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1.
Indian J Med Microbiol ; 44: 100361, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37356829

RESUMO

This study aims to report a rare instance of corneal decompensation brought on by Coniochaeta hoffmannii fungus invasion of a bandage contact lens (BCL). A 71-year-old man with pseudophakic bullous keratopathy (PBK) had BCL treatment for four months to symptomatically reduce pain and itching in his right eye. However, the patient unexpectedly lost his vision. The slit-lamp examination revealed an edematous cornea; the extensive direct inspection raised suspicion of BCL. For morphological characterization, the BCL extracted was inoculated onto 5% sheep blood agar and PDA. By Sanger sequencing method the isolate's genomic DNA was molecularly identified as C. hoffmannii.


Assuntos
Ascomicetos , Bandagens , Lentes de Contato Hidrofílicas , Micoses , Idoso , Humanos , Masculino , Ascomicetos/isolamento & purificação , Ascomicetos/patogenicidade , Bandagens/microbiologia , Cegueira/etiologia , Cegueira/microbiologia , Lentes de Contato Hidrofílicas/microbiologia , Ceratite/etiologia , Ceratite/microbiologia , Manejo da Dor , Prurido/terapia , Micoses/etiologia , Micoses/microbiologia
2.
Microbiol Spectr ; 11(3): e0004223, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37014218

RESUMO

Pestalotioid fungi have been frequently studied with respect to their morphology, molecular phylogeny, and pathogenicity. Monochaetia is a pestalotioid genus that is morphologically characterized by 5-celled conidia with single apical and basal appendages. In the present study, fungal isolates were obtained from diseased leaves of Fagaceae hosts in China in 2016 to 2021 and identified based on morphology and phylogenetic analyses of the 5.8S nuclear ribosomal DNA gene with the two flanking internal transcribed spacer (ITS) regions, the nuclear ribosomal large subunit (LSU) region, the translation elongation factor 1-α (tef1) gene, and the ß-tubulin (tub2) gene. As a result, five new species are proposed here, namely, Monochaetia hanzhongensis, Monochaetia lithocarpi, Monochaetia lithocarpicola, Monochaetia quercicola, and Monochaetia shaanxiensis. In addition, pathogenicity tests for these five species and Monochaetia castaneae from Castanea mollissima were conducted with detached leaves of Chinese chestnut. Results demonstrated that only M. castaneae successfully infected the host C. mollissima and caused brown lesions. IMPORTANCE Monochaetia is a pestalotioid genus, with members that are commonly known as leaf pathogens or saprobes; some strains were isolated from air, in which case their natural substrate is so far unknown. Fagaceae represents an ecologically and economically important plant family that is widely distributed in the Northern Hemisphere, including an important tree crop species, Castanea mollissima, which is widely cultivated in China. In the present study, diseased leaves of Fagaceae in China were investigated, and five new Monochaetia species were introduced based on morphology and phylogeny of combined ITS, LSU, tef1, and tub2 loci. Additionally, six species of Monochaetia were inoculated onto healthy leaves of the crop host Castanea mollissima to test their pathogenicity. The present study provides significant data on the species diversity, taxonomy, and host range of Monochaetia and enhances our understanding of leaf diseases of Fagaceae hosts.


Assuntos
Ascomicetos , Fagaceae , China , DNA Ribossômico , Filogenia , Virulência , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Fagaceae/microbiologia
3.
Sci Rep ; 12(1): 2646, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35173202

RESUMO

Cork oak is a tree species with ecological importance that contributes to economic and social development in the Mediterranean region. Cork oak decline is a major concern for forest sustainability and has negative impacts on cork oak growth and production. This event has been increasingly reported in the last decades and seems to be related with climate changes. Biscogniauxia mediterranea is an endophytic fungus of healthy cork oak trees that turns into a pathogen in trees weaken by environmental stress. Understanding the drivers of B. mediterranea populations diversity and differentiation is expected to allow a better control of cork oak decline and preserve forest sustainability. Endophyte isolates from different cork oak forests were identified as B. mediterranea and their genetic diversity was evaluated using phylogenetic and microsatellite-primed PCR analyses. Genetic diversity and variability of this fungus was correlated with environmental/phytosanitary conditions present in forests/trees from which isolates were collected. High genetic diversity and variability was found in B. mediterranea populations obtained from different forests, suggesting some degree of isolation by distance. Bioclimate was the most significant effect that explained the genetic variability of B. mediterranea, rather than precipitation or temperature intensities alone or disease symptoms. These findings bring new implications for the changing climate to cork oak forests sustainability, cork production and quality.


Assuntos
Ascomicetos/genética , Ascomicetos/patogenicidade , Mudança Climática , Florestas , Variação Genética , Filogenia , Quercus/microbiologia , Ascomicetos/isolamento & purificação , Reação em Cadeia da Polimerase/métodos
4.
Molecules ; 27(3)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35163862

RESUMO

Truffles represent the best known and most expensive edible mushroom. Known as Ascomycetes, they belong to the genus Tuber and live in symbiosis with plant host roots. Due to their extraordinary taste and smell, truffles are sold worldwide for high prices of up to 3000-5000 euros per kilogram (Tuber magnatum PICO). Amongst black truffles, the species Tuber melanosporum VITTAD. is highly regarded for its organoleptic properties. Nonetheless, numerous different sorts of black truffle are offered at lower prices, including Tuber aestivum VITTAD., Tuber indicum and Tuber uncinatum, which represent the most frequently consumed types. Because truffles do not differ visually for inexperienced consumers, food fraud is likely to occur. In particular, for the highly prized Tuber melanosporum, which morphologically forms very similar fruiting bodies to those of Tuber indicum, there is a risk of fraud via imported truffles from Asia. In this study, 126 truffle samples belonging to the four mentioned species were investigated by four different NIR instruments, including three miniaturized devices-the Tellspec Enterprise Sensor, the VIAVI solutions MicroNIR 1700 and the Consumer Physics SCiO-working on different technical principles. Three different types of measurement techniques were applied for all instruments (outer shell, rotational device and fruiting body) in order to identify the best results for classification and quality assurance in a non-destructive manner. Results provided differentiation with an accuracy up to 100% for the expensive Tuber melanosporum from Tuber indicum. Classification between Tuber melanosporum, Tuber indicum, Tuber aestivum and Tuber uncinatum could also be achieved with success of 100%. In addition, quality monitoring including discrimination between fresh and frozen/thawed, and prediction of the approximate date of harvesting, was performed. Furthermore, feasibility studies according to the geographical origin of the truffle were attempted. The presented work compares the performance for prediction and quality monitoring of portable vs. benchtop NIR devices and applied measurement techniques in order to be able to present a suitable, accurate, fast, non-destructive and reliable method for consumers.


Assuntos
Ascomicetos/química , Ascomicetos/classificação , Técnicas Biossensoriais/métodos , Contaminação de Alimentos/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Ascomicetos/isolamento & purificação , Especificidade da Espécie
5.
Sci Rep ; 12(1): 780, 2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-35039545

RESUMO

Fungal endophytes have the capacity to biosynthesize secondary metabolites that are produced by their host plants. In this study, a dilactone terpenoid of C16 architecture was isolated from the fungal endophytes of Kigelia africana, in our attempt to identify anti-Pseudomonas aeruginosa metabolites. Thirty-eight fungal isolates were cultured for biomolecule production over a period of thirty days. Extracts from three (ZF 34, ZF 52 and ZF 91) of the fungi showed good anti-P. aeruginosa activity, with ZF 52 presenting the best MIC of 19.53 µg/mL and was accordingly subjected to chromatographic separation. Based on nuclear magnetic resonance (NMR) spectroscopy, high resolution mass spectrometry and single crystal X-ray diffraction (XRD) analyses, the isolated compound was identified as a C16-terpene dilactone, with a structure consistent with that of the known diterpene, CJ-14445. The isolated dilactone showed anti-P. aeruginosa activity with MIC of 0.61 µg/mL, signifying the antibacterial potential of the biomolecule. The bioactive fungal isolate (ZF 52) was identified as Neofusicoccum luteum based on genomic DNA sequencing. This is the first report of the endophyte N. luteum from K. africana and the first reported occurrence of CJ-14445 in the fungus.


Assuntos
Ascomicetos/metabolismo , Bignoniaceae/microbiologia , Endófitos/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Terpenos/isolamento & purificação , Terpenos/farmacologia , Ascomicetos/isolamento & purificação , Farmacorresistência Bacteriana , Terpenos/química , Terpenos/metabolismo
7.
Chest ; 160(6): e639-e643, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34872678

RESUMO

CASE PRESENTATION: A 31-year-old man was admitted to our hospital with a recent history of generalized seizures. Three months earlier, he started with intermittent hemoptysis. CT scan showed a cavitary lung lesion in the upper segment of the right inferior lobe (RIL). Because of his job as a social worker in a high-risk population, he started treatment for Mycobacterium TB; however, the BAL culture result was negative. At the time of his current admission, he has continued taking rifampicin, isoniazid, pyrazinamide, and levofloxacin. He denied the use of any illicit drugs or alcohol. He had no history of smoking. One year earlier, he visited Southeast Asia, Oceania, and South Africa for several months. He reported a weight loss of 7 kg since then. Except for a recurrent oral candidiasis, he did not have a relevant medical history. His family history was notable for mother with lupus, and brother with sarcoidosis.


Assuntos
Ascomicetos/isolamento & purificação , Encefalopatias/microbiologia , Doença Granulomatosa Crônica/imunologia , Pneumopatias Fúngicas/microbiologia , Adulto , Antifúngicos/uso terapêutico , Encefalopatias/tratamento farmacológico , Diagnóstico Diferencial , Humanos , Hospedeiro Imunocomprometido , Pneumopatias Fúngicas/tratamento farmacológico , Imageamento por Ressonância Magnética , Masculino , Convulsões/microbiologia , Tomografia Computadorizada por Raios X
8.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34731078

RESUMO

A growing interest in fungi that occur within symptom-less plants and lichens (endophytes) has uncovered previously uncharacterized species in diverse biomes worldwide. In many temperate and boreal forests, endophytic Coniochaeta (Sacc.) Cooke (Coniochaetaceae, Coniochaetales, Sordariomycetes, Ascomycota) are commonly isolated on standard media, but rarely are characterized. We examined 26 isolates of Coniochaeta housed at the Gilbertson Mycological Herbarium. The isolates were collected from healthy photosynthetic tissues of conifers, angiosperms, mosses and lichens in Canada, Sweden and the United States. Their barcode sequences (nuclear ribosomal internal transcribed spacer and 5.8S; ITS rDNA) were ≤97% similar to any documented species available through GenBank. Phylogenetic analyses based on two loci (ITS rDNA and translation elongation factor 1-alpha) indicated that two isolates represented Coniochaeta cymbiformispora, broadening the ecological niche and geographic range of a species known previously from burned soil in Japan. The remaining 24 endophytes represented three previously undescribed species that we characterize here: Coniochaeta elegans sp. nov., Coniochaeta montana sp. nov. and Coniochaeta nivea sp. nov. Each has a wide host range, including lichens, bryophytes and vascular plants. C. elegans sp. nov. and C. nivea sp. nov. have wide geographic ranges. C. montana sp. nov. occurs in the Madrean biome of Arizona (USA), where it is sympatric with the other species described here. All three species display protease, chitinase and cellulase activity in vitro. Overall, this study provides insight into the ecological and evolutionary diversity of Coniochaeta and suggests that these strains may be amenable for studies of traits relevant to a horizontally transmitted, symbiotic lifestyle.


Assuntos
Ascomicetos , Filogenia , Animais , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Canadá , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Endófitos/classificação , Endófitos/isolamento & purificação , Técnicas de Tipagem Micológica , Análise de Sequência de DNA , Suécia , Estados Unidos
9.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34846290

RESUMO

Exophiala is an important genus, with several species associated with infections in humans and animals. In a survey of soil fungal diversity in Yunnan province, PR China, a novel taxon, Exophiala pseudooligosperma sp. nov., was identified based on combined morphological and molecular phylogenetic features. Morphologically, this species is characterized by having torulose, septate hyphae and swollen, terminal or intercalary conidiogenous cells arising at acute angles from aerial hyphae. Phylogenetic analysis of the combined sequences of the internal transcribed spacer, the small and large nuclear subunit of the rRNA gene and part of the ß-tubulin gene confirmed the phylogenetic position of the new species within the genus Exophiala.


Assuntos
Ascomicetos , Exophiala , Filogenia , Microbiologia do Solo , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Composição de Bases , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Exophiala/genética , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
10.
World J Microbiol Biotechnol ; 37(11): 190, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34632549

RESUMO

Considering that current biotechnological advances have been contributing towards improving the well-being of humanity, endophytic fungi, such as Lasiodiplodia, are promising sources of new substances to be used in chemical, pharmaceutical and agrochemical processes. Bioactive secondary metabolites are examples of such substances, although it is widely known that Lasiodiplodia inflicts irreparable damage to several crops of major economic importance. They are often produced as a response against biotic and abiotic factors, thus revealing that they play different roles, such as in signaling and defense mechanisms. Therefore, this review presents a few subtle differences between pathogenicity and mutualistic endophyte-host interactions. Moreover, the main secondary metabolites produced by Lasiodiplodia endophytes have been described with respect to their relevant antimicrobial and cytotoxic activities.


Assuntos
Ascomicetos/metabolismo , Ascomicetos/patogenicidade , Animais , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/metabolismo , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Biotecnologia , Produtos Agrícolas , Endófitos/metabolismo , Endófitos/patogenicidade , Fungos/metabolismo , Humanos , Patologia Vegetal , Simbiose
11.
Microb Genom ; 7(10)2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34617882

RESUMO

Pathogens cause significant challenges to global food security. On annual crops, pathogens must re-infect from environmental sources in every growing season. Fungal pathogens have evolved mixed reproductive strategies to cope with the distinct challenges of colonizing growing plants. However, how pathogen diversity evolves during growing seasons remains largely unknown. Here, we performed a deep hierarchical sampling in a single experimental wheat field infected by the major fungal pathogen Zymoseptoria tritici. We analysed whole genome sequences of 177 isolates collected from 12 distinct cultivars replicated in space at three time points of the growing season to maximize capture of genetic diversity. The field population was highly diverse with 37 SNPs per kilobase, a linkage disequilibrium decay within 200-700 bp and a high effective population size. Using experimental infections, we tested a subset of the collected isolates on the dominant cultivar planted in the field. However, we found no significant difference in virulence of isolates collected from the same cultivar compared to isolates collected on other cultivars. About 20 % of the isolate genotypes were grouped into 15 clonal groups. Pairs of clones were disproportionally found at short distances (<5 m), consistent with experimental estimates for per-generation dispersal distances performed in the same field. This confirms predominant leaf-to-leaf transmission during the growing season. Surprisingly, levels of clonality did not increase over time in the field although reproduction is thought to be exclusively asexual during the growing season. Our study shows that the pathogen establishes vast and stable gene pools in single fields. Monitoring short-term evolutionary changes in crop pathogens will inform more durable strategies to contain diseases.


Assuntos
Ascomicetos/genética , Fungos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Doenças das Plantas/microbiologia , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Genótipo , Filogenia , Folhas de Planta/microbiologia , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Reprodução , Virulência/genética , Sequenciamento Completo do Genoma
12.
Microbiol Spectr ; 9(2): e0086721, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34612666

RESUMO

An investigation of members of the soil keratinophilic fungi community in China resulted in the identification of one new monotypic genus, Zongqia, and 10 new species, 2 of which are affiliated with Solomyces, 1 with the new genus Zongqia, 4 with Pseudogymnoascus, and 3 with Scedosporium. These novel taxa form an independent lineage distinct from other species, based on morphological and multilocus phylogenetic analyses. Descriptions, illustrations, and notes are provided for each taxon. These new taxa of the soil keratinophilic fungi add to the increasing number of fungi known from China, and it is now evident that numerous novel taxa are waiting to be described. IMPORTANCE Keratinophilic fungi are a group that can degrade and utilize keratin-rich material. It is also because of this ability that many taxa can cause infections in animals or humans but remain poorly studied. In this study, we reported a novel genus and 10 novel species, 7 novel species belonging to the order Thelebolales and 3 to the genus Scedosporium, based on multilocus phylogenetic analyses combined with morphological characteristics. Our study significantly updates the taxonomy of Thelebolales and Scedosporium and enhances our understanding of this group of the keratin-degrading fungal community. The findings also encourage future studies on the artificially constructed keratin-degrading microbial consortia.


Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Queratinas/metabolismo , Técnicas de Tipagem Micológica/métodos , Ascomicetos/crescimento & desenvolvimento , China , Tipagem de Sequências Multilocus , Micobioma/fisiologia , Solo , Microbiologia do Solo
13.
PLoS One ; 16(10): e0258043, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34653213

RESUMO

Fungal diseases in agronomically important plants such as grapevines result in significantly reduced production, pecuniary losses, and increased use of environmentally damaging chemicals. Beside the well-known diseases, there is an increased interest in wood-colonizing fungal pathogens that infect the woody tissues of grapevines. In 2015, a traditional isolation method was performed on grapevine trunks showing symptoms of trunk diseases in Hungary. One isolate (T15142) was identified as Kalmusia longispora (formerly Dendrothyrium longisporum) according to morphological and phylogenetic analyses. To evaluate the pathogenicity of this fungus on grapevines, artificial infections were carried out under greenhouse and field conditions, including the CBS 824.84 and ex-type CBS 582.83 strains. All isolates could be re-isolated from inoculated plants; however, varying virulence was observed among them in terms of the vascular necrosis caused. The incidence and severity of this symptom seemed to be congruent with the laccase-producing capabilities of the isolates. This is the first report on the ability of Kalmusia longispora to cause symptoms on grapevines, and on its possible dependence on laccase secretion.


Assuntos
Ascomicetos , Lacase/metabolismo , Doenças das Plantas/microbiologia , Vitis/microbiologia , Ascomicetos/isolamento & purificação , Ascomicetos/metabolismo , Ascomicetos/patogenicidade , Virulência
14.
J Microbiol Biotechnol ; 31(11): 1526-1532, 2021 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-34528914

RESUMO

Suaeda australis, Phragmites australis, Suaeda maritima, Suaeda glauca Bunge, and Limonium tetragonum in the Seocheon salt marsh on the west coast of the Korean Penincula were sampled in order to identify the endophytes inhabiting the roots. A total of 128 endophytic fungal isolates belonging to 31 different genera were identified using the fungal internal transcribed spacer (ITS) regions and the 5.8S ribosomal RNA gene. Fusarium, Paraconiothyrium and Alternaria were the most commonly isolated genera in the plant root samples. Various diversity indicators were used to assess the diversity of the isolated fungi. Pure cultures containing each of the 128 endophytic fungi, respectively, were tested for the plant growth-promoting abilities of the fungus on Waito-C rice germinals. The culture filtrate of the isolate Lt-1-3-3 significantly increased the growth of shoots compared to the shoots treated with the control. Lt-1-3-3 culture filtrate was analyzed and showed the presence of gibberellins (GA1 2.487 ng/ml, GA3 2.592 ng/ml, GA9 3.998, and GA24 6.191 ng/ml). The culture filtrate from the Lt-1-3-3 fungal isolate produced greater amounts of GA9 and GA24 than the wild-type Gibberella fujikuroi, a fungus known to produce large amounts of gibberellins. By the molecular analysis, fungal isolate Lt-1-3-3 was identified as Gibberella intermedia, with 100% similarity.


Assuntos
Endófitos/classificação , Plantas Tolerantes a Sal/microbiologia , Alternaria/classificação , Alternaria/isolamento & purificação , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Endófitos/isolamento & purificação , Fusarium/classificação , Fusarium/isolamento & purificação , Giberelinas , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia , RNA Ribossômico 5,8S/genética , República da Coreia , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Áreas Alagadas
15.
Cornea ; 40(10): 1340-1343, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34481411

RESUMO

PURPOSE: To report the clinical and confocal findings of a unique case of combined Phialemonium curvatum and Acanthamoeba keratitis and to highlight the role of the prompt diagnosis and specific medical treatment in preserving visual function. METHODS: A case report and literature review. RESULTS: A 54-year-old woman presented with a 3-day history of visual impairment, photophobia, and ocular pain in her right eye. Her best corrected visual acuity was 0.4 Logarithm of the Minimum Angle of Resolution scale, and the slit-lamp examination showed whitish corneal stromal infiltrate with satellite lesions. In vivo confocal microscopy evidenced Acanthamoeba cysts and fungal hyphae that resulted P. curvatum in the culture examination. The intensive medical treatment was started with topical 0.02% polyhexamethylene biguanide, voriconazole 1%, and moxifloxacin hydrochloride 0.5%. Progressive improvement of clinical and confocal pictures was registered with a complete recovery of visual function after 1 month. CONCLUSIONS: This is the first case report of combined P. curvatum and Acanthamoeba keratitis. The fast diagnosis with in vivo confocal microscopy allowed early and intensive specific treatment with recovery of corneal infection.


Assuntos
Ceratite por Acanthamoeba/diagnóstico , Ascomicetos/isolamento & purificação , Infecções Oculares Fúngicas/diagnóstico , Ceratite/diagnóstico , Micoses/diagnóstico , Ceratite por Acanthamoeba/tratamento farmacológico , Ceratite por Acanthamoeba/parasitologia , Administração Oftálmica , Antibacterianos/uso terapêutico , Antifúngicos/uso terapêutico , Biguanidas/uso terapêutico , Desinfetantes/uso terapêutico , Quimioterapia Combinada , Diagnóstico Precoce , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Feminino , Humanos , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Microscopia Confocal , Pessoa de Meia-Idade , Moxifloxacina/uso terapêutico , Micoses/tratamento farmacológico , Micoses/microbiologia , Soluções Oftálmicas , Microscopia com Lâmpada de Fenda , Voriconazol/uso terapêutico
16.
Fungal Biol ; 125(9): 718-724, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34420698

RESUMO

The Botryosphaeriaceae is a family of endophytic fungi, many of which are latent pathogens of woody plants. Although extensively sampled in some parts of the world, little is known regarding their occurrence across different environmental conditions. This study considered the presence of the Botryosphaeriaceae on Syzygium cordatum trees across a latitudinal gradient. We examined the relative importance of different environmental factors on the presence of the Botryosphaeriaceae across this latitudinal gradient. Specifically, Botryosphaeriaceae community composition and species richness were analysed. The optimal growth temperature of the most common Botryosphaeriaceae isolates and its relation to isolate origin was also tested in culture. We identified 14 Botryosphaeriaceae species including seven each of Lasiodiplodia and Neofusicoccum species. The maximum historical temperature emerged as the environmental factor that best predicted the presence of Botryosphaeriaceae species in S. cordatum trees, specifically influencing Botryosphaeriaceae community composition. For all the Botryosphaeriaceae species studied in vitro, temperature strongly influenced mycelial growth and they all had an optimal growth temperature of 25 °C. Contrary to our hypothesis, the optimal growth temperature was not related to isolate origin. These results contribute to understanding the presence of the Botryosphaeriaceae in trees and our ability to detect these latent pathogens.


Assuntos
Ascomicetos , Meio Ambiente , Syzygium , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Biodiversidade , Filogenia , Doenças das Plantas/microbiologia , África do Sul , Syzygium/microbiologia , Temperatura
17.
Microb Genom ; 7(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34424154

RESUMO

The activity of transposable elements (TEs) can be an important driver of genetic diversity with TE-mediated mutations having a wide range of fitness consequences. To avoid deleterious effects of TE activity, some fungi have evolved highly sophisticated genomic defences to reduce TE proliferation across the genome. Repeat-induced point mutation (RIP) is a fungal-specific TE defence mechanism efficiently targeting duplicated sequences. The rapid accumulation of RIPs is expected to deactivate TEs over the course of a few generations. The evolutionary dynamics of TEs at the population level in a species with highly repressive genome defences is poorly understood. Here, we analyse 366 whole-genome sequences of Parastagonospora nodorum, a fungal pathogen of wheat with efficient RIP. A global population genomics analysis revealed high levels of genetic diversity and signs of frequent sexual recombination. Contrary to expectations for a species with RIP, we identified recent TE activity in multiple populations. The TE composition and copy numbers showed little divergence among global populations regardless of the demographic history. Miniature inverted-repeat transposable elements (MITEs) and terminal repeat retrotransposons in miniature (TRIMs) were largely underlying recent intra-species TE expansions. We inferred RIP footprints in individual TE families and found that recently active, high-copy TEs have possibly evaded genomic defences. We find no evidence that recent positive selection acted on TE-mediated mutations rather that purifying selection maintained new TE insertions at low insertion frequencies in populations. Our findings highlight the complex evolutionary equilibria established by the joint action of TE activity, selection and genomic repression.


Assuntos
Elementos de DNA Transponíveis , Metagenômica , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Evolução Molecular , Variação Genética , Genoma , Genoma Fúngico , Genômica , Doenças das Plantas/microbiologia , Retroelementos
18.
PLoS One ; 16(8): e0253853, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34432788

RESUMO

Ophioceras is accommodated in the monotypic family Ophioceraceae (Magnaporthales, Sordariomycetes), and the genus is delimited based on molecular data. During an ongoing survey of bambusicolous fungi in southwest China, we collected a submerged decaying branch of bamboo from Sichuan Province, China and an Ophioceras species occurring on this substrate was observed and isolated. An Ophioceras taxon was delimited based on morphological characteristics and combined LSU, RPB1 and ITS sequence analyses and is described as Ophioceras sichuanense sp. nov. The species formed a well-supported clade basal to Ophioceras (100% ML, 1.00 PP). Based on the updated phylogenetic tree of Magnaporthales, Ceratosphaerella castillensis (generic type) and C. rhizomorpha formed a clade within Ophioceras and morphologically resemble Ophioceras. Therefore, Ceratosphaerella is synonymized under Ophioceras. The phylogenetic relationships of Ophioceras are discussed in relation to morphological similarities of genera in Magnaporthales. The generic circumscription of Ophioceras is emended.


Assuntos
Ascomicetos/classificação , Ascomicetos/genética , Filogenia , Ascomicetos/isolamento & purificação
19.
J Basic Microbiol ; 61(10): 923-939, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34374439

RESUMO

Pea (Pisum sativum L.) is of global importance as a food crop for its edible pod and seed. A new disease causing the tan to light brown blighted stems and pods has occurred in pea (P. sativum L.) plants in Chapainawabganj district, Bangladesh. A fungus with white-appressed mycelia and large sclerotia was consistently isolated from symptomatic tissues. The fungus formed funnel-shaped apothecia with sac-like ascus and endogenously formed ascospores. Healthy pea plants inoculated with the fungus produced typical white mold symptoms. The internal transcribed spacer sequences of the fungus were 100% similar to Sclerotinia sclerotiorum, considering the fungus to be the causative agent of white mold disease in pea, which was the first record in Bangladesh. Mycelial growth and sclerotial development of S. sclerotiorum were favored at 20°C and pH 5.0. Glucose was the best carbon source to support hyphal growth and sclerotia formation. Bavistin and Amistar Top inhibited the radial growth of the fungus completely at the lowest concentration. In planta, foliar application of Amistar Top showed the considerable potential to control the disease at 1.0% concentration until 7 days after spraying, while Bavistin prevented infection significantly until 15 days after spraying. A large majority (70.93%) of genotypes, including tested released pea cultivars, were susceptible, while six genotypes (6.98%) appeared resistant to the disease. These results on identification, characterization, host resistance, and fungicidal control of white mold could be valuable to achieve improved management of a new disease problem for pea cultivation.


Assuntos
Ascomicetos/patogenicidade , Doenças das Plantas/microbiologia , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/isolamento & purificação , Fungicidas Industriais/farmacologia , Genótipo , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Virulência
20.
Braz J Microbiol ; 52(4): 1791-1805, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34339015

RESUMO

Endophytes are regarded with immense potentials in terms of plant growth promoting (PGP) elicitors and mimicking secondary metabolites of medicinal importance. Here in the present study, we explored Bacopa monnieri plants to isolate, identify fungal endophytes with PGP elicitation potentials, and investigate secretion of secondary metabolites such as bacoside and withanolide content under in vitro conditions. Three fungal endophytes isolated (out of 40 saponin producing isolates) from leaves of B. monnieri were examined for in vitro biosynthesis of bacosides. On morphological, biochemical, and molecular identification (ITS gene sequencing), the isolated strains SUBL33, SUBL51, and SUBL206 were identified as Nigrospora oryzae (MH071153), Alternaria alternata (MH071155), and Aspergillus terreus (MH071154) respectively. Among these strains, SUBL33 produced highest quantity of Bacoside A3 (4093 µg mL-1), Jujubogenin isomer of Bacopasaponin C (65,339 µg mL-1), and Bacopasaponin C (1325 µg mL-1) while Bacopaside II (13,030 µg mL-1) was produced by SUBL51 maximally. Moreover, these aforementioned strains also produced detectable concentration of withanolides-Withaferrin A, Withanolide A (480 µg mL-1), and Withanolide B (1024 µg mL-1) respectively. However, Withanolide A was not detected in the secondary metabolites of strain SUBL51. To best of our knowledge, the present study is first reports of Nigrospora oryzae as an endophyte in B. monnieri with potentials of biosynthesis of economically important phytomolecules under in vitro conditions.


Assuntos
Bacopa , Endófitos , Fungos , Saponinas , Vitanolídeos , Alternaria/genética , Alternaria/isolamento & purificação , Alternaria/metabolismo , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Ascomicetos/metabolismo , Aspergillus/genética , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Bacopa/microbiologia , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Folhas de Planta/microbiologia , Saponinas/biossíntese , Vitanolídeos/metabolismo
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