Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.833
Filtrar
1.
BMC Plant Biol ; 22(1): 17, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34986803

RESUMO

BACKGROUND: The elemental defense hypothesis states a new defensive strategy that hyperaccumulators defense against herbivores or pathogens attacks by accumulating heavy metals. Brassica juncea has an excellent ability of cadmium (Cd) accumulation. However, the elemental defense effect and its regulation mechanism in B. juncea remain unclear. RESULTS: In this study, we profiled the elemental defense effect and the molecular regulatory mechanism in Cd-accumulated B. juncea after Alternaria brassicicola infection. B. juncea treated with 180 mg Kg- 1 DW CdCl2 2.5H2O exhibited obvious elemental defense effect after 72 h of infection with A. brassicicola. The expression of some defense-related genes including BjNPR1, BjPR12, BjPR2, and stress-related miRNAs (miR156, miR397, miR398a, miR398b/c, miR408, miR395a, miR395b, miR396a, and miR396b) were remarkably elevated during elemental defense in B. juncea. CONCLUSIONS: The results indicate that Cd-accumulated B. juncea may defend against pathogens by coordinating salicylic acid (SA) and jasmonic acid (JA) mediated systemic acquired resistance (SAR) and elemental defense in a synergistic joint effect. Furthermore, the expression of miRNAs related to heavy metal stress response and disease resistance may regulate the balance between pathogen defense and heavy metal stress-responsive in B. juncea. The findings provide experimental evidence for the elemental defense hypothesis in plants from the perspectives of phytohormones, defense-related genes, and miRNAs.


Assuntos
Alternaria/fisiologia , Cádmio/farmacologia , Mostardeira/imunologia , Doenças das Plantas/imunologia , Alternaria/efeitos dos fármacos , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , MicroRNAs/metabolismo , Anotação de Sequência Molecular , Mostardeira/efeitos dos fármacos , Mostardeira/genética , Mostardeira/microbiologia , Oxilipinas/metabolismo , Doenças das Plantas/microbiologia , Folhas de Planta , RNA de Plantas/metabolismo , Ácido Salicílico/metabolismo , Esporos Fúngicos/efeitos dos fármacos
2.
Microbiol Res ; 256: 126915, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34953292

RESUMO

The ability to cope with environmental abiotic stress and biotic stress is crucial for the survival of plants and microorganisms, which enable them to occupy multiple niches in the environment. Previous studies have shown that transcription factors play crucial roles in regulating various biological processes including multiple stress tolerance and response in eukaryotes. This work identified multiple critical transcription factor genes, metabolic pathways and gene ontology (GO) terms related to abiotic stress response were broadly activated by analyzing the transcriptome of phytopathogenic fungus Alternaria alternata under metal ions stresses, oxidative stress, salt stresses, and host-pathogen interaction. We investigated the biological functions and regulatory roles of the bZIP transcriptional factor (TF) genes in the phytopathogenic fungus A.alternata by analyzing targeted gene disrupted mutants. Morphological analysis provides evidence that the bZIP transcription factors (Gcn4, MeaB, Atf1, the ER stress regulator Hac1, and the all development altered-1 gene Ada1) are required for morphogenesis as the colony morphology of these gene deletion mutants was significantly different from that of the wild-type. In addition, bZIPs are involved in the resistance to multiple stresses such as oxidative stress (Ada1, Yap1, MetR) and virulence (Hac1, MetR, Yap1, Ada1) at varying degrees. Transcriptome data demonstrated that the inactivation of bZIPs (Hac1, Atf1, Ada1 and Yap1) significantly affected many genes in multiple critical metabolism pathways and gene ontology (GO) terms. Moreover,the ΔHac1 mutants displayed reduced aerial hypha and are hypersensitivity to endoplasmic reticulum disruptors such as tunicamycin and dithiothreitol. Transcriptome analysis showed that inactivation of Hac1 significantly affected the proteasome process and its downstream unfolded protein binding, indicating that Hac1 participates in the endoplasmic reticulum stress response through the conserved unfolded protein response. Taken together, our findings reveal that bZIP transcription factors function as key regulators of fungal morphogenesis, abiotic stress response and pathogenesis, and expand our understanding of how microbial pathogens utilize these genes to deal with environmental stresses and achieve successful infection in the host plant.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica , Fenômenos Biológicos , Alternaria , Fatores de Transcrição de Zíper de Leucina Básica/genética , Estresse Fisiológico
3.
Food Chem ; 368: 130858, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34425334

RESUMO

A modified quick, easy, cheap, effective, rugged, and safe extraction procedure combined with ultra-performance liquid chromatographic separation and ion mobility quadrupole time-of-flight mass spectrometry was developed to determine the presence of 20 mycotoxins (i.e., Alternaria toxins, ochratoxin, patulin, aflatoxin and trichothecenes) in fruit samples from Xinjiang. A complete platform, including screening via an in-house library, confirmation and quantification using reference standards, was established, which provided accurate MS data and complete spectra containing the fragment ions for each analyte. To evaluate the performance of the developed method, satisfactory validation parameters, such as linearity (R2 ≥ 0.9992), precision (RSDs ≤ 9.8%), recovery (81.2-99.2%), LOD (0.06-2.22 µg kg-1), and LOQ (0.2-7.39 µg kg-1), were obtained. The analysis of 130 fruit samples revealed nonnegligible contamination with mycotoxins; specifically, the highest levels of three Alternaria toxins were detected in jujube, wolfberries and raisins.


Assuntos
Micotoxinas , Alternaria , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Frutas/química , Micotoxinas/análise , Espectrometria de Massas em Tandem
4.
Food Chem ; 369: 130926, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34474284

RESUMO

Malting and brewing have previously been demonstrated to be risky procedures in terms of mycotoxins contamination. The goal of the study was to describe the fate of less investigated Fusarium and Alternaria mycotoxins, together with their conjugates, during these processes. The Pilsner malt producing process, together with double-mash brewing, were performed in a pilot-scale malting and brewery plants to simulate production of lager - the most popular type of central European beer. In addition, changes in temperature during barley germination were investigated to assess the influence of this critical step. QuEChERS-like extraction followed by UHPLC-HRMS/MS were utilized to quantify the mass balance of 13 mycotoxins and four of their conjugates. The results confirmed germination as the most determining malting step, followed by mashing of malt during brewing. Occurrence of type A trichothecenes, Alternaria mycotoxins and their conjugates in the final beer product indicates the need to take mitigation measures.


Assuntos
Fusarium , Micotoxinas , Alternaria , Cerveja/análise , Contaminação de Alimentos/análise , Micotoxinas/análise
5.
Talanta ; 237: 122917, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736653

RESUMO

The monitoring of the fungal genus Alternaria, which causes destructive brown spot disease in citruses worldwide and produces highly toxic mycotoxins, is extremely important to protect citrus and human health. In this work, we describe an ultrasensitive colorimetric method for the detection of genomic DNA of Alternaria from citrus fruit samples, using a system consisting of five groups of reporter probes. Each reporter probe is prepared by coupling recognition DNA and horseradish peroxidase (HRP) on the surface of gold nanoparticle (AuNP) through a convenient and low-cost freezing-assisted method. Meanwhile, the capture DNA is immobilized on magnetic bead (MB) via biotin-streptavidin reaction. Then, the capture DNA, target DNA, and five groups of AuNP-based reporter probes form a stable DNA-heptamer sandwich structure on the MB, and then HRP generates a blue signal for the subsequent colorimetric detection. It should be noted that AuNP with a large specific surface area drives abundant HRP anchoring, resulting in significant signal amplification. In addition, there are five groups of AuNP-based reporter probes, which further amplify the detection signal. As a result, the detection limit of the artificial target DNA is as low as 15.6 pM. Because the detection signal can be recorded visually without any special equipment, and its sensitivity is high, this method represents a suitable diagnostic tool for Alternaria genetic detection.


Assuntos
Técnicas Biossensoriais , Citrus , Nanopartículas Metálicas , Alternaria/genética , Colorimetria , DNA , Ouro , Peroxidase do Rábano Silvestre , Humanos , Limite de Detecção
6.
Exp Parasitol ; 230: 108176, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34740586

RESUMO

Foliar spray of silicon dioxide (SiO2 NPs), zinc oxide (ZnO NPs) and titanium dioxide (TiO2 NPs) nanoparticles were used for the management of Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani disease complex of carrot. Foliar spray of SiO2 NPs/ZnO NPs or TiO2 NPs increased plant growth attributes, chlorophyll and carotenoid of carrot. Foliar spray of 0.10 mg ml-1 SiO2 NPs caused the highest increase in plant growth, chlorophyll and carotenoid content of leaves followed by spray of 0.10 mg ml-1 ZnO NPs, 0.05 mg ml-1 SiO2 NPs, 0.05 mg ml-1 ZnO NPs, 0.10 mg ml-1 TiO2 NPs and 0.05 mg ml-1 TiO2 NPs. Use of SiO2 NPs caused a higher reduction in root galling, nematode multiplication and disease indices followed by ZnO NPs and TiO2 NPs. Two principal components analysis showed a total of 97.84% overall data variance in plants inoculated with single pathogen and 97.20% in plants inoculated with two or more pathogens. Therefore, foliar spray of SiO2 NPs appears interesting for the management of disease complex of carrot.


Assuntos
Alternaria/efeitos dos fármacos , Daucus carota , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Rhizoctonia/efeitos dos fármacos , Tylenchoidea/efeitos dos fármacos , Aerossóis , Alternaria/crescimento & desenvolvimento , Alternaria/patogenicidade , Animais , Carotenoides/análise , Clorofila/análise , Daucus carota/crescimento & desenvolvimento , Daucus carota/microbiologia , Daucus carota/parasitologia , Microscopia de Fluorescência , Nanopartículas/administração & dosagem , Folhas de Planta/química , Análise de Componente Principal , Rhizoctonia/crescimento & desenvolvimento , Rhizoctonia/patogenicidade , Dióxido de Silício/farmacologia , Titânio/farmacologia , Tylenchoidea/patogenicidade , Óxido de Zinco/farmacologia
7.
Appl Microbiol Biotechnol ; 105(23): 8869-8880, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34748037

RESUMO

Huperzine-A (HupA) is an emerging, powerful, and promising natural acetylcholinesterase inhibitor. Despite that, the achieved yields of HupA from microbial sources are still far from the industrial applications. Accordingly, this paper was conducted to valorize solid-state fermentation (SSF) as an efficient production platform of HupA. Four agro-industrial wastes, namely rice bran, potato peel, sugarcane bagasse, and wheat bran, were tested and screened as cultural substrates for the production of HupA by the endophytic Alternaria brassica under SSF. Maximum HupA production was attained on using rice bran moistened by Czapex's dox mineral broth. In the effort to increase the HupA titer, supplementation of the best moistening agent by different carbon and nitrogen sources was successfully investigated. Additionally, factors affecting HupA production under SSF including substrate concentration, moistening level, and inoculum concentration were optimized using response surface methodology. A Box-Behnken design was applied for generating a predictive model of the interactions between these factors. Under the optimum conditions of 15 g rice bran, inoculum concentration of 5 × 106 spores mL-1, and 60% moisture level, HupA concentration was intensified to 518.93 µg g-1. Besides, HupA production by the fungal strain was further enhanced using gamma-irradiation mutagenesis. The final HupA production was significantly intensified following exposure to 0.5 KGy gamma radiation to 1327 µg g-1, which represents a 12.85-fold increase. This is the first report on the successful production of the natural fungal metabolite HupA under SSF. Moreover, the achieved yield in this study using agro-industrial wastes may contribute to reducing the cost of HupA manufacture.Key points• Different agro-industrial by-products were tried as cultural substrates for the production of the acetylcholinesterase inhibitor HupA under SSF for the first time.• Factors affecting HupA production under SSF were optimized using response surface methodology.• The final HupA production was intensified following exposure to gamma radiation recording 1327 µg g-1, which represents a 12.85-fold increase.


Assuntos
Alternaria , Inibidores da Colinesterase , Acetilcolinesterase , Alcaloides , Fermentação , Raios gama , Sesquiterpenos
8.
J Phys Chem B ; 125(39): 10883-10892, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34546052

RESUMO

Living cells are neither perfectly elastic nor liquid and return a viscoelastic response to external stimuli. Nanoindentation provides force-distance curves, allowing the investigation of cell mechanical properties, and yet, these curves can differ from point to point on the cell surface, revealing its inhomogeneous character. In the present work, we propose a mathematical method to estimate both viscoelastic and noise properties of cells as these are depicted on the values of the scaling exponents of relaxation function and power spectral density, respectively. The method uses as input the time derivative of the response force in a nanoindentation experiment. Generalized moments method and/or rescaled range analysis is used to study the resulting time series depending on their nonstationary or stationary nature. We conducted experiments in living Ulocladium chartarum spores. We found that spores in the approaching phase present a viscoelastic behavior with the corresponding scaling exponent in the range 0.25-0.52 and in the retracting phase present a liquid-like behavior with exponents in the range 0.67-0.85. This substantial difference of the scaling exponents in the two phases suggests the formation of biomemory as a response of the spores to the indenting AFM mechanical stimulus. The retracting phase may be described as a process driven by bluish noises, while the approaching one is driven by persistent noise.


Assuntos
Elasticidade , Alternaria , Microscopia de Força Atômica , Viscosidade
9.
Arch Microbiol ; 203(10): 5975-5992, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34535810

RESUMO

Airborne fungi are one of the major components of aeromycobiota known to produce several fungal diseases in fruits. Their presence in indoor environment of warehouses may limit the storage period of apples. Qualitative and quantitative analyses of airborne fungal spores were conducted using gravity settling techniques to detect fungal airspora present in the atmosphere of two apple warehouses in Tunisia. In this study, 375 fungal isolates were obtained and purified. Phylogenetic analysis of calmodulin, beta-tubulin and ITS regions coupled with phenotypic characterization helped to identify 15 fungal species. Penicillium exhibited the highest diversity with ten species detected (Penicillium allii, P. chrysogenum, P. citrinum, P. expansum, P. italicum, P. polonicum, P. solitum, P. steckii, P. sumatraense and P. viridicatum), followed by four species of Aspergillus genus (Aspergillus europaeus, A. flavus, A. niger and A. pulverulentus) and Alternaria alternata. In vivo experiments confirmed the pathogenicity of 13 species at room temperature and under cold-storage conditions. Among them, A. europaeus, A. pulverulentus, P. allii and P. sumatraense were described for the first time as pathogens on apples. The present study identified the major airborne fungi associated with postharvest rot in apple storage facilities in Tunisia and may help in efficient control of postharvest and storage fruit diseases.


Assuntos
Poluição do Ar , Malus , Penicillium , Alternaria , Aspergillus/genética , Penicillium/genética , Filogenia
10.
Front Immunol ; 12: 677848, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34484177

RESUMO

Future precision medicine requires further clarifying the mechanisms of inflammation in the severe endotypes of chronic airway diseases such as asthma and chronic rhinosinusitis (CRS). The presence of neutrophils in the airways is often associated with severe airway inflammation, while their precise contribution to the severe inflammation is largely unknown. We aimed to study the role of neutrophils in BALB/c and C57BL/6 mice exposed to Alternaria alternata (Alt). The mice were exposed to Alt extract for twelve hours or ten days to induce allergic airway inflammation. C57BL/6 mice exposed to Alt responded with eosinophilic infiltration and the characteristic IL-5 upregulation. In contrast, the inflammatory response to Alt extract in BALB/c mice was characterized by a neutrophilic response, high levels of G-CSF, and elastase in the lungs. The lack of neutrophils affected the processing of IL-33 in BALB/c mice, as was demonstrated by depletion of neutrophils through intraperitoneal injections of anti-Ly6G antibody. Our data identifies the key role of neutrophils in airway inflammation through IL-33 cleavage in the Alt-induced airway inflammation in mice, which could potentially underline the different endotypes in human disease.


Assuntos
Alérgenos/imunologia , Alternaria/imunologia , Alternariose/imunologia , Asma/imunologia , Imunidade Inata , Interleucina-33/metabolismo , Neutrófilos/imunologia , Rinite/imunologia , Sinusite/imunologia , Alternariose/microbiologia , Animais , Asma/microbiologia , Modelos Animais de Doenças , Feminino , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Rinite/microbiologia , Sinusite/microbiologia
11.
Front Cell Infect Microbiol ; 11: 683194, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34485171

RESUMO

Alternaria alternata is a ubiquitous fungus and a major allergen associated with the development of asthma. Inhalation of intact spores is the primary cause of human exposure to fungal allergen. However, allergen-rich cultured fungal filtrates are oftentimes used in the current models of fungal sensitization that do not fully reflect real-life exposures. Thus, establishing novel spore exposure models is imperative. In this study, we established novel fungal exposure models of both adult and neonate to live spores. We examined pathophysiological changes in the spore models as compared to the non-exposure controls and also to the conventional filtrate models. While both Alternaria filtrate- and spore-exposed adult BALB/c mice developed elevated airway hyperresponsiveness (AHR), filtrates induced a greater IgE mediated response and higher broncholavage eosinophils than spores. In contrast, the mice exposed to Alternaria spores had higher numbers of neutrophils. Both exposures induced comparable levels of lung tissue inflammation and mucous cell metaplasia (MCM). In the neonatal model, exposure to Alternaria spores resulted in a significant increase of AHR in both adult and neonatal mice. Increased levels of IgE in both neonatal and adult mice exposed to spores was associated with increased eosinophilia in the treatment groups. Adult demonstrated increased numbers of lymphocytes that was paralleled by increased IgG1 production. Both adults and neonates demonstrated similarly increased eosinophilia, IgE, tissue inflammation and MCM.


Assuntos
Asma , Alérgenos , Alternaria , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos BALB C , Esporos Fúngicos
12.
Int J Food Microbiol ; 357: 109367, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34482184

RESUMO

Alternaria is one of the main fungal genera affecting the quality of barley grains. In this study, a polyphasic approach was carried out to characterise the Alternaria population infecting different cultivars of barley grains from the major producing regions of Argentina in the 2014 and 2015 seasons. Its relationship with Fusarium and correlations between predominant species, barley cultivars, and climatic conditions in the growing regions were evaluated. Alternaria incidence exceeded that of Fusarium in all the barley samples and was higher in the drier season (21% in 2014 and 42% in 2015 vs. 6% and 4%, respectively). The main Alternaria species-groups identified were present in both growing seasons in similar frequencies (A. tenuissima sp.-grp., 83.4% in 2014 and 81.7% in 2015; A. infectoria sp.-grp., 11.7% in 2014 and 11.3% in 2015). The dominant Alternaria species-group isolated and identified based on morphological characteristics, DNA sequencing, and metabolite profile was A. tenuissima (72.9%), followed by A. infectoria (14.6%). An association between their frequency and field temperature was observed; A. tenuissima sp.-grp. was more frequent in northern localities, where higher temperatures were registered, while the opposite was observed for A. infectoria sp.-grp. A smaller percentage of A. arborescens sp.-grp. (5%), A. alternata sp.-grp. (3.9%) and A. vaccinii (1.4%) were also identified. Both secondary metabolite profiles and phylogenetic analysis were useful to distinguish isolates from Alternaria section Alternaria and section Infectoriae. Regarding metabolite profiles, alternariol was the most frequent compound produced by isolates of the section Alternaria. Infectopyrones and novae-zelandins were produced by most of the isolates from section Infectoriae. The barley cultivars analysed in this study did not show a particular susceptibility regarding the Alternaria population composition, except for Andreia, which presented the highest frequency of contamination with A. tenuissima sp.-grp. The rest of the cultivars, when grown in different regions, showed different proportion of the Alternaria sp.-grps., suggesting that other factors were determinant in their distribution. The results obtained in the present study will be a valuable tool for health authorities to assess the need for regulations on Alternaria mycotoxins, given the high incidence of Alternaria spp. in barley and the diversity of metabolites that might contaminate the grains.


Assuntos
Fusarium , Hordeum , Micotoxinas , Alternaria , Filogenia
13.
Bioorg Chem ; 116: 105309, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34479054

RESUMO

Six new polyketone metabolites, compounds (1-6) and seven known polyketone compounds (7-13) were isolated from Rhodiola tibetica endophytic fungus Alternaria sp. The structural elucidation of five new polyketone metabolites were elucidated on the basis of spectroscopic including 2D NMR and HRMS and spectrometric analysis. Inhibition rate evaluation revealed that compounds 1(EC50 = 0.02 mM), 3(EC50 = 0.3 mM), 6(EC50 = 0.07 mM), 8(EC50 = 0.1 mM) and 9(EC50 = 0.04 mM) had inhibitory effect on the SARS-CoV-2 virus.


Assuntos
Alternaria/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Cetonas/isolamento & purificação , Cetonas/farmacologia , Polímeros/isolamento & purificação , Polímeros/farmacologia , SARS-CoV-2/efeitos dos fármacos , Antivirais/química , Humanos , Cetonas/química , Estrutura Molecular , Polímeros/química
14.
Chin J Nat Med ; 19(9): 700-705, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34561082

RESUMO

Biotransformation of α-asarone by Alternaria longipes CGMCC 3.2875 yielded two pairs of new neolignans, (+) (7S, 8S, 7'S, 8'R) iso-magnosalicin (1a)/(-) (7R, 8R, 7'R, 8'S) iso-magnosalicin (1b) and (+) (7R, 8R, 7'S, 8'R) magnosalicin (2a)/(-) (7S, 8S, 7'R, 8'S) magnosalicin (2b), and four known metabolites, (±) acoraminol A (3), (±) acoraminol B (4), asaraldehyde (5), and 2, 4, 5-trimethoxybenzoic acid (6). Their structures, including absolute configurations, were determined by extensive analysis of NMR spectra, X-ray crystallography, and quantum chemical ECD calculations. The cytotoxic activity and Aß42 aggregation inhibitory activity of all the compounds were evaluated. Compound 2 displayed significant anti-Aß42 aggregation activity with an inhibitory rate of 60.81% (the positive control EGCG: 69.17%). In addition, the biotransformation pathway of α-asarone by Alternaria longipes CGMCC 3.2875 was proposed.


Assuntos
Alternaria , Lignanas , Derivados de Alilbenzenos , Anisóis , Biotransformação , Estrutura Molecular
15.
Artigo em Inglês | MEDLINE | ID: mdl-34574831

RESUMO

Monitoring the indoor microclimate in old buildings of cultural heritage and significance is a practice of great importance because of the importance of their identity for local communities and national consciousness. Most aged heritage buildings, especially those made of wood, develop an indoor microclimate conducive to the development of microorganisms. This study aims to analyze one wooden church dating back to the 1710s in Romania from the microclimatic perspective, i.e., temperature and relative humidity and the fungal load of the air and surfaces. One further aim was to determine if the internal microclimate of the monument is favorable for the health of parishioners and visitors, as well as for the integrity of the church itself. The research methodology involved monitoring of the microclimate for a period of nine weeks (November 2020-January 2021) and evaluating the fungal load in indoor air as well as on the surfaces. The results show a very high contamination of air and surfaces (>2000 CFU/m3). In terms of fungal contamination, Aspergillus spp. (two different species), Alternaria spp., Cladosporium spp., Mucor spp., Penicillium spp. (two different species) and Trichopyton spp. were the genera of fungi identified in the indoor wooden church air and Aspergillus spp., Cladosporium spp., Penicillium spp. (two different species) and Botrytis spp. on the surfaces (church walls and iconostasis). The results obtained reveal that the internal microclimate not only imposes a potential risk factor for the parishioners and visitors, but also for the preservation of the wooden church as a historical monument, which is facing a crisis of biodeterioration of its artwork.


Assuntos
Poluição do Ar em Ambientes Fechados , Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Alternaria , Monitoramento Ambiental , Fungos , Romênia
16.
Mycologia ; 113(5): 1073-1088, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34338599

RESUMO

In this study, the diversity of Alternaria species in section Nimbya associated with symptomatic plants in the Cyperaceae and Juncaceae families was assessed. Multilocus sequence analyses of the rDNA internal transcribed spacer (ITS) region and parts of Alternaria major allergen (Alt a 1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), second largest subunit of RNA polymerase II (RPB2), and translation elongation factor 1-alpha (TEF1) genes revealed the presence of two previously known species, A. scirpivora and A. caricicola, and three new species, which are described here as A. cypericola, sp. nov., A. heyranica, sp. nov., and A. junci-acuti, sp. nov. These new species were characterized morphologically with respect to the dimensions of conidia, the number of pseudosepta in mature conidia, and the type of conidium apical beak. According to the results of phylogenetic analyses, the presence of long, filiform true beak is not a reliable morphological indicator for grouping species in sections Alternantherae and Nimbya and phylogenetic species recognition should be used. All identified species were described, illustrated, and their morphology and phylogenetic relationships with other species in Alternaria section Nimbya were discussed.


Assuntos
Alternaria , Alternaria/genética , Humanos , Irã (Geográfico) , Tipagem de Sequências Multilocus , Filogenia , Análise de Sequência de DNA
17.
Arch Microbiol ; 203(8): 5173-5182, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34338823

RESUMO

Endophytes associated with plants have the property to produce active biomolecules with their possible applications in agro-industrial sectors. This study provides a project work on analyzing various activities of fungal endophytes isolated from Swertia chirayita of Sikkim Himalayan region. Among several fungal endophytes screened, isolate UTCRF6 was found most active with the secretion of enzymes protease, cellulase, amylase and chitinase, as well as other metabolites Indoleacetic acid and siderophores. This endophyte was found active in restricting the growth of phyto-pathogens, including strains of Fusarium solani, Colletotrichum gloeosporioides, Alternaria alternata, Pestalotiopsis theae and Sclerotinia sclerotiorum. Morphological and molecular studies of this endophytic fungus showed similarity with Penicillium citrinum.


Assuntos
Ascomicetos , Agentes de Controle Biológico , Penicillium , Plantas Medicinais , Swertia , Alternaria/patogenicidade , Ascomicetos/patogenicidade , Colletotrichum/patogenicidade , Endófitos , Fusarium/patogenicidade , Plantas Medicinais/microbiologia , Swertia/microbiologia
18.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445145

RESUMO

The main goal of growing plants under various photoperiods is to optimize photosynthesis for using the effect of day length that often acts on plants in combination with biotic and/or abiotic stresses. In this study, Brassica juncea plants were grown under four different day-length regimes, namely., 8 h day/16 h night, 12 h day/12 h night, 16 h day/8 h night, and continuous light, and were infected with a necrotrophic fungus Alternaria brassicicola. The development of necroses on B. juncea leaves was strongly influenced by leaf position and day length. The largest necroses were formed on plants grown under a 16 h day/8 h night photoperiod at 72 h post-inoculation (hpi). The implemented day-length regimes had a great impact on leaf morphology in response to A. brassicicola infection. They also influenced the chlorophyll and carotenoid contents and photosynthesis efficiency. Both the 1st (the oldest) and 3rd infected leaves showed significantly higher minimal fluorescence (F0) compared to the control leaves. Significantly lower values of other investigated chlorophyll a fluorescence parameters, e.g., maximum quantum yield of photosystem II (Fv/Fm) and non-photochemical quenching (NPQ), were observed in both infected leaves compared to the control, especially at 72 hpi. The oldest infected leaf, of approximately 30% of the B. juncea plants, grown under long-day and continuous light conditions showed a 'green island' phenotype in the form of a green ring surrounding an area of necrosis at 48 hpi. This phenomenon was also reflected in changes in the chloroplast's ultrastructure and accelerated senescence (yellowing) in the form of expanding chlorosis. Further research should investigate the mechanism and physiological aspects of 'green islands' formation in this pathosystem.


Assuntos
Alternaria/patogenicidade , Mostardeira/microbiologia , Mostardeira/fisiologia , Necrose/microbiologia , Necrose/patologia , Fotossíntese/fisiologia , Doenças das Plantas/microbiologia , Carotenoides/metabolismo , Clorofila/metabolismo , Clorofila A/metabolismo , Fluorescência , Mostardeira/metabolismo , Necrose/metabolismo , Fotoperíodo , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia
19.
Phytochemistry ; 191: 112921, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34425462

RESUMO

Three previously undescribed metabolites named argyrotoxins A-C, were isolated, together with the well known porritoxinol, its closely related phthalide, a phthalide derivative, zinniol, alternariol and its 4-methyl ether from Alternaria argyroxiphii E.G. Simmons & Aragaki, the causal agent of leaf spot on African mahogany trees, Khaya senegalensis A. Juss. (Meliaceae). The known compounds were identified comparing their physical and spectroscopic properties to those previously reported in literature. Argyrotoxins A-C were characterized essentially by NMR (1H, 13C, COSY, HSQC, HMBC and NOESY NMR spectra) and HRESIMS spectra as 4-(7-methoxy-6-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yloxy)-2-methyl-butyric acid, 5-but-2-enyloxy-N-(2-hydroxyethyl)-2-hydroxymethyl-3-methoxy-4-methyl-benzamide and 1-(5-(hydroxymethyl)-3-methoxy-4-(methoxymethyl)-2-methylphenoxy)-3-methylbutane-2,3-diol, respectively. The absolute configuration of argyrotoxin A was determined through electronic circular dichroism, by applying the biphenyl chiroptical probe approach. The phytoxicity of all metabolites isolated was evaluated by leaf puncture assay at concentration of 1 mg/mL. Zinniol proved to be the most active compound causing necrotic lesions on young leaves of Hedera elix L., Phaseolus vulgaris L. and Quercus ilex L. Argirotoxins A and B were found active, to a minor extent, on Phaseolus vulgaris L. leaves, while porritoxinol exhibited activity on holm oak leaves. The other secondary metabolites herein reported for A. argyroxiphii were inactive.


Assuntos
Alternaria , Meliaceae , Éter , Éteres , Árvores
20.
Sci Rep ; 11(1): 17024, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34426589

RESUMO

Early blight (EB) caused by Alternaria linariae or Alternaria solani and leaf blight (LB) caused by A. alternata are economically important diseases of tomato and potato. Little is known about the genetic diversity and population structure of these pathogens in the United States. A total of 214 isolates of A. alternata (n = 61), A. linariae (n = 96), and A. solani (n = 57) were collected from tomato and potato in North Carolina and Wisconsin and grouped into populations based on geographic locations and tomato varieties. We exploited 220 single nucleotide polymorphisms derived from DNA sequences of 10 microsatellite loci to analyse the population genetic structure between species and between populations within species and infer the mode of reproduction. High genetic variation and genotypic diversity were observed in all the populations analysed. The null hypothesis of the clonality test based on the index of association [Formula: see text] was rejected, and equal frequencies of mating types under random mating were detected in some studied populations of Alternaria spp., suggesting that recombination can play an important role in the evolution of these pathogens. Most genetic differences were found between species, and the results showed three distinct genetic clusters corresponding to the three Alternaria spp. We found no evidence for clustering of geographic location populations or tomato variety populations. Analyses of molecular variance revealed high (> 85%) genetic variation within individuals in a population, confirming a lack of population subdivision within species. Alternaria linariae populations harboured more multilocus genotypes (MLGs) than A. alternata and A. solani populations and shared the same MLG between populations within a species, which was suggestive of gene flow and population expansion. Although both A. linariae and A. solani can cause EB on tomatoes and potatoes, these two species are genetically differentiated. Our results provide new insights into the evolution and structure of Alternaria spp. and can lead to new directions in optimizing management strategies to mitigate the impact of these pathogens on tomato and potato production in North Carolina and Wisconsin.


Assuntos
Alternaria/genética , Variação Genética , Lycopersicon esculentum/microbiologia , Solanum tuberosum/microbiologia , Sequência de Bases , Análise Discriminante , Genes Fúngicos Tipo Acasalamento , Genótipo , Geografia , Desequilíbrio de Ligação/genética , Repetições de Microssatélites/genética , North Carolina , Nucleotídeos/genética , Polimorfismo de Nucleotídeo Único/genética , Análise de Componente Principal , Probabilidade , Wisconsin
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...