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1.
J Agric Food Chem ; 67(38): 10646-10652, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479255

RESUMO

A new monosesquiterpene diacetylgliocladic acid (1), a new dimeric sesquiterpene divirensol H (9), and two exceptionally novel trimeric sesquiterpene trivirensols A and B (11 and 12), together with another eight known congeners, were purified from an endophytic fungus Trichoderma virens FY06, derived from Litchi chinensis Sonn. whose fruit is a delicious and popular food. All of them were identified by comprehensive spectroscopic analysis, combined with biosynthetic considerations. Trivirensols A and B are unprecedented trimers of which three subunits are connected by two ester bonds of the sesquiterpene class. Relative to the positive control triadimefon, all the tested metabolites showed strong inhibitory activities against at least one phytopathogenic fungus among Penicillium italicum, Fusarium oxysporum, Fusarium graminearum, Colletotrichum musae, and Colletotrictum gloeosporioides. Notably, as metabolites of the endophytic fungus from L. chinensis, they all presented strong antifungal activities against C. gloeosporioides which causes anthracnose in L. chinensis.


Assuntos
Fungicidas Industriais/farmacologia , Litchi/microbiologia , Sesquiterpenos/farmacologia , Trichoderma/química , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Endófitos/química , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Frutas/microbiologia , Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Doenças das Plantas/microbiologia , Sesquiterpenos/química , Sesquiterpenos/metabolismo , Trichoderma/genética , Trichoderma/isolamento & purificação
2.
J Agric Food Chem ; 67(38): 10782-10790, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31490683

RESUMO

Systematic investigation of cyproconazole, including absolute stereochemistry, fungicidal activity, quantification in two matrixes, and stereoselective degradation in cucumber, are conducted in this study. By virtue of vibrational circular dichroism (VCD) spectroscopy, absolute configurations of four stereoisomers were identified to be (2R,3R)-(+)-, (2R,3S)-(+)-, (2S,3S)-(-)-, and (2S,3R)-(-)-cyproconazoles. Then four stereoisomers exhibited stereoselective fungicidal activities against Fusarium graminearum Schw and Magnaporthe oryzae, and the order of fungicidal activity was (2S,3S)-(-)-stereoisomer > the stereoisomer mixture > (2S,3R)-(-)-stereoisomer > (2R,3R)-(+)-stereoisomer > (2R,3S)-(+)-stereoisomer. Moreover, chiral liquid chromatography-tandem mass spectrometry was used to identify and quantify cyproconazole stereoisomers in soil and cucumber matrixes. Good linearity (R2 ≥ 0.99) and recoveries (86.79-92.47%, RSD ≤ 3.94%) for them were achieved, individually. Furthermore, stereoselective degradation of four cyproconazole stereoisomers was observed in cucumber and the order of degradation rate was (2R,3R)-(+)-cyproconazole > (2S,3S)-(-)-cyproconazole > (2R,3S)-(+)-cyproconazole > (2S,3R)-(-)-cyproconazole. We envision that such systematic assessments of chiral fungicides at an enantiomeric level would provide valuable information in future studies involving enantioselective physiological, metabolic, and toxicological activities.


Assuntos
Fungicidas Industriais/química , Triazóis/química , Alternaria/efeitos dos fármacos , Alternaria/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Cucumis sativus/química , Contaminação de Alimentos/análise , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/crescimento & desenvolvimento , Poluentes do Solo/química , Poluentes do Solo/farmacologia , Estereoisomerismo , Espectrometria de Massas em Tandem , Triazóis/farmacologia
3.
Pestic Biochem Physiol ; 158: 149-155, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378351

RESUMO

Induced resistance is an effective measure for controlling plant diseases by utilizing the natural defense of the host and meets the strategic needs of pesticide application and safety for agricultural products worldwide. Ganoderma lucidum polysaccharide (GLP), which is the main active molecule of G. lucidum, has been widely used in functional food and clinical medicine. However, there are few reports of the use of GLP for the prevention and control of plant diseases. The purpose of this study is to explore the effect of GLP and its mechanism of inducing plant resistance. In this study, we found that GLP spray and irrigation root treatments can promote growth in cotton. After soaking in GLP, theseedling height and cotton fusarium wilt resistance both increased to some extent, effects that were dose dependent. After treatment of cotton with GLP, the activities of peroxidase (POD), superoxide dismutase (SOD) and polyphenol oxidase (PPO) in leaves increased significantly, whereas the content of malondialdehyde (MDA) decreased. In addition, QRT-PCR results showed significantly increased relative expression of genes related to the jasmonic acid pathway in cotton. Therefore, we speculate that GLP can induce plant resistance by stimulating the jasmonate pathway.


Assuntos
Fusarium/efeitos dos fármacos , Gossypium/microbiologia , Polissacarídeos/farmacologia , Reishi/química , Antioxidantes/metabolismo , Gossypium/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Doenças das Plantas/microbiologia , Polissacarídeos/química , Superóxido Dismutase/metabolismo
4.
Pestic Biochem Physiol ; 158: 175-184, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378354

RESUMO

Succinate dehydrogenase (SDH), an essential component of cellular respiratory chain and tricarboxylic acid (or Krebs) cycle, has been identified as one of the most significant targets for pharmaceutical and agrochemical. Herein, with the aim of discovery of new antifungal lead structures, a class of novel N-(4-fluoro-2-(phenylamino)phenyl)-pyrazole-4-carboxamides were designed, synthesized and evaluated for their biological activities. They were bioassayed against seven phytopathogenic fungi, Rhizoctonia solani, Phytophthora infestans, Fusarium oxysporum f. sp. vasinfectum, Botryosphaeria dothidea, Gibberella zeae, Alternaria alternate and Fusarium oxysporum f. sp. niveum. The results indicated that most of the compounds displayed good antifungal activities, especially against R. solani. Among them, compounds 7 and 12 exhibited higher antifungal activities against R. solani in vitro with EC50 value of 0.034 mg/L and 0.021 mg/L, being superior to the commercially available fungicide bixafen (EC50 = 0.043 mg/L). Pot tests against R. solani showed that in vivo EC50 values of compounds 7 (2.694 mg/L) and 12 (2.331 mg/L) were higher than that of bixafen (3.724 mg/L). In addition, inhibitory activity of compound 12 against SDH indicated compound 12 (IC50 = 1.836 mg/L) showed good inhibitory activity against SDH, being close to bixafen's inhibitory activity (IC50 = 1.222 mg/L). And, molecular modeling of the SDH-compound 12 complex suggested that compound 12 could strongly bind to and interact with the binding site of the SDH. The results of the present work showed that N-(4-fluoro-2-(phenylamino)phenyl)-pyrazole-4-carboxamides were a new fungicides for discovery of SDH inhibitors and worth further study.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Succinato Desidrogenase/metabolismo , Alternaria/efeitos dos fármacos , Alternaria/enzimologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/enzimologia , Fusarium/efeitos dos fármacos , Fusarium/enzimologia , Phytophthora infestans/efeitos dos fármacos , Phytophthora infestans/enzimologia , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/enzimologia , Relação Estrutura-Atividade
5.
J Med Microbiol ; 68(10): 1489-1496, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31419209

RESUMO

Introduction. The remarkable intrinsic resistance of Fusarium species to most antifungal agents results in high mortality rates in the immunocompromised population.Aims. This study aimed to investigate the epidemiology, clinical features and antifungal susceptibility of Fusarium isolates in patients with invasive fusariosis.Methodology. A total of 27 patients admitted to a referral hospital from January 2008 to June 2017 were evaluated. Antifungal susceptibility testing of isolates was performed by broth microdilution according to the Clinical and Laboratory Standards Institute guidelines.Results. Haematological malignancy was the predominant underlying condition, with an incidence of invasive fusariosis of 14.8 cases per 1000 patients with acute lymphoid leukaemia and 13.1 cases per 1000 patients with acute myeloid leukaemia. The Fusarium solani species complex (FSSC) was the most frequent agent group, followed by the Fusarium oxysporum species complex (FOSC). Voriconazole showed the best activity against Fusarium, followed by amphotericin B. Itraconazole showed high minimum inhibitory concentration values, indicating in vitro resistance. Clinical FSSC isolates were significantly (P<0.05) more resistant to amphotericin B and voriconazole than FOSC isolates.Conclusion. The present antifungal susceptibility profiles indicate a high incidence of fusariosis in patients with haematological malignancy. Species- and strain-specific differences in antifungal susceptibility exist within Fusarium in this setting.


Assuntos
Fusariose/microbiologia , Fusarium/efeitos dos fármacos , Fusarium/isolamento & purificação , Neoplasias Hematológicas/microbiologia , Adolescente , Adulto , Idoso , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Fusariose/epidemiologia , Fusarium/classificação , Fusarium/genética , Neoplasias Hematológicas/epidemiologia , Humanos , Itraconazol/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Filogenia , Voriconazol/farmacologia , Adulto Jovem
6.
Plant Dis ; 103(10): 2536-2540, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31424998

RESUMO

Fusarium head blight, also called scab, is caused by Fusarium graminearum and is one of the most important destructive diseases of wheat. The frequency of carbendazim resistance in 1,132 isolates of F. graminearum recovered from fields in different regions of Henan Province in 2016, 2017, and 2018 was determined. A total of 31 F. graminearum isolates resistant to carbendazim were detected, including 30 moderately resistant isolates and one highly resistant isolate. The frequency of resistance of F. graminearum isolates to carbendazim was 2.7%. The range of effective concentration (EC50) values of 1,101 sensitive isolates and 30 moderately resistant isolates was 0.08 to 0.98 µg ml-1 and 2.73 to 13.28 µg ml-1, respectively. The mean ± SD EC50 value was 0.55 ± 0.13 µg ml-1 and 5.61 ± 2.58 µg ml-1, respectively. The EC50 value of the highly resistant isolate was 21.12 µg ml-1. Point mutation types of the carbendazim-resistant isolates were characterized by cloning the ß2-tubulin gene of 31 resistant isolates. Three point mutation types at amino acids F167Y, E198Q, and E198L in the ß2-tubulin gene of resistant isolates were identified. Among 31 resistant isolates, the frequency of point mutation types in F167Y, E198Q, and E198L of the ß2-tubulin gene was 71.0, 25.8, and 3.2%, respectively. The data indicate that F. graminearum has developed resistance to carbendazim in Henan Province, and single point mutations at amino acid F167Y were the predominant type of mutation detected.


Assuntos
Benzimidazóis , Carbamatos , Farmacorresistência Fúngica , Fusarium , Triticum , Benzimidazóis/farmacologia , Carbamatos/farmacologia , Farmacorresistência Fúngica/genética , Fungicidas Industriais , Fusarium/efeitos dos fármacos , Fusarium/genética , Genes de Plantas/genética , Mutação Puntual , Triticum/microbiologia , Tubulina (Proteína)/genética
7.
Chemosphere ; 233: 873-878, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340413

RESUMO

The cyanoacrylate ethyl (2Z)-3-amino-2-cyano-3-phenylacrylate (phenamacril), has been introduced as an effective agent against several fungi species belonging to the Fusarium genus. However, in current literature, knowledge about the environmental behavior of this fungicide is limited and there are no data on the degradation in the environment. By performing tests on inherent degradability as well as degradation studies in soils this study provides the only published information regarding the environmental stability and degradation kinetics of this compound. Tests for inherent/ready biodegradation revealed the phenamacril is inherently degradable with zero order kinetics, even though the degradation is comparatively slow. Degradation of phenamacril in soil was found to occur following first order kinetics with a final plateau with a half live of 17.1 days (i.e. more rapidly than tebuconazole but less rapidly than octylisothiazolinone).


Assuntos
Biodegradação Ambiental , Cianoacrilatos/análise , Fungicidas Industriais/análise , Esgotos/química , Poluentes do Solo/análise , Solo/química , Fusarium/efeitos dos fármacos , Triazóis/análise
8.
J Agric Food Chem ; 67(33): 9220-9231, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31347838

RESUMO

Slow-release fungicide formulations (azoxystrobin, epoxiconazole, and tebuconazole) shaped as pellets and granules in a matrix of biodegradable poly(3-hydroxybutyrate) and natural fillers (clay, wood flour, and peat) were constructed. Infrared spectroscopy showed no formation of chemical bonds between components in the experimental formulations. The formulations of pesticides had antifungal activity against Fusarium verticillioides in vitro. A study of biodegradation of the experimental fungicide formulations in the soil showed that the degradation process was mainly influenced by the type of formulation without significant influence of the type of filler. More active destruction of the granules led to a more rapid accumulation of fungicides in the soil. The content of fungicides present in the soil as a result of degradation of the formulations and fungicide release was determined by their solubility. Thus, all formulations are able to function in the soil for a long time, ensuring gradual and sustained delivery of fungicides.


Assuntos
Argila/química , Preparações de Ação Retardada/química , Composição de Medicamentos/métodos , Fungicidas Industriais/química , Hidroxibutiratos/química , Poliésteres/química , Solo/química , Madeira/química , Preparações de Ação Retardada/farmacologia , Portadores de Fármacos/química , Composição de Medicamentos/instrumentação , Compostos de Epóxi/química , Compostos de Epóxi/farmacologia , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Cinética , Pirimidinas/química , Pirimidinas/farmacologia , Estrobilurinas/química , Estrobilurinas/farmacologia , Triazóis/química , Triazóis/farmacologia
9.
Int J Food Microbiol ; 306: 108259, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31349113

RESUMO

Cereal grains are essential ingredient in food, feed and industrial processing. One of the major causes of cereal spoilage and mycotoxin contamination is the presence of toxigenic Fusarium spp. Nanoparticles have immense applications in agriculture, nutrition, medicine or health but their possible impact on the management of toxigenic fungi and mycotoxins have been very little explored. In this report, the potential of silver nanoparticles (AgNPs) (size 14-100 nm) against the major toxigenic Fusarium spp. affecting crops and their effect on mycotoxin accumulation is evaluated for the first time. The studied Fusarium spp. (and associated mycotoxins) were F. graminearum and F. culmorum (deoxynivalenol, 3-acetyldeoxynivalenol and zearalenone), F. sporotrichioides and F. langsethiae (T-2 and HT-2 toxins), F. poae (nivalenol), F. verticillioides and F. proliferatum (fumonisins B1 and B2) and F. oxysporum (mycotoxins no detected). The factors fungal species, AgNP dose (range 2-45 µg/mL), exposure time (range 2-30 h) and their interactions significantly influence spore viability, lag period and growth rate (GR) in subsequent cultures in maize-based medium (MBM) of all the studied species. The effective lethal doses (ED50, ED90 and ED100) to control spore viability and GR were in the range 1->45 µg/mL depending on the remaining factors. At high exposure times (20-30 h), the three effective doses ranged 1-30 µg/mL for all the studied species. At the end of the incubation period (10 days) mycotoxin levels in MBM cultures inoculated with fungal spores from treatments were strongly related with the size reached by the colony at that time. None of the treatments produced stimulation in conidia germination, GR or mycotoxin biosynthesis with respect to controls. Thus, the antifungal effect of the assayed AgNPs against the tested Fusarium spp. suggests that AgNPs could be a new antifungal ingredient in bioactive polymers (paints, films or coating) likely to be implemented in the agro-food sector for controlling these important toxigenic Fusarium spp. and their main associated mycotoxins.


Assuntos
Antifúngicos/farmacologia , Grão Comestível/microbiologia , Fusarium/efeitos dos fármacos , Nanopartículas Metálicas , Micotoxinas/análise , Prata/farmacologia , Contaminação de Alimentos/análise , Fumonisinas/análise , Testes de Sensibilidade Microbiana , Toxina T-2/análogos & derivados , Toxina T-2/análise , Tricotecenos/análise , Zea mays/microbiologia , Zearalenona/análise
10.
Plant Dis ; 103(8): 1974-1982, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31210598

RESUMO

Fusarium solani is an emerging pathogen reported on Spanish strawberry crops both in nurseries and in fruit production fields, causing wilt and root rot. Pathogenicity, morphocultural characteristics, and sensitivity to biocides of 103 F. solani isolates recovered from symptomatic strawberry plants and soils from both Spanish strawberry areas were determined. The differences of isolates within and between nurseries and field crops in relation to these parameters were analyzed. Considerable variability in morphological and pathogenic characteristics was observed among the isolates in both areas. The majority of isolates were not pathogenic (62%), and only 38 F. solani isolates (37.62%) caused disease on strawberry plants under controlled conditions; 52.63% of pathogenic isolates induced low severity symptoms. Almost 70% of pathogenic isolates caused stunting on plants. The morphological characters that best explain the F. solani variability (86.85%) were colony color and the presence of macroconidia on culture medium. The sensitivity to the fumigants tested was similar between the isolates from nurseries and fruit production fields, showing greater sensitivity to the field doses of dazomet and chloropicrin. However, the isolates were less sensitive to metam sodium and poorly sensitive to 1,3-dichloropropene. This work can contribute to the advancement of sustainable production of strawberry.


Assuntos
Fragaria , Fusarium , Desinfetantes/farmacologia , Fragaria/microbiologia , Fusarium/efeitos dos fármacos , Fusarium/fisiologia , Doenças das Plantas/microbiologia , Microbiologia do Solo
11.
Plant Dis ; 103(8): 1858-1864, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31242132

RESUMO

Although there has been research on managing Fusarium head blight (FHB) in spring barley, little has been published on cultivar resistance and optimal fungicide timing for FHB management in winter barley. A 3-year (2015 to 2017) field experiment was conducted to measure FHB resistance of winter barley varieties, gauge the potential benefit from a fungicide, and help determine the optimal timing for fungicide application. The split-plot experiment took place in a misted, inoculated nursery in Raleigh, North Carolina using main plots of four winter barley cultivars (Atlantic, Endeavor, Nomini, and Thoroughbred). Three fungicide treatments were applied to subplots: prothioconazole + tebuconazole at full spike emergence, the same fungicide 6 days later, or no fungicide. The late applications significantly reduced FHB index in each of 3 years and significantly reduced deoxynivalenol (DON) in harvested grain in 2 of the 3 years. Applications at full spike emergence also yielded significant benefit in 1 of the 3 years for each parameter. Neither disease symptoms nor DON gave reason to prefer one of the fungicide timings over the other. Across the 3 years, DON ranked the cultivars Endeavor < Nomini = Thoroughbred < Atlantic. Combining the moderate resistance of Endeavor with a fungicide application and averaging the two timings resulted in a 75% DON reduction compared with unsprayed Atlantic. Taken together, our results indicate that barley growers concerned about minimizing DON should both plant moderately resistant varieties and apply fungicide if there is scab risk. During the same period, 16 commercial winter barley cultivars were tested in from three to seven Virginia and North Carolina environments each, and the DON results were compared after standardization across environments. The winter two-row malting barley cultivars Endeavor and Calypso displayed superior and robust DON resistance across environments.


Assuntos
Resistência à Doença , Fungicidas Industriais , Fusarium , Hordeum , Resistência à Doença/genética , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/fisiologia , Hordeum/classificação , Hordeum/genética , Hordeum/microbiologia , North Carolina , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Virginia
12.
Pestic Biochem Physiol ; 157: 45-52, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31153476

RESUMO

Herein, we describe the enhanced antifungal activity of silver nanoparticles biosynthesized by cell free filtrate of Trichoderma viride (MTCC 5661) in comparison to chemically synthesized silver nanoparticles (CSNP) of similar shape and size. Biosynthesized silver nanoparticles (BSNP) enhanced the reduction in dry weight by 20 and 48.8% of fungal pathogens Fusarium oxysporum and Alternaria brassicicola respectively in comparison to their chemical counterparts (CSNP). Nitroblue tetrazolium and Propidium iodide staining demonstrated the higher generation of superoxide radicals lead to higher death in BSNP treated fungus in comparison to CSNP. Scanning electron microscopy of A. brassicicola revealed the osmotic imbalance and membrane disintegrity to be major cause for fungal cell death after treatment with BSNP. To gain an insight into the mechanistic aspect of enhanced fungal cell death after treatment of BSNP in comparison to CSNP, stress responses and real time PCR analysis was carried out with A. brassicicola. It revealed that generation of ROS, downregulation of antioxidant machinery and oxidative enzymes, disruption of osmotic balance and cellular integrity, and loss of virulence are the mechanisms employed by BSNP which establishes them as superior antifungal agent than their chemical counterparts. With increasing drug resistance and ubiquitous presence of fungal pathogens in plant kingdom, BSNP bears the candidature for new generation of antifungal agent.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Nanopartículas Metálicas/química , Doenças das Plantas/microbiologia , Prata/química , Alternaria/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo
13.
Carbohydr Polym ; 220: 1-11, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31196526

RESUMO

Chitosans are versatile biopolymers recognized for their wide range of biological activities. However, the low solubility in neutral and basic solutions restricts the applications. Thus amphiphilic biopolymeric Schiff bases from chitosans, salicylaldehyde and glycidol were successfully synthesized and characterized using 1H-NMR, UV/Vis, FTIR, TG/DTG-DTA and tested for their antimicrobial activities against plant pathogenic microorganisms and human breast cancer cells (MCF-7). Overall, functionalization of chitosans with salicylaldehyde and glycidol with different molecular weight (Mw¯) was performed to improve the biological actives of chitosans. Thus the biological activity of the new amphiphilic compounds prepared in this work were evaluated regarding microorganisms with agricultural relevance and tumor cells. The biopolymeric amphiphilic Schiff bases showed significant effects against Pseudomonas syringae (IC50 < 5 µg mL-1) compared to the natural chitosans with medium Mw¯ (CHM 223 kDa) and low Mw¯ (CHL 64 kDa), which had IC50 values of 42 and 37 µg mL-1, respectively. In addition, they improved antitumor activity against tumor cells compared to the natural chitosan.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Quitosana , Fusarium/efeitos dos fármacos , Pseudomonas syringae/efeitos dos fármacos , Bases de Schiff , Animais , Células 3T3 BALB , Quitosana/análogos & derivados , Quitosana/química , Quitosana/farmacologia , Humanos , Células MCF-7 , Camundongos , Testes de Sensibilidade Microbiana/métodos , Peso Molecular , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacologia , Solubilidade
14.
Fungal Biol ; 123(5): 408-422, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31053330

RESUMO

DNA damage can cause mutations that in fungal plant pathogens lead to hypervirulence and resistance to pesticides. Almost nothing is known about the response of these fungi to DNA damage. We performed transcriptomic and phosphoproteomic analyses of Fusarium oxysporum exposed to methyl methanesulfonate (MMS). At the RNA level we observe massive induction of DNA repair pathways including the global genome nucleotide excision. Cul3, Cul4, several Ubiquitin-like ligases and components of the proteasome are significantly induced. In agreement, we observed drug synergism between a proteasome inhibitor and MMS. While our data suggest that Yap1 and Xbp1 networks are similarly activated in response to damage in yeast and F. oxysporum we were able to observe modules that were MMS-responsive in F. oxysporum and not in yeast. These include transcription/splicing modules that are upregulated and respiration that is down-regulated. In agreement, MMS treated cells are much more sensitive to a respiration inhibitor. At the phosphoproteomic level, Adenylate cyclase, which generates cAMP, is phosphorylated in response to MMS and forms a network of phosphorylated proteins that include cell cycle regulators and several MAPKs. Our analysis provides a starting point in understanding how genomic changes in response to DNA damage occur in Fusarium species.


Assuntos
Dano ao DNA , Fusarium/efeitos dos fármacos , Metanossulfonato de Metila/metabolismo , Mutagênicos/metabolismo , Reparo do DNA , Perfilação da Expressão Gênica , Fosfoproteínas/análise , Doenças das Plantas/microbiologia , Proteoma/análise , Estresse Fisiológico
15.
Molecules ; 24(9)2019 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-31060338

RESUMO

A new series of coumarin derivatives, 7-hydroxy-7-(trifluoromethyl)-6a,12b-dihydro-6H,7H-chromeno[3,4-c]chromen-6-ones 3a-p, were synthesized via Michael addition, transesterification and nucleophilic addition from the reaction of 3-trifluoroacetyl coumarins and phenols in the presence of an organic base. The products were characterized by infrared spectroscopy (IR), hydrogen nuclear magnetic resonance spectroscopy (1H-NMR), carbon nuclear magnetic resonance spectroscopy (13C-NMR) and high-resolution mass spectrometer (HRMS). Single crystal X-ray analysis of compounds 3a and 3n clearly confirmed their assigned chemical structures and their twisted conformations. Compound 3a crystallized in the orthorhombic system, Pbca, in which a = 8.6244(2) Å, b = 17.4245(4) Å, c = 22.5188(6) Å, α = 90°, ß = 90°, γ = 90°, v = 3384.02(14) Å3, and z = 8. In addition, the mycelial growth rate method was used to examine the in vitro antifungal activities of the title compounds 3a-p against Fusarium graminearum and Fusarium monitiforme at 500 µg/mL. The results showed that compound 3l exhibited significant anti-Fusarium monitiforme activity with inhibitory index of 84.6%.


Assuntos
Antifúngicos/síntese química , Benzopiranos/síntese química , Cumarínicos/química , Fusarium/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/farmacologia , Benzopiranos/química , Benzopiranos/farmacologia , Cristalografia por Raios X , Testes de Sensibilidade Microbiana , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética , Relação Estrutura-Atividade
16.
IET Nanobiotechnol ; 13(2): 219-225, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051454

RESUMO

Silver nanoparticles (Ag NPs) were synthesised using the crude ethyl acetate extracts of Ulva lactuca and evaluated their bioefficacy against two crop-damaging pathogens. The sets of lattice planes in the XRD spectrum for the Ag NPs were indexed to the 111, 200, 220 and 311 orientations and support the crystalline nature of the Ag NPs. The 3414 and 2968 cm-1 peaks were observed in crude algal thallus extract and they were characteristic of terpenoids. Further, a peak at 1389 cm-1 was observed as fatty acids. The marine macroalgae terpenoids and palmitic acid acted as reducing agent and stabiliser, respectively. The size (3 and 50 nm) and shape (spherical) of Ag NPs were recorded. The energy-dispersive X-ray spectroscopy analysis exemplified the presence of silver in its elemental nature. Moreover, U. lactuca Ag NPs were effective against two cotton phytopathogens namely Fusarium oxysporum f.sp. vasinfectum (FOV) and Xanthomonas campestris pv. malvacearum (XAM). The minimum inhibitory concentration was found to be 80.0 and 43.33 µg ml-1 against FOV and XAM, respectively. Results confirmed the anti-microbial activity of green nanoparticles against select pathogens and suggest their possible usage in developing antifungal agents for controlling destructive pathogens in a cotton agroecosystem.


Assuntos
Gossypium/microbiologia , Nanopartículas Metálicas/química , Doenças das Plantas/prevenção & controle , Alga Marinha/química , Prata/metabolismo , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Fusarium/efeitos dos fármacos , Química Verde/métodos , Tamanho da Partícula , Doenças das Plantas/microbiologia , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Prata/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ulva/química
17.
Plant Dis ; 103(8): 1850-1857, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31140924

RESUMO

Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most damaging diseases that affect wheat in Canada. The disease is best managed by integrating host resistance and fungicides, mainly demethylation inhibitors. Research has shown that the effect of fungicides may be dependent on the level of resistance of the cultivar. However, whether the performance of genotypes carrying specific Sumai 3-derived major FHB quantitative trait loci is dependent on fungicide application has not been explored. In our study, the performance of near-isogenic lines (NILs; <1.0% genome/alleles from the resistance donor), carrying Fhb1 and Fhb5 in a hard red spring wheat cultivar CDC Go background compared with a moderately susceptible (MS) genotype, was evaluated with and without one application of metconazole during full flowering. Field experiments were conducted at five site-years in Saskatchewan, Canada, between 2016 and 2017. In both the individual and combined analysis (all trials), we found that the effect of NILs and metconazole in suppressing FHB symptoms and deoxynivalenol (DON) accumulation in the grain was additive. FHB severity was generally low and fungicide efficacy levels, relative to the untreated control, were increased in the MS cultivar than in the NILs carrying Fhb1 and Fhb5, which were least affected by the disease. The results confirm the importance of integrating fungicides with cultivar resistance to reduce FHB and DON, regardless of the presence of those well-characterized resistant genes.


Assuntos
Fungicidas Industriais , Fusarium , Locos de Características Quantitativas , Triticum , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/fisiologia , Saskatchewan , Triticum/genética
18.
Braz J Infect Dis ; 23(3): 197-199, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31129063

RESUMO

We report a patient with fungal keratitis caused by a multiresistant Fusarium solani in a tertiary care hospital located in southern Brazil. A 55-year-old man with a history of ocular trauma presented with keratitis in left eye. The patient has a complicated clinical course and failed to respond to local and systemic antifungal treatment, and required eye enucleation. Despite multiple topical, intraocular and systemic antifungal treatments, hyphal infiltration persisted in the corneal transplant causing continuous recurrences. The cultures of corneal biopsy scrapings were positive for Fusarium spp. The organism was identified to species level by multi-locus sequencing for translation elongation factor 1 alpha (EF-1α), and RNA polymerase II subunit (RPB2). In vitro antifungal susceptibility testing of the isolate by the broth microdilution method, according to CLSI M38-A2, disclosed susceptibility to natamycin and resistance to amphotericin B, voriconazole, itraconazole and fluconazole. Considering previous unsuccessful antifungal treatments due to multiple drug resistance, the eye was enucleated. Our case report illustrates that management of fungal keratitis remains a therapeutic challenge. Optimal treatment for F. solani infection has not yet been established and should include susceptibility testing for different antifungal agents.


Assuntos
Antifúngicos/administração & dosagem , Fusarium/efeitos dos fármacos , Ceratite/microbiologia , Antifúngicos/farmacologia , Enucleação Ocular , Humanos , Ceratite/cirurgia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Falha de Tratamento
19.
J Microbiol ; 57(6): 485-497, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31134579

RESUMO

Fusarium solani has drawn phytopathogenic, biotechnological, and medical interest. In humans, it is associated with localized infections, such as onychomycosis and keratomycosis, as well as invasive infections in immunocompromised patients. One pathogenicity factor of filamentous fungi is biofilm formation. There is still only scarce information about the in vitro mechanism of the formation and composition of F. solani biofilm. In this work, we describe the biofilm formed by a clinical keratomycosis isolate in terms of its development, composition and susceptibility to different antifungals and ultraviolet light (UV) at different biofilm formation stages. We found five biofilm formation stages using scanning electron microscopy: adherence, germination, hyphal development, maturation, and cell detachment. Using epifluorescence microscopy with specific fluorochromes, it was elucidated that the extracellular matrix consists of carbohydrates, proteins, and extracellular DNA. Specific inhibitors for these molecules showed significant biofilm reductions. The antifungal susceptibility against natamycin, voriconazole, caspofungin, and amphotericin B was evaluated by metabolic activity and crystal violet assay, with the F. solani biofilm preformation to 24 h increased in resistance to natamycin, voriconazole, and caspofungin, while the biofilm preformation to 48 h increased in resistance to amphotericin B. The preformed biofilm at 24 h protected and reduced UV light mortality. F. solani isolate could produce a highly structured extra biofilm; its cellular matrix consists of carbohydrate polymers, proteins, and eDNA. Biofilm confers antifungal resistance and decreases its susceptibility to UV light. The fungal biofilm functions as a survival strategy against antifungals and environmental factors.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos da radiação , Infecções Oculares Fúngicas/microbiologia , Fusarium/efeitos dos fármacos , Fusarium/efeitos da radiação , Ceratite/microbiologia , Farmacorresistência Fúngica/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos da radiação , Fungos/efeitos dos fármacos , Fungos/efeitos da radiação , Fusarium/patogenicidade , Humanos , Hifas/efeitos dos fármacos , Hifas/efeitos da radiação , México , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Microscopia Eletrônica de Varredura
20.
Plant Dis ; 103(7): 1712-1720, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31059383

RESUMO

Sudden death syndrome (SDS), caused by Fusarium virguliforme, is an important soilborne disease of soybean. Risk of SDS increases when cool and wet conditions occur soon after planting. Recently, multiple seed treatment and foliar products have been registered and advertised for management of SDS but not all have been tested side by side in the same field experiment at multiple field locations. In 2015 and 2016, seed treatment fungicides fluopyram and thiabendazole; seed treatment biochemical pesticides citric acid and saponins extract of Chenopodium quinoa; foliar fungicides fluoxastrobin + flutriafol; and an herbicide, lactofen, were evaluated in Illinois, Indiana, Iowa, Michigan, South Dakota, Wisconsin, and Ontario for SDS management. Treatments were tested on SDS-resistant and -susceptible cultivars at each location. Overall, fluopyram provided the highest level of control of root rot and foliar symptoms of SDS among all the treatments. Foliar application of lactofen reduced foliar symptoms in some cases but produced the lowest yield. In 2015, fluopyram reduced the foliar disease index (FDX) by over 50% in both resistant and susceptible cultivars and provided 8.9% yield benefit in susceptible cultivars and 3.5% yield benefit in resistant cultivars compared with the base seed treatment (control). In 2016, fluopyram reduced FDX in both cultivars by over 40% compared with the base seed treatment. For yield in 2016, treatment effect was not significant in the susceptible cultivar while, in the resistant cultivar, fluopyram provided 3.5% greater yield than the base seed treatment. In this study, planting resistant cultivars and using fluopyram seed treatment were the most effective tools for SDS management. However, plant resistance provided an overall better yield-advantage than using fluopyram seed treatment alone. Effective seed treatments can be an economically viable consideration to complement resistant cultivars for managing SDS.


Assuntos
Proteção de Cultivos , Fungicidas Industriais , Fusarium , Soja , Proteção de Cultivos/métodos , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Ontário , Doenças das Plantas/prevenção & controle , Sementes/química , Soja/crescimento & desenvolvimento , Estados Unidos
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