrella, Moelleriella and related species in the Hypocreales (Ascomycota, Sordariomycetes) cause epizootics of whiteflies and scale insects in nature. However, studies on their host specificity, virulence, infection cycles, optimal development under laboratory conditions, and compatibility with other control methods, are unexplored for most species. Under laboratory conditions, the virulence of several isolates of field-collected hypocrealean fungi (Hypocrella, Moelleriella, Regiocrella, and Verticillium) was determined on Bemisia tabaci eggs and 4th instar nymphs. In addition to virulence, the effect of temperature and two commercial fungicides on growth rates and germination of the isolates was evaluated. None of the isolates infected the eggs, while M. libera, M. ochracea, and M. turbinata caused high nymphal mortality. Moelleriella libera was the most virulent isolate. At all temperatures, M. libera, Regiocrella sp. (P17H20), and Verticillium cf. pseudohemipterigenum had the highest germination and growth rates. The optimal growth temperature depended on the isolate, but at 23 °C and 25 °C, the probability of spore germination was higher for most isolates. Finally, the fungicides azoxystrobin and chlorothalonil inhibited growth rates and conidial germination at 24 and 48 h of exposure. This research produces vital knowledge on the virulence and infection cycles of poorly studied native species of entomopathogenic fungi. In addition, the results provide information on the optimal temperature for development in laboratory conditions and susceptibility to fungicides, which could contribute to future biological control strategies.


Assuntos
Fungicidas Industriais , Hemípteros , Hypocreales , Animais , Fungicidas Industriais/farmacologia , Hemípteros/microbiologia , Ninfa , Controle Biológico de Vetores/métodos , Temperatura , Virulência
5.
Phytopathology ; 109(11): 1888-1899, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31290729

RESUMO

The Corynespora leaf fall disease of rubber trees, caused by the necrotrophic fungus Corynespora cassiicola, is responsible for important yield losses in Asian and African plantations, whereas its impact is negligible in South America. The objective of this study was to identify potential antagonists of C. cassiicola among fungal endophytes (i.e., Pestalotiopsis, Colletotrichum, and Trichoderma spp.) isolated from wild and cultivated rubber trees distributed in the Peruvian Amazon. We first tested the endophytes in dual in vitro confrontation assays against a virulent C. cassiicola isolate (CCP) obtained from diseased rubber trees in the Philippines. All Trichoderma isolates overran the CCP colony, suggesting some antagonistic mechanism, while species from the other genera behaved as mutual antagonists. Trichoderma isolates were then tested through antibiosis assays for their capacity to produce growth-inhibiting molecules. One isolate (LA279), recovered as an endophyte from a wild Hevea guianensis specimen and identified as Trichoderma koningiopsis, showed significant antibiosis capacity. We demonstrated that LA279 was also able to endophytically colonize the cultivated rubber tree species (H. brasiliensis). Under controlled laboratory conditions, rubber plants were inoculated with three Trichoderma strains, including LA279, in combination with the pathogenic CCP. Results showed that 1 week preinoculation with the endophytes differentially reduced CCP mycelial development and symptoms. In conclusion, this study suggests that T. koningiopsis isolate LA279-and derivate compounds-could be a promising candidate for the biological control of the important rubber tree pathogen C. cassiicola.


Assuntos
Ascomicetos , Endófitos , Hevea , Doenças das Plantas , Ascomicetos/fisiologia , Endófitos/fisiologia , Filipinas , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , América do Sul
6.
Virol J ; 15(1): 184, 2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30477549

RESUMO

BACKGROUND: Hevea brasiliensis is an important commercial crop due to the high quality of the latex it produces; however, little is known about viral infections in this plant. The only virus described to infect H. brasiliensis until now is a Carlavirus, which was described more than 30 years ago. Virus-derived small interfering RNA (vsiRNAs) are the product of the plant's antiviral defense triggered by dsRNA viral intermediates generated, during the replication cycle. These vsiRNAs are complementar to viral genomes and have been widely used to identify and characterize viruses in plants. METHODS: In the present study, we investigated the virome of leaf and sapwood samples from native H. brasiliensis trees collected in two geographic areas in the Brazilian Amazon. Small RNA (sRNA) deep sequencing and bioinformatic tools were used to assembly, identify and characterize viral contigs. Subsequently, PCR amplification techniques were performed to experimentally verify the presence of the viral sequences. Finally, the phylogenetic relationship of the putative new virus with related viral genomes was analyzed. RESULTS: Our strategy allowed the identification of 32 contigs with high similarity to viral reference genomes, from which 23 exhibited homology to viruses of the Tymoviridae family. The reads showed a predominant size distribution at 21 nt derived from both strands, which was consistent with the vsiRNAs profile. The presence and genome position of the viral contigs were experimentally confirmed using droplet digital PCR amplifications. A 1913 aa long fragment was obtained and used to infer the phylogenetic relationship of the putative new virus, which indicated that it is taxonomically related to the Grapevine fleck virus, genus Maculavirus. The putative new virus was named Hevea brasiliensis virus (HBrV) in reference to its host. CONCLUSION: The methodological strategy applied here proved to be efficient in detecting and confirming the presence of new viral sequences on a 'very difficult to manage' sample. This is the second time that viral sequences, that could be ascribed as a putative novel virus, associated to the rubber tree has been identified.


Assuntos
Hevea/virologia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA Interferente Pequeno/genética , Perfilação da Expressão Gênica , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Doenças das Plantas/virologia , Folhas de Planta/virologia , Reação em Cadeia da Polimerase , RNA Viral/genética , Análise de Sequência de RNA
7.
Antonie Van Leeuwenhoek ; 109(5): 633-51, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26885975

RESUMO

Fungus-growing "attine" ants forage diverse substrates to grow fungi for food. In addition to the mutualistic fungal partner, the colonies of these insects harbor a rich microbiome composed of bacteria, filamentous fungi and yeasts. Previous work reported some Trichoderma species in the fungus gardens of leafcutter ants. However, no studies systematically addressed the putative association of Trichoderma with attine ants, especially in non-leafcutter ants. Here, a total of 62 strains of Trichoderma were analyzed using three molecular markers (ITS, tef1 and rpb2). In addition, 30 out of 62 strains were also morphologically examined. The strains studied correspond to the largest sampling carried out so far for Trichoderma in the attine ant environment. Our results revealed the richness of Trichoderma in this environment, since we found 20 Trichoderma species, including three new taxa described in the present work (Trichoderma attinorum, Trichoderma texanum and Trichoderma longifialidicum spp. nov.) as well as a new phylogenetic taxon (LESF 545). Moreover, we show that all 62 strains grouped within different clades across the Trichoderma phylogeny, which are identical or closely related to strains derived from several other environments. This evidence supports the transient nature of the genus Trichoderma in the attine ant colonies. The discovery of three new species suggests that the dynamic foraging behavior of these insects might be responsible for accumulation of transient fungi into their colonies, which might hold additional fungal taxa still unknown to science.


Assuntos
Formigas/microbiologia , Trichoderma/classificação , Animais , Sequência de Bases , Microbiologia Ambiental , Microbiota , Filogenia , Reação em Cadeia da Polimerase/métodos , Microbiologia do Solo , Esporos Fúngicos/citologia , Simbiose , Trichoderma/citologia , Trichoderma/genética , Trichoderma/isolamento & purificação
8.
Mycologia ; 107(2): 284-97, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25572095

RESUMO

Research on fungal endophytes has expanded dramatically in recent years, but little is known about the diversity and ecological roles of endophytic basidiomycetes. Here we report the analysis of 310 basidiomycetous endophytes isolated from wild and planted populations of the rubber tree genus, Hevea. Species accumulation curves were nonasymptotic, as in the majority of endophyte surveys, indicating that more sampling is needed to recover the true diversity of the community. One hundred eighteen OTUs were delimited, representing nine orders of Basidiomycota (Agaricales, Atheliales, Auriculariales, Cantharellales, Hymenochaetales, Polyporales, Russulales, Septobasidiales, Tremellales). The diversity of basidiomycetous endophytes found inhabiting wild populations of Hevea was comparable to that present in plantations. However, when samples were segregated by tissue type, sapwood of wild populations was found to contain a higher number of species than sapwood of planted trees. Seventy-five percent of isolates were members of the Polyporales, the majority in the phlebioid clade. Most of the species belong to clades known to cause a white-rot type of wood decay. Two species in the insect-associated genus Septobasidium were isolated. The most frequently isolated genera included Bjerkandera, Ceriporia, Phanerochaete, Phlebia, Rigidoporus, Tinctoporellus, Trametes (Polyporales), Peniophora, Stereum (Russulales) and Coprinellus (Agaricales), all of which have been reported as endophytes from a variety of hosts, across wide geographic locations. Literature records on the geographic distribution and host association of these genera revealed that their distribution and substrate affinity could be extended if the endophytic niche was investigated as part of fungal biodiversity surveys.


Assuntos
Basidiomycota/isolamento & purificação , Biodiversidade , Endófitos/isolamento & purificação , Hevea/microbiologia , Folhas de Planta/microbiologia , Madeira/microbiologia , Basidiomycota/classificação , Basidiomycota/genética , Endófitos/classificação , Endófitos/genética , Dados de Sequência Molecular , Filogenia
9.
Mycologia ; 107(3): 558-590, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25661720

RESUMO

Trichoderma harzianum is known as a cosmopolitan, ubiquitous species associated with a wide variety of substrates. It is possibly the most commonly used name in agricultural applications involving Trichoderma, including biological control of plant diseases. While various studies have suggested that T. harzianum is a species complex, only a few cryptic species are named. In the present study the taxonomy of the T. harzianum species complex is revised to include at least 14 species. Previously named species included in the complex are T. guizhouense, T. harzianum, and T. inhamatum. Two new combinations are proposed, T. lentiforme and T. lixii. Nine species are described as new, T. afarasin, T. afroharzianum, T. atrobrunneum, T. camerunense, T. endophyticum, T. neotropicale, T. pyramidale, T. rifaii and T. simmonsii. We isolated Trichoderma cultures from four commercial biocontrol products reported to contain T. harzianum. None of the biocontrol strains were identified as T. harzianum s. str. In addition, the widely applied culture 'T. harzianum T22' was determined to be T. afroharzianum. Some species in the T. harzianum complex appear to be exclusively endophytic, while others were only isolated from soil. Sexual states are rare. Descriptions and illustrations are provided. A secondary barcode, nuc translation elongation factor 1-α (TEF1) is needed to identify species in this complex.


Assuntos
Inoculantes Agrícolas/classificação , Trichoderma/classificação , Inoculantes Agrícolas/genética , Inoculantes Agrícolas/crescimento & desenvolvimento , Inoculantes Agrícolas/isolamento & purificação , DNA Fúngico/genética , DNA Ribossômico/genética , Proteínas Fúngicas/genética , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos/genética , Controle Biológico de Vetores/economia , Filogenia , Microbiologia do Solo , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação , Trichoderma/genética , Trichoderma/crescimento & desenvolvimento , Trichoderma/isolamento & purificação
10.
Mycologia ; 107(3): 532-57, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25800252

RESUMO

The genus Cosmospora includes nectrioid fungi that grow on polypores and xylariaceous fungi. The collections growing on xylariaceous fungi have been identified recently as Cosmospora viliuscula. In this paper the phylogeny and taxonomy of C. viliuscula are investigated. A phylogeny was generated with maximum likelihood and Bayesian inference methods applied to a three-partition dataset (ITS, 28S, MCM7-RPB1-TUB2). Based on these results, we demonstrate that Cosmospora viliuscula represents a diverse species complex comprising more than 10 species. Seven new species are described, including three single-strain lineages, and the sexual states of C. arxii and C. khandalensis are described for the first time. The sexual states of these fungi tend to have a high degree of morphological homoplasy, making it difficult to differentiate among them based on morphological characters alone. However, the apparent host specificity of species in this complex aide in the diagnosis of these fungi. In addition, the RPB1 marker provides sufficient resolution to distinguish these fungi.


Assuntos
Hypocreales/classificação , DNA Fúngico/genética , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Dados de Sequência Molecular , Filogenia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento
11.
Chem Biodivers ; 12(4): 662-84, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25879509

RESUMO

The production of bioactive polypeptides (peptaibiotics) in vivo is a sophisticated adaptation strategy of both mycoparasitic and saprotrophic Trichoderma species for colonizing and defending their natural habitats. This feature is of major practical importance, as the detection of peptaibiotics in plant-protective Trichoderma species, which are successfully used against economically relevant bacterial and fungal plant pathogens, certainly contributes to a better understanding of these complex antagonistic interactions. We analyzed five commercial biocontrol agents (BCAs), namely Canna(®) , Trichosan(®) , Vitalin(®) , Promot(®) WP, and TrichoMax(®) , formulated with recently described species of the Trichoderma harzianum complex, viz. T. afroharzianum, T. simmonsii, and T. guizhouense. By using the well-established, HPLC/MS-based peptaibiomics approach, it could unequivocally be demonstrated that all of these formulations contained new and recurrent peptaibols, i.e., peptaibiotics carrying an acetylated N-terminus, the C-terminus of which is reduced to a 1,2-amino alcohol. Their chain lengths, including the amino alcohol, were 11, 14, and 18 residues, respectively. Peptaibols were also to be the dominating secondary metabolites in plate cultures of the four strains obtained from four of the Trichoderma- based BCAs, contributing 95% of the UHPLC-UV/VIS peak areas and 99% of the total ion count MS peak area from solid media. Furthermore, species-specific hydrophobins, as well as non-peptaibiotic secondary metabolites, were detected, the latter being known for their antifungal, siderophore, or plant-growth-promoting activities. Notably, none of the isolates produced low-molecular weight mycotoxins.


Assuntos
Agentes de Controle Biológico/análise , Peptaibols/análise , Metabolismo Secundário , Trichoderma , Aminoácidos/análise , Cromatografia Líquida de Alta Pressão , Peso Molecular , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrofotometria Ultravioleta , Trichoderma/metabolismo
12.
Mycologia ; 106(6): 1090-105, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24987126

RESUMO

The objective of this study was to identify a group of unknown endophytic fungal isolates from the living sapwood of wild and planted Hevea (rubber tree) populations. Three novel lineages of Tolypocladium are described based on molecular and morphological data. Findings from this study open a window for novel hypotheses regarding the ecology and role of endophytes within plant communities as well as trait evolution and potential forces driving diversification of Cordyceps-like fungi. This study stresses the importance of integrating asexual and sexual fungal states for a more complete understanding of the natural history of this diverse group. In addition, it highlights the study of fungi in the sapwood of tropical trees as habitat for the discovery of novel fungal lineages and substrate associations.


Assuntos
Hevea/microbiologia , Hypocreales/classificação , Evolução Biológica , Cordyceps , Ecologia , Endófitos , Especificidade de Hospedeiro , Hypocreales/genética , Hypocreales/isolamento & purificação , Hypocreales/fisiologia , Filogenia , Análise de Sequência de DNA , Esporos Fúngicos , Simbiose
13.
Nat Microbiol ; 9(2): 336-345, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38316926

RESUMO

microbeMASST, a taxonomically informed mass spectrometry (MS) search tool, tackles limited microbial metabolite annotation in untargeted metabolomics experiments. Leveraging a curated database of >60,000 microbial monocultures, users can search known and unknown MS/MS spectra and link them to their respective microbial producers via MS/MS fragmentation patterns. Identification of microbe-derived metabolites and relative producers without a priori knowledge will vastly enhance the understanding of microorganisms' role in ecology and human health.


Assuntos
Metabolômica , Espectrometria de Massas em Tandem , Humanos , Metabolômica/métodos , Bases de Dados Factuais
14.
Mycologia ; 105(5): 1287-305, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23921243

RESUMO

Cosmospora sensu Rossman accommodated nectroid fungi with small, reddish, smooth, thin-walled perithecia but recently was found to be polyphyletic and has been segregated into multiple genera. Not all cosmospora-like fungi have been treated systematically. Some of these species include C. vilior and many specimens often labeled "Cosmospora sp." The objectives of this research were to establish the identity of C. vilior through epitypication using a recent collection that agrees with the type specimen in morphology, host and geography and to determine its phylogenetic position within Cosmospora sensu lato and the Nectriaceae. A multilocus phylogeny was constructed based on six loci (ITS, LSU, MCM7, rpb1, tef1, tub) to estimate a phylogeny. Results from the phylogenetic analyses indicated that C. vilior forms a monophyletic group with other cosmospora-like fungi that have an acremonium-like anamorph and that parasitize Eutypa and Eutypella (Ascomycota, Sordariomycetes, Xylariales, Diatrypaceae). The group is phylogenetically distinct from other previously segregated genera. A new genus, Pseudocosmospora, is described to accommodate the type species, P. eutypellae, and nine additional species in this clade.


Assuntos
Hypocreales/classificação , Filogenia , Esporos Fúngicos/citologia , Sequência de Bases , DNA Fúngico/genética , DNA Ribossômico/genética , Genes Fúngicos/genética , Hypocreales/citologia , Hypocreales/genética , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
15.
PLoS One ; 18(1): e0279914, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36652424

RESUMO

We studied the physicochemical characteristics and mycobiota associated to five key historic documents from Costa Rica, including the Independence Act of Costa Rica from 1821. We used nondestructive techniques (i.e., ATR-FTIR and XRF) to determine paper and ink composition. Results show that some documents are composed of cotton-based paper, whereas others were made of wood cellulose with an increased lignin content. We also determined that the ink employed in some of the documents is ferrogallic. Cultivation and molecular techniques were used to characterize the fungi inhabiting the documents. In total, 22 fungal isolates were obtained: 15 from the wood-cellulose-based documents and seven from the other three cotton-based. We also tested the cellulolytic activity of the recovered fungi; 95% of the fungi presented cellulolytic activity correlated to their ability to cause deterioration of the paper. Results suggest that cotton-based paper is the most resistant to fungal colonization and that most of the isolates have cellulolytic activity. This work increases the knowledge of the fungal diversity that inhabits historic documents and its relationship with paper composition and provides valuable information to develop strategies to conserve and restore these invaluable documents.


Assuntos
Celulose , Fungos , Costa Rica , Lignina , Madeira
16.
ACS Omega ; 8(34): 31373-31388, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37663497

RESUMO

Fungi exhibit a wide range of ecological guilds, but those that live within the inner tissues of plants (also known as endophytes) are particularly relevant due to the benefits they sometimes provide to their hosts, such as herbivory deterrence, disease protection, and growth promotion. Recently, endophytes have gained interest as potential biocontrol agents against crop pathogens, for example, coffee plants (Coffea arabica). Published results from research performed in our laboratory showed that endophytic fungi isolated from wild Rubiaceae plants were effective in reducing the effects of the American leaf spot of coffee (Mycena citricolor). One of these isolates (GU11N) from the plant Randia grandifolia was identified as Daldinia eschscholtzii (Xylariales). Its antagonism mechanisms, effects, and chemistry against M. citricolor were investigated by analyzing its volatile profile alone and in the presence of the pathogen in contactless and dual culture assays. The experimental design involved direct sampling of agar plugs in vials for headspace (HS) and headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) analysis. Additionally, we used ultrahigh-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS) to identify nonvolatile compounds from organic extracts of the mycelia involved in the interaction. Results showed that more volatile compounds were identified using HS-SPME (39 components) than those by the HS technique (13 components), sharing only 12 compounds. Statistical tests suggest that D. eschscholtzii inhibited the growth of M. citricolor through the release of VOCs containing a combination of 1,8-dimethoxynapththalene and terpene compounds affecting M. citricolor pseudopilei. The damaging effects of 1,8-dimethoxynaphthalene were corroborated in an in vitro test against M. citricolor pseudopilei; scanning electron microscopy (SEM) photographs confirmed structural damage. After analyzing the UHPLC-HRMS/MS data, a predominance of fatty acid derivatives was found among the putatively identified compounds. However, a considerable proportion of features (37.3%) remained unannotated. In conclusion, our study suggests that D. eschscholtzii has potential as a biocontrol agent against M. citricolor and that 1,8-dimethoxynaphthalene contributes to the observed damage to the pathogen's reproductive structures.

17.
PLoS One ; 18(12): e0289280, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38127903

RESUMO

Trichoderma is a cosmopolitan genus with diverse lifestyles and nutritional modes, including mycotrophy, saprophytism, and endophytism. Previous research has reported greater metabolic gene repertoires in endophytic fungal species compared to closely-related non-endophytes. However, the extent of this ecological trend and its underlying mechanisms are unclear. Some endophytic fungi may also be mycotrophs and have one or more mycoparasitism mechanisms. Mycotrophic endophytes are prominent in certain genera like Trichoderma, therefore, the mechanisms that enable these fungi to colonize both living plants and fungi may be the result of expanded metabolic gene repertoires. Our objective was to determine what, if any, genomic features are overrepresented in endophytic fungi genomes in order to undercover the genomic underpinning of the fungal endophytic lifestyle. Here we compared metabolic gene cluster and mycoparasitism gene diversity across a dataset of thirty-eight Trichoderma genomes representing the full breadth of environmental Trichoderma's diverse lifestyles and nutritional modes. We generated four new Trichoderma endophyticum genomes to improve the sampling of endophytic isolates from this genus. As predicted, endophytic Trichoderma genomes contained, on average, more total biosynthetic and degradative gene clusters than non-endophytic isolates, suggesting that the ability to create/modify a diversity of metabolites potential is beneficial or necessary to the endophytic fungi. Still, once the phylogenetic signal was taken in consideration, no particular class of metabolic gene cluster was independently associated with the Trichoderma endophytic lifestyle. Several mycoparasitism genes, but no chitinase genes, were associated with endophytic Trichoderma genomes. Most genomic differences between Trichoderma lifestyles and nutritional modes are difficult to disentangle from phylogenetic divergences among species, suggesting that Trichoderma genomes maybe particularly well-equipped for lifestyle plasticity. We also consider the role of endophytism in diversifying secondary metabolism after identifying the horizontal transfer of the ergot alkaloid gene cluster to Trichoderma.


Assuntos
Endófitos , Trichoderma , Endófitos/genética , Trichoderma/genética , Filogenia , Plantas/genética , Família Multigênica/genética , Fungos/genética
18.
Res Sq ; 2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37577622

RESUMO

MicrobeMASST, a taxonomically-informed mass spectrometry (MS) search tool, tackles limited microbial metabolite annotation in untargeted metabolomics experiments. Leveraging a curated database of >60,000 microbial monocultures, users can search known and unknown MS/MS spectra and link them to their respective microbial producers via MS/MS fragmentation patterns. Identification of microbial-derived metabolites and relative producers, without a priori knowledge, will vastly enhance the understanding of microorganisms' role in ecology and human health.

19.
Mycologia ; 104(6): 1325-50, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22778168

RESUMO

Thelonectria is a recently established genus of common and ubiquitous fungi on woody hosts, previously placed in the genus Neonectria. Thelonectria coronata and T. veuillotiana occur sympatrically in tropical, subtropical and temperate regions. Previous taxonomic studies including T. coronata and T. veuillotiana suggested these fungi could represent species complexes; however, the morphological features used to define species exhibited few differences useful for testing this hypothesis. To assess the status of T. coronata and T. veuillotiana, phylogenetic analyses of six genomic regions were combined with a morphological examination of specimens. A multi-gene phylogeny reconstructed with maximum parsimony, maximum likelihood and Bayesian approaches identified five phylogenetic groups in T. coronata and six in T. veuillotiana. As is common for cryptic species, unequivocal diagnostic morphological characters could not be identified; however, average values of morphological traits correspond to the phylogenetic groups. An increased number of non-synonymous/synonymous substitutions in the ß-tubu-lin gene and a decreased or absent production of conidia were detected within the T. coronata complex, possibly indicating the homothallic nature of these isolates. T. coronata and T. veuillotiana and related species are described and illustrated here; a dichotomous key to all species is provided.


Assuntos
Ascomicetos/classificação , Filogenia , Actinas/genética , Ascomicetos/citologia , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Sequência de Bases , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Proteínas Fúngicas/genética , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Elongação Traducional da Cadeia Peptídica/genética , RNA Polimerase II/genética , Análise de Sequência de DNA , Esporos Fúngicos/classificação , Esporos Fúngicos/citologia , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação , Tubulina (Proteína)/genética
20.
Anim Microbiome ; 4(1): 24, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35303964

RESUMO

BACKGROUND: Bats are important long-distance dispersers of many tropical plants, yet, by consuming fruits, they may disperse not only the plant's seeds, but also the mycobiota within those fruits. We characterized the culture-dependent and independent fungal communities in fruits of Ficus colubrinae and feces of Ectophylla alba to determine if passage through the digestive tract of bats affected the total mycobiota. RESULTS: Using presence/absence and normalized abundance data from fruits and feces, we demonstrate that the fungal communities were significantly different, even though there was an overlap of ca. 38% of Amplicon Sequence Variants (ASVs). We show that some of the fungi from fruits were also present and grew from fecal samples. Fecal fungal communities were dominated by Agaricomycetes, followed by Dothideomycetes, Sordariomycetes, Eurotiomycetes, and Malasseziomycetes, while fruit samples were dominated by Dothideomycetes, followed by Sordariomycetes, Agaricomycetes, Eurotiomycetes, and Laboulbeniomycetes. Linear discriminant analyses (LDA) show that, for bat feces, the indicator taxa include Basidiomycota (i.e., Agaricomycetes: Polyporales and Agaricales), and the ascomycetous class Eurotiomycetes (i.e., Eurotiales, Aspergillaceae). For fruits, indicator taxa are in the Ascomycota (i.e., Dothideomycetes: Botryosphaeriales; Laboulbeniomycetes: Pyxidiophorales; and Sordariomycetes: Glomerellales). In our study, the differences in fungal species composition between the two communities (fruits vs. feces) reflected on the changes in the functional diversity. For example, the core community in bat feces is constituted by saprobes and animal commensals, while that of fruits is composed mostly of phytopathogens and arthropod-associated fungi. CONCLUSIONS: Our study provides the groundwork to continue disentangling the direct and indirect symbiotic relationships in an ecological network that has not received enough attention: fungi-plants-bats. Findings also suggest that the role of frugivores in plant-animal mutualistic networks may extend beyond seed dispersal: they may also promote the dispersal of potentially beneficial microbial symbionts while, for example, hindering those that can cause plant disease.

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