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1.
Food Chem ; 400: 134016, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084588

RESUMO

This work aims to investigate antifungal, mycotoxin inhibitory efficacy of the hop essential oil (HEO) nanoemulsion and their mode of action (MOA) against Fusarium graminearum isolate, a fungal pathogen causing Fusarium Head Blight (FHB) in cereal crops. The HEO, primarily consisting of terpenes and terpenoids, was encapsulated in nanoemulsion droplets. Physically stable HEO-in-water nanoemulsion was fabricated using 0.5 wt% of tween 80 and 5 wt% oil phase comprising 30 % of Ostwald ripening inhibitor and 70 % of HEO. In terms of antifungal effect, HEO nanoemulsion could not only effectively inhibit mycelial growth and spore germination of F. graminearum isolates, but also remarkably suppress the production of deoxynivalenol (DON) and its derivatives in rice culture by applying 750 µg of HEO/g rice. Our studies on the MOA showed that HEO nanoemulsion could alter the contents of total lipid and chitin in outer cell membrane as well as damaging cytoplasmic membrane.


Assuntos
Fusarium , Micotoxinas , Óleos Voláteis , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Quitina/metabolismo , Fusarium/metabolismo , Micotoxinas/metabolismo , Óleos Voláteis/metabolismo , Óleos Voláteis/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Polissorbatos/farmacologia , Terpenos/metabolismo , Água/metabolismo
2.
Braz. j. biol ; 83: e246230, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339369

RESUMO

Abstract Dengue fever vectored by the mosquito Aedes aegypti is one of the most rapidly spreading insect-borne diseases. Current reliance of dengue vector control is mostly on chemical insecticides. Growing insecticide resistance in the primary mosquito vector, Aedes aegypti, limits the effectiveness of vector control through chemical insecticides. These chemical insecticides also have negative environmental impacts on animals, plants and human health. Myco-biocontrol agents are naturally occurring organisms and are found to be less damaging to the environment as compared to chemical insecticides. In the present study, entomopathogenic potential of local strains of fungi isolated from soil was assessed for the control of dengue vector. Local fungal isolates presents better alternative to introducing a foreign biocontrol strain, as they may be better adapted to environmental conditions of the area to survive and may have more entomopathogenic efficacy against target organism. Larvicidal efficacy of Fusarium equiseti and Fusarium proliferatum was evaluated against Aedes aegypti. Local strains of F. equiseti (MK371718) and F. proliferatum (MK371715) were isolated from the soil of Changa Manga Forest, Pakistan by using insect bait method. Larvicidal activity of two Fusarium spp. was tested against forth instar larvae of A. aegypti in the laboratory, using concentrations 105, 106, 107 and 108 conidia /ml. LC50 values for F. equiseti after 24h, 48h, 72h and 96h of exposure were recorded as 3.8x 108, 2.9x107, 2.0x107, and 7.1x106 conidia /ml respectively while LC50 values for F. proliferatum were recorded as 1.21x108, 9.6x107, 4.2x107, 2.6x107 conidia /ml respectively after 24h, 48h, 72h and 96h of exposure. The results indicate that among two fungal strains F. equiseti was found to be more effective in terms of its larvicidal activity than F. proliferatum against larvae of A. aegypti.


Resumo A dengue transmitida pelo mosquito Aedes aegypti é uma das doenças transmitidas por insetos de propagação mais rápida. A dependência atual do controle do vetor da dengue é principalmente de inseticidas químicos. O aumento da resistência a inseticidas no principal vetor do mosquito, Aedes aegypti, limita a eficácia do controle do vetor por meio de inseticidas químicos. Esses inseticidas químicos também têm impactos ambientais negativos sobre os animais, plantas e saúde humana. Os agentes de micobiocontrole são organismos que ocorrem naturalmente e são menos prejudiciais ao meio ambiente em comparação com os inseticidas químicos. No presente estudo, avaliou-se o potencial entomopatogênico de cepas locais de fungos isolados do solo para o controle do vetor da dengue. Isolados de fungos locais apresentam melhor alternativa para a introdução de uma cepa de biocontrole estrangeira, pois podem ser mais bem adaptados às condições ambientais da área para sobreviver e podem ter maior eficácia entomopatogênica contra o organismo-alvo. A eficácia larvicida de Fusarium equiseti e Fusarium proliferatum foi avaliada contra Aedes aegypti. Cepas locais de F. equiseti (MK371718) e F. proliferatum (MK371715) foram isoladas do solo de Changa Manga Forest, Paquistão, usando o método de isca para insetos. Atividade larvicida de dois Fusarium spp. foi testado contra larvas de quarto ínstar de A. aegypti em laboratório, nas concentrações 105, 106, 107 e 108 conídios / ml. Os valores de LC50 para F. equiseti após 24 h, 48 h, 72 h e 96 h de exposição foram registrados como 3,8x 108, 2,9x107, 2,0x107 e 7,1x106 conídios / ml, respectivamente, enquanto os valores de LC50 para F. proliferatum foram registrados como 1,21x108, 9,6 x107, 4,2x107, 2,6x107 conídios / ml, respectivamente, após 24 h, 48 h, 72 h e 96 h de exposição. Os resultados indicam que entre duas cepas de fungos F. equiseti se mostrou mais eficaz em termos de atividade larvicida do que F. proliferatum contra larvas de A. aegypti.


Assuntos
Humanos , Animais , Aedes , Fusarium , Inseticidas/farmacologia , Paquistão , Solo , Extratos Vegetais , Florestas , Mosquitos Vetores , Larva
3.
Braz. j. biol ; 83: e244261, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285633

RESUMO

Abstract Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.


Resumo As bactérias endofíticas desempenham papel fundamental na manutenção da saúde e do crescimento das plantas. Poucos estudos até o momento, no entanto, exploraram as propriedades antagônicas e promotoras de crescimento de plantas (PGP) de endófitos de Prunus cerasifera. Para esse fim, isolamos bactérias endofíticas de amostras de tecido de P. cerasifera e usamos um ensaio de placa de cultura dupla para rastrear esses micróbios quanto à atividade antagonista contra Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum e F. moniliforme. Das 36 cepas de bactérias isoladas, quatro (cepas P1, P10, P16 e P20) exibiram efeitos antagônicos contra todos os cinco patógenos modelo, e a cepa P10 exibiu o antagonista mais forte para cinco patógenos. Essa cepa P10 foi então caracterizada em profundidade por meio de avaliações fenotípicas, análises fisiológicas e sequenciamento de rDNA 16s, revelando ser uma cepa de Bacillus subtilis. A aplicação de uma suspensão de células P10 (1 × 108 UFC / mL) aumentou significativamente a germinação das sementes e o crescimento das mudas de tomate em casa de vegetação. Essa cepa P10 suprimiu ainda mais a murcha de Verticillium do tomate com incidência de doença muito menor e pontuações de índice de doença sendo observadas após o tratamento com P10 em relação a plantas não tratadas em experimentos baseados em vasos. As plantas de tomate que foram tratadas com a cepa P10 também aumentaram as enzimas relacionadas à defesa, peroxidase, superóxido dismutase e atividade da catalase após o desafio de V. dahliae em relação às plantas que não foram tratadas com essa bactéria endofítica. Os resultados revelaram que a cepa bacteriana P10 tem valor potencial como agente de biocontrole para uso na prevenção da murcha de Verticillium em tomate.


Assuntos
Lycopersicon esculentum , Verticillium , Prunus domestica , Doenças das Plantas/prevenção & controle , Ascomicetos , Bacillus subtilis , Fusarium
4.
Microbes Environ ; 37(4)2022.
Artigo em Inglês | MEDLINE | ID: mdl-36184470

RESUMO

An evaluation of suppressiveness against soil-borne diseases is important for their control. We herein assessed disease suppression against F. oxysporum f. sp. spinaciae using the Fusarium co-cultivation method in 75 soils collected from croplands around the country. The suppressive effects of soil microbes against F. oxysporum growth were examined by simultaneously culturing soil suspensions and F. oxysporum f. sp. spinaciae on a culture medium. The growth degree of F. oxysporum on the medium varied among the 75 soils tested, and 14 soils showing different degrees of growth were selected to investigate the incidence of spinach wilt by cultivating spinach inoculated with the pathogenic F. oxysporum strain. A correlation (r=0.831, P<0.001) was observed between the disease incidence of spinach wilt and the growth degree of F. oxysporum using the co-cultivation method in the 14 selected soils. No correlations were noted between chemical and biological parameters (including pH and the population density of microbes, except for the growth degree of F. oxysporum) and the growth degree of F. oxysporum and incidence of spinach wilt, indicating that it was not possible to predict the degree of growth or disease incidence based on specific chemical and biological characteristics or their combination. The present results suggest that an evaluation of the growth degree of F. oxysporum by the Fusarium co-cultivation will be useful for diagnosing the disease suppressiveness of soil against pathogenic F. oxysporum in croplands.


Assuntos
Fusarium , Produtos Agrícolas , Doenças das Plantas/prevenção & controle , Solo/química , Microbiologia do Solo , Spinacia oleracea
5.
Biomed Res Int ; 2022: 5960004, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36060140

RESUMO

Microbial inoculants are an important tool for increasing arable land productivity and decreasing mineral fertilizer application. This study was aimed at isolating and identifying endophytic antagonistic bacteria from lily (Lilium davidii var. unicolor) roots grown in Northwestern China and at evaluating their antifungal activity and plant growth-promoting characteristics. For this purpose, endophytic bacteria were isolated from plant roots, and plant growth-promoting strains were identified. One bacterial strain, isolated from the root part, was identified as Bacillus halotolerans based on 16S rRNA gene sequence analysis and was designated as LBG-1-13. The strain showed antagonistic activities against important plant pathogens of lily including Botrytis cinerea, Botryosphaeria dothidea, and Fusarium oxysporum. The highest percentage of growth inhibition, i.e., 71.65 ± 2.39%, was observed for LBG-1-13 against Botryosphaeria dothidea followed by 68.33 ± 4.70% and 48.22 ± 4.11% against Botrytis cinerea and Fusarium oxysporum, respectively. Meanwhile, the isolated strain also showed plant growth-promoting traits such as the production of indole-3-acetic acid (IAA), siderophore, ACC deaminase, and phosphate solubilization activity. The strain showed ACC deaminase activity and was able to cleave 58.41 ± 2.62 nmol α-ketobutyrate (mg protein)-1 min-1. The strain exhibited tolerance to salt and drought stress in an in vitro experiment. The strain LBG-1-13 was able to grow in the presence of 10% NaCl and 20% polyethylene glycol (PEG) in the growth medium. Inoculation of Lilium varieties, Tresor and Bright Diamond, with LBG-1-13 enhanced plant growth under greenhouse and field conditions, respectively. All these results demonstrated that Bacillus halotolerans LBG-1-13 could be utilized as a good candidate in the biocontrol of lily disease and plant growth promotion in sustainable agriculture.


Assuntos
Lilium , Ascomicetos , Bacillus , Bactérias/genética , Botrytis , Fusarium , RNA Ribossômico 16S/genética
6.
PLoS One ; 17(9): e0273335, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36129882

RESUMO

In the last century, Fusarium wilt of banana (FWB) destroyed the banana cultivar Gros Michel. The Cavendish cultivars saved the global banana industry, and currently they dominate global production (~50%) and the export trade (~95%). However, a new strain called Tropical Race 4 (TR4) surfaced in the late 1960's, spread globally and greatly damages Cavendish plantations as well as manifold local varieties that are primarily grown by small holders. Presently, there is no commercially available replacement for Cavendish and hence control strategies must be developed and implemented to manage FWB. Here, we studied whether it is possible to induce resistance to TR4 by pre-inoculations with different Fusarium spp. Only pre-treatments with an avirulent Race 1 strain significantly reduced disease development of TR4 in a Cavendish genotype and this effect was stable at various nutritional and pH conditions. We then used transcriptome analysis to study the molecular basis of this response. Several genes involved in plant defence responses were up-regulated during the initial stages of individual infections with TR4 and Race 1, as well as in combined treatments. In addition, a number of genes in the ethylene and jasmonate response pathways as well as several gibberellin synthesis associated genes were induced. We observed upregulation of RGA2 like genes in all treatments. Hence, RGA2 could be a key factor involved in both R1 and TR4 resistance. The data support the hypothesis that activating resistance to Race 1 in Cavendish bananas affects TR4 development and provide a first insight of gene expression during the interaction between various Fusarium spp. and banana.


Assuntos
Fusarium , Musa , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Musa/genética , Musa/metabolismo , Doenças das Plantas/genética
7.
Invest Ophthalmol Vis Sci ; 63(10): 20, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36169946

RESUMO

Purpose: Our previous investigations revealed a significant role of methyltransferase-like 3 (METTL3)-mediated N6-methyladenosine (m6A) modification in the development of corneal inflammation in Fusarium infection, but the exact mechanism is unknown. Therefore, this research aimed to explore how METTL3 affects the inflammatory process of fungal keratitis (FK) in mice. Methods: We established in vitro and in vivo models by inoculating mice and primary corneal stromal cells with F. solani. METTL3 expression was confirmed by real-time quantitative polymerase chain reaction, immunofluorescence, and western blotting. After that, siRNAMETTL3 and AAV-sh-METTL3 were transfected into cells and mice to explore the role of METTL3 in the PI3K/AKT signaling pathway and inflammation. PI3K, p-PI3K, AKT, and p-AKT expression was analyzed by western blotting. Viability of corneal stromal cells was measured using a Cell Counting Kit-8 (CCK-8). Additionally, we detected interleukin (IL)-6, IL-1ß, and tumor necrosis factor alpha (TNF-α) levels in corneal tissues and analyzed the role of METTL3 in inflammation in FK using slit-lamp biomicroscopy and hematoxylin and eosin staining. Results: Here, our results show that METTL3 increased in mouse FK, and the expression of p-PI3K and p-AKT decreased when METTL3 was downregulated. We also found that knockdown of METTL3 expression attenuated the inflammatory response and decreased TNF-α, IL-1ß, and IL-6 expression in corneal-infected mice. Furthermore, inhibition of the PI3K/AKT pathway attenuated the inflammatory response of FK, decreased the expression of the above inflammatory factors, and enhanced the viability of corneal stromal cells. Conclusions: Based on the study results, METTL3 downregulation attenuates Fusarium-induced corneal inflammation via the PI3K/AKT signaling pathway.


Assuntos
Infecções Oculares Fúngicas , Fusarium , Ceratite , Animais , Amarelo de Eosina-(YS) , Infecções Oculares Fúngicas/metabolismo , Hematoxilina , Inflamação/metabolismo , Interleucina-6/metabolismo , Ceratite/microbiologia , Metiltransferases/genética , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Sincalida , Fator de Necrose Tumoral alfa/metabolismo
8.
BMC Microbiol ; 22(1): 229, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36175855

RESUMO

Fusarium root rot, caused by Fusarium solani (Mart.) Sacc., represents one of the most damaging diseases of maize affecting plant growth and yield. In this study, the antagonistic potential of a non-aflatoxigenic endophytic Aspergillus flavus YRB2, isolated from Thymelaea hirsuta (L.) Endl., was tested against F. solani in vitro. In addition, its biocontrol activity against Fusarium root rot of maize was evaluated under greenhouse conditions. Its impacts on plant molecular, pathological, physiological, and growth levels were also studied. Results obtained revealed a potent antagonistic behavior for A. flavus YRB2 against F. solani in vitro, recording 80% growth inhibition. Seventeen secondary metabolites were detected in the n-hexane extract of A. flavus YRB2 filtered culture broth using GC-MS analysis. Among them, various antifungal secondary metabolites were produced, namely palmitic acid, α-linolenic acid, stearic acid, 2, 4-di-tert-butylphenol, diisobutyl phthalate, and heneicosane. In contrast, HPLC analysis showed that no aflatoxins (B1, B2, G1, and G2) were detected. Under greenhouse conditions, colonization of maize plants with A. flavus YRB2 exhibited a potential biocontrol activity against Fusarium root rot, recording 73.4% reduction in the disease severity. Triggering of transcriptional expression level of the defense-related genes JERF3 (7.2-fold), CHI II (8-fold), and POD (9.1-fold) was reported, indicating the inducing effect on the plant immunity. In addition, an increment in the antioxidant enzymes POD and PPO, and the total phenolic content in maize roots was also observed in response to this treatment. Moreover, a growth-promoting effect was also observed for colonization of maize plants with A. flavus YRB2. Based on the obtained data, we can conclude that A. flavus YRB2 may represent a promising biocontrol and growth-promoting agent for maize plants against Fusarium root rot. Nevertheless, field evaluation is highly requested before the use recommendation.


Assuntos
Fusarium , Thymelaeaceae , Antifúngicos/farmacologia , Antioxidantes , Aspergillus flavus/genética , Endófitos/genética , Ácido Palmítico , Fenóis , Doenças das Plantas/prevenção & controle , Zea mays , Ácido alfa-Linolênico
9.
J Med Case Rep ; 16(1): 346, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36175913

RESUMO

BACKGROUND: Fusarium species are saprophytic fungi with a worldwide distribution. These fungi cause various infections among immunocompromised patients; however, they can also involve immunocompetent individuals. CASE PRESENTATION: We report a case of a 41-year-old Iranian woman who presented with ulcerative lesions on her lips 10 months ago. She had a long history of anxiety but had no history of classical risk factors such as trauma, cosmetic lip tattoo, burning in her lips, smoking or use of alcohol and opium. A skin biopsy from the lower lip was performed and sent for microbiological examinations. Hyaline septate hyphae were seen on direct microscopy with potassium hydroxide. The clinical specimen was subcultured on sabouraud dextrose agar with chloramphenicol and prepared for antifungal susceptibility testing and molecular identification. Considering the minimum inhibitory concentrations (MIC) for antifungals, itraconazole (100 mg orally twice a day) was started for her, and after 2 months, the lesions were treated. She followed up for 3 months, and no signs of disease recurrence were observed. CONCLUSIONS: Selecting an appropriate treatment strategy according to the laboratory assessments is essential in clinical practice and the management of rare infections to prevent related mortality and morbidity of opportunistic fungal infections.


Assuntos
Fusarium , Itraconazol , Adulto , Ágar , Antifúngicos/uso terapêutico , Cloranfenicol , Feminino , Glucose , Humanos , Irã (Geográfico) , Itraconazol/uso terapêutico , Lábio , Ópio , Úlcera/tratamento farmacológico
10.
Sci Rep ; 12(1): 16243, 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36171473

RESUMO

Fusarium species include important filamentous fungal pathogens that can infect plants, animals, and humans. Meanwhile, some nonpathogenic Fusarium species are promising biocontrol agents against plant pathogens. Here, we developed a genome editing technology using a vector-based CRISPR/Cas9 system for Fusarium oxysporum f. sp. lycopersici (Fol). This optimized CRISPR/Cas9 system, harboring an endogenous U6 small nuclear RNA promoter for the expression of single-guide RNA and an endogenous H2B nuclear localization signal for the localization of Cas9, enabled efficient targeted gene knock-out, including in the accessory chromosomal regions in Fol. We further demonstrated single crossover-mediated targeted base editing and endogenous gene tagging. This system was also applicable for genome editing in F. oxysporum f. sp. spinaciae and F. commune without any modifications, suggesting that this CRISPR/Cas9 vector has a potential application for a broad range of researches on other Fusarium species.


Assuntos
Fusarium , Edição de Genes , Sistemas CRISPR-Cas/genética , Fusarium/genética , Humanos , Sinais de Localização Nuclear/genética , RNA Guia/genética
11.
Biochemistry ; 61(18): 2025-2035, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36084241

RESUMO

The regiospecific prenylation of an aromatic amino acid catalyzed by a dimethylallyl-l-tryptophan synthase (DMATS) is a key step in the biosynthesis of many fungal and bacterial natural products. DMATS enzymes share a common "ABBA" fold with divergent active site contours that direct alternative C-C, C-N, and C-O bond-forming trajectories. DMATS1 from Fusarium fujikuroi catalyzes the reverse N-prenylation of l-Trp by generating an allylic carbocation from dimethylallyl diphosphate (DMAPP) that then alkylates the indole nitrogen of l-Trp. DMATS1 stands out among the greater DMATS family because it exhibits unusually broad substrate specificity: it can utilize geranyl diphosphate (GPP) or l-Tyr as an alternative prenyl donor or acceptor, respectively; it can catalyze both forward and reverse prenylation, i.e., at C1 or C3 of DMAPP; and it can catalyze C-N and C-O bond-forming reactions. Here, we report the crystal structures of DMATS1 and its complexes with l-Trp or l-Tyr and unreactive thiolodiphosphate analogues of the prenyl donors DMAPP and GPP. Structures of ternary complexes mimic Michaelis complexes with actual substrates and illuminate active site features that govern prenylation regiochemistry. Comparison with CymD, a bacterial enzyme that catalyzes the reverse N-prenylation of l-Trp with DMAPP, indicates that bacterial and fungal DMATS enzymes share a conserved reaction mechanism. However, the narrower active site contour of CymD enforces narrower substrate specificity. Structure-function relationships established for DMATS enzymes will ultimately inform protein engineering experiments that will broaden the utility of these enzymes as useful tools for synthetic biology.


Assuntos
Produtos Biológicos , Dimetilaliltranstransferase , Triptofano Sintase , Catálise , Dimetilaliltranstransferase/química , Fusarium , Hemiterpenos , Indóis , Neopreno , Nitrogênio , Compostos Organofosforados , Prenilação , Especificidade por Substrato , Triptofano/química , Triptofano Sintase/metabolismo
12.
Pestic Biochem Physiol ; 187: 105189, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127064

RESUMO

Rice bakanae disease, caused by Fusarium fujikuroi, is a destructive seed-borne disease throughout the world. Prochloraz, a DMI (C-14α-demethylase inhibitor) fungicide, has been registered in China for >20 years. Prochloraz resistance in F. fujikuroi was severe in China with resistance frequencies of 34.56%, 45.33%, and 48.45% from 2019 to 2021. The fitness of prochloraz-resistant population was lower than that of sensitive population, with an average CFI of 2.86 × 106 and 4.56 × 106, respectively. No cross-resistance was detected between prochloraz and tebuconazole or hexaconazole, and the prochloraz-resistant isolates were still sensitive to fludioxonil, phenamacril, and pydiflumetofen. S312T mutation in Ffcyp51b or overexpression of Ffcyp51a and Ffcyp51b was detected in the highly resistant isolates. AS-PCR primers were designed to detect the prochloraz-resistant isolates with S312T mutation in the field. Resistant isolates carrying S312T mutation were the dominant group in prochloraz-resistant population with frequencies of 43.26%, 23.59%, and 71.20% from 2019 to 2021, which indicated that more attention should be paid to this genotype when monitoring and managing the prochloraz resistance in F. fujikuroi.


Assuntos
Fungicidas Industriais , Fusarium , Fungicidas Industriais/farmacologia , Fusarium/genética , Imidazóis/farmacologia
13.
Plant Physiol Biochem ; 190: 11-23, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36087542

RESUMO

Underground infection of Fusarium oxysporum resulted in great yield losses in chrysanthemum (Chrysanthemum morifolium Ramat.) industry. However, the effect of F. oxysporum root disease on the terpenes production in above- and below-ground parts of plant is completely unexplored. The aim of this study was to investigate the systematic impact of Fusarium infection underground on the terpene production in aboveground parts of chrysanthemum. Terpene production in above- and below-ground parts was profiled in a time series of post-inoculation by GC-MS. Total terpenes were significantly induced from roots and leaves of Fusarium-infected versus healthy plants. These terpenes included monoterpenes, sesquiterpenes and diterpenes, in which sesquiterpenes were primarily induced in roots and leaves, while monoterpenes were produced only in leaves. Through transcriptome analysis, 8 differentially expressed terpene synthase genes (TPSs) were screened out. The relative expression levels of 8 TPS genes at different developmental stage and tissues indicated the spatial delay of the TPS genes in leaves. The induced terpenes from roots and leaves showed consistency with the expression pattern of TPS genes. The biochemical function of Cm-j-TPS1/2/7 were verified by enzymatic assay. Additionally, it's found that the content of salicylic acid (SA) in root and leaf significantly increased by F. oxysporum infection, suggesting a role of the SA signaling pathway in defense. Together, these results reveal the defense response of above- and below-ground parts of plants to root fungal attack and provide a theoretical basis for the effective prediction and control of F. oxysporum infection in chrysanthemum.


Assuntos
Chrysanthemum , Fusariose , Fusarium , Sesquiterpenos , Chrysanthemum/metabolismo , Fusarium/metabolismo , Monoterpenos , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Terpenos
14.
Toxins (Basel) ; 14(9)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36136521

RESUMO

Gibberella ear rot (GER) is an important fungal ear pathogen of maize that causes ear rot and toxin contamination. Most previous works have only dealt with the visual symptoms, but not with the toxins of GER. As food and feed safety rankings depend on toxin contamination, including deoxynivalenol (DON), without toxins, nothing can be said about the risks involved in food and feed quality. Therefore, three susceptible, three medium-susceptible, and three medium-resistant mother lines were crossed with three testers with differing degrees of resistance and tested between 2017-2020. Two plot replicates and two fungal strains were used separately. The highest heterosis was found at the GER% with a 13% increase across 27 hybrids, including 7 hybrids showing negative heterosis (a higher hybrid performance above the parental mean), with a variance ranging between 63.5 and -55.4. For DON, the mean heterosis was negative at -35%, and only 10 of the 27 hybrids showed a positive heterosis. The mean heterosis for DON contamination, at 1% GER, was again negative (-19.6%, varying between 85% and 224%). Only 17 hybrids showed heterosis, while that of the other 17 was rated higher than the parental mean. A positive significant correlation was found only for GER% and DON; the other factors were not significant. Seven hybrids were identified with positive (2) or negative (5) heterosis for all traits, while the rest varied. For DON and GER, only 13 provided identical (positive or negative) heteroses. The majority of the hybrids appeared to diverge in the regulation of the three traits. The stability of GER and DON (variance across eight data sets) did not agree-only half of the genotypes responded similarly for the two traits. The genetic background for this trait is unknown, and there was no general agreement between traits. Thus, without toxin analyses, the evaluation of food safety is not possible. The variety in degrees of resistance to toxigenic fungi and resistance to toxin accumulation is an inevitable factor.


Assuntos
Fusarium , Gibberella , Tricotecenos , Gibberella/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Zea mays/microbiologia
15.
Toxins (Basel) ; 14(9)2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36136530

RESUMO

The contamination of oats with Fusarium toxins poses a high risk for food safety. Among them, trichothecenes are the most frequently reported in European oats, especially in northern countries. The environmental conditions related to the climate change scenario might favour a distribution shift in Fusarium species and the presence of these toxins in Southern European countries. In this paper, we present an ambitious work to determine the species responsible for trichothecene contamination in Spanish oats and to compare the results in the United Kingdom (UK) using a metataxonomic approach applied to both oat grains and soil samples collected from both countries. Regarding T-2 and HT-2 toxin producers, F. langsethiae was detected in 38% and 25% of the oat samples from the UK and Spain, respectively, and to the best of our knowledge, this is the first report of the detection of this fungus in oats from Spain. The relevant type B trichothecene producer, F. poae, was the most frequently detected Fusarium species in oats from both origins. Other important trichothecene producers, such as the Fusarium tricinctum species complex or Fusarium cerealis, were also frequently detected in oat fields. Many Fusarium toxins, including T-2 and HT-2 toxins, deoxynivalenol, or nivalenol, were detected in oat samples. The results obtained in this work revealed a clear change in the distribution of trichothecene producers and the necessity to establish the potential of these species to colonize oats and their ability to produce mycotoxins.


Assuntos
Fusarium , Micotoxinas , Tricotecenos do Tipo B , Tricotecenos , Avena/microbiologia , Grão Comestível/química , Contaminação de Alimentos/análise , Micotoxinas/análise , Solo , Espanha , Toxina T-2/análogos & derivados , Tricotecenos/análise
16.
Toxins (Basel) ; 14(9)2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-36136555

RESUMO

Mycotoxin represents a significant concern for the safety of food and feed products, and wheat represents one of the most susceptible crops. To manage this issue, fast, reliable, and low-cost test methods are needed for regulated mycotoxins. This study aimed to assess the potential use of the electronic nose for the early identification of wheat samples contaminated with deoxynivalenol (DON) above a fixed threshold. A total of 214 wheat samples were collected from commercial fields in northern Italy during the periods 2014-2015 and 2017-2018 and analyzed for DON contamination with a conventional method (GC-MS) and using a portable e-nose "AIR PEN 3" (Airsense Analytics GmbH, Schwerin, Germany), equipped with 10 metal oxide sensors for different categories of volatile substances. The Machine Learning approach "Classification and regression trees" (CART) was used to categorize samples according to four DON contamination thresholds (1750, 1250, 750, and 500 µg/kg). Overall, this process yielded an accuracy of >83% (correct prediction of DON levels in wheat samples). These findings suggest that the e-nose combined with CART can be an effective quick method to distinguish between compliant and DON-contaminated wheat lots. Further validation including more samples above the legal limits is desirable before concluding the validity of the method.


Assuntos
Fusarium , Micotoxinas , Nariz Eletrônico , Contaminação de Alimentos/análise , Micotoxinas/análise , Óxidos , Tricotecenos , Triticum
17.
Toxins (Basel) ; 14(9)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36136558

RESUMO

Agronomic factors can affect mycotoxin contamination of maize, one of the most produced cereals. Maize is usually harvested at 18% moisture, but it is not microbiologically stable until it reaches 14% moisture at the drying plants. We studied how three agronomic factors (crop diversification, tillage system and nitrogen fertilization rate) can affect fungal and mycotoxin contamination (deoxynivalenol and fumonisins B1 and B2) in maize at harvest. In addition, changes in maize during a simulated harvest-till-drying period were studied. DON content at harvest was higher for maize under intensive tillage than using direct drilling (2695 and 474 µg kg-1, respectively). We found two reasons for this: (i) soil crusting in intensive tillage plots caused the formation of pools of water that created high air humidity conditions, favouring the development of DON-producing moulds; (ii) the population of Lumbricus terrestris, an earthworm that would indirectly minimize fungal infection and mycotoxin production on maize kernels, is reduced in intensive tillage plots. Therefore, direct drilling is a better approach than intensive tillage for both preventing DON contamination and preserving soil quality. Concerning the simulated harvest-till-drying period, DON significantly increased between storage days 0 and 5. Water activity dropped on the 4th day, below the threshold for DON production (around 0.91). From our perspective, this study constitutes a step forward towards understanding the relationships between agronomic factors and mycotoxin contamination in maize, and towards improving food safety.


Assuntos
Fumonisinas , Fusarium , Micotoxinas , Contaminação de Alimentos/análise , Micotoxinas/análise , Nitrogênio , Solo , Água , Zea mays/microbiologia
18.
Toxins (Basel) ; 14(9)2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36136565

RESUMO

Fusarium Head Blight is a devastating disease of wheat caused by a complex of Fusarium species producing a wide range of mycotoxins. Fusarium species occurrence is variable in different geographical areas and subjected to a continuous evolution in their distribution. A total of 141 durum wheat field samples were collected in different regions of Italy in three years, and analyzed for Fusarium species and related mycotoxin occurrence. Mycotoxin contamination varied according to year and geographical origin. The highest mycotoxin contamination was detected in 2014. Deoxynivalenol was detected with an average of 240 µg/kg only in Central and Northern Italy; and T-2 and HT-2 toxins with an average of 150 µg/kg in Southern Italy. Approximately 80% of samples from Southern Italy in 2013/2014 showed T-2 and HT-2 levels over the EU recommended limits. Fusarium graminearum occurred mostly in Northern Italy, while F. langsethiae occurred in Southern Italy. These data showed that a real mycotoxin risk related to Fusarium exists on the whole in Italy, but varies according with geographical areas and environmental conditions. Consistent monitoring of Fusarium species and related mycotoxin distribution on a long period is worthwhile to generate more accurate knowledge on Fusarium species profile and mycotoxins associated and better establish the climatic change impact on wheat Fusarium epidemiology.


Assuntos
Fusarium , Micotoxinas , Toxina T-2 , Grão Comestível/química , Contaminação de Alimentos/análise , Itália , Micotoxinas/análise , Toxina T-2/análise , Tricotecenos , Triticum
20.
Int J Mol Sci ; 23(18)2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36142119

RESUMO

For optimal proteolytic function, the proteasome core (CP or 20S) must associate with activators. The cAMP-PKA pathway is reported to affect the activity of the proteasome in humans. However, the relationship between the proteasome and PKA is not well characterized. Our results showed that the major catalytic subunit Cpk1 was degraded without the protection of Pkr. Eleven (out of 67) pkr suppressors had FgBlm10 C-terminal truncation, one suppressor had an amino acid change mutation in the PRE6 ortholog (FGRRES_07282), and one in the PRE5 ortholog (FGRRES_05222). These mutations rescued the defects in growth and conidial morphology, Cpk1 stability, and PKA activities in the pkr mutant. The interaction of FgBlm10 with FgPre5 and FgPre6 were detected by co-immunoprecipitation, and the essential elements for their interaction were characterized, including the FgBlm10 C-terminus, amino acid D82 of FgPre6 and K62 of FgPre5. Additional FgBlm10-interacting proteins were identified in the wild type and pkr mutant, suggesting that PKA regulates the preference of FgBlm10-mediated proteasome assembly. In addition, PKA indirectly affected the phosphorylation of FgBlm10, and its localization in the nucleus. The truncation of the FgBlm10 C terminus also enhanced nuclear import and bleomycin resistance, suggesting its role in proteasome assembly at DNA damage sites. Collectively, our data demonstrated that regulation between PKA and proteasome degradation is critical for the vegetative growth of F. graminearum.


Assuntos
Fusarium , Complexo de Endopeptidases do Proteassoma , Aminoácidos/metabolismo , Bleomicina , Domínio Catalítico , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Fusarium/genética , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo
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