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Pesquisa : G15.610 [Categoria DeCS]
Referências encontradas : 181 [refinar]
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Id: biblio-1087629
Autor: Mendoza, Guillermo; Sánchez-Tafolla, Leonardo; Trigos, Ángel.
Título: Oxidative foliar photo-necrosis produced by the bacteria Pseudomonas cedrina
Fonte: Electron. j. biotechnol;44:14-18, Mar. 2020. ilus, graf.
Idioma: en.
Projeto: Consejo Nacional de Ciencia y Tecnología (CONACYT).
Resumo: BACKGROUND: Although bioactive metabolites capable of causing oxidative photo-necrosis in plant tissues have been identified in fungi, little is known about this type of mechanism in bacteria. These metabolites act as photosensitizers that generate reactive oxygen species (ROS) capable of causing damage to cells. In addition, these metabolites can pass into an energetically excited state when they receive some luminous stimulus, a condition in which they interact with other molecules present in the environment, such as molecular oxygen (O2), also known as triplet oxygen (3 O2), generating ROS. RESULTS: The suspension of the bacterial culture of Pseudomonas cedrina was shown to produce foliar necrosis in papaya leaves (Carica papaya L.) only in the presence of sunlight, which is evidence of photosensitizing mechanisms that generate singlet oxygen (1 O2). From the chemical study of extracts obtained from this bacteria, 3-(4-(2-carboxipropyl) phenyl) but-2-enoic acid (1) was isolated. This compound, in the presence of light and triplet oxygen (3 O2), was able to oxidize ergosterol to its peroxide, since it acted as a photosensitizer producing 1 O2, with which it was corroborated that a photosensitization reaction occurs, mechanism by which this bacterium could prove to cause oxidative foliar photo-necrosis. CONCLUSIONS: P. cedrina was able to induce oxidative foliar photo-necrosis because of its potential ability to produce photosensitizing metabolites that generate singlet oxygen in the plants it colonizes. Based on the above, it can be proposed that some bacteria can cause oxidative foliar photo-necrosis as an important mechanism in the pathogenesis of host species.
Descritores: Doenças das Plantas/microbiologia
Pseudomonas/fisiologia
Carica/microbiologia
Oxigênio Singlete/metabolismo
-Pseudomonas/metabolismo
Ácidos
Espécies Reativas de Oxigênio
Folhas de Planta/microbiologia
Foto-Oxidação
Luz
Necrose
Responsável: CL1.1 - Biblioteca Central


  2 / 181 LILACS  
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Id: biblio-974331
Autor: Guo, Ruiting; Wang, Zhiying; Huang, Ying; Fan, Haijuan; Liu, Zhihua.
Título: Biocontrol potential of saline- or alkaline-tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions
Fonte: Braz. j. microbiol;49(supl.1):236-245, 2018. graf.
Idioma: en.
Projeto: National High Technology Research and Development Program (the 13th Five-Year Plan Program); . Fundamental Research Funds for the Central Universities.
Resumo: ABSTRACT Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana × P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1-T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40 mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62 mM) NaHCO3. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO3 concentrations increased. NaHCO3 tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.
Descritores: Doenças das Plantas/microbiologia
Trichoderma/fisiologia
Cloreto de Sódio/metabolismo
Populus/crescimento & desenvolvimento
Álcalis/metabolismo
Alternaria/fisiologia
Antibiose
-Doenças das Plantas/prevenção & controle
Estresse Fisiológico
Trichoderma/genética
Populus/microbiologia
Plântula/crescimento & desenvolvimento
Plântula/microbiologia
Responsável: BR1.1 - BIREME


  3 / 181 LILACS  
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Azevedo, Joäo L
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Id: biblio-974284
Autor: Elias, Luciana M; Fortkamp, Diana; Sartori, Sérgio B; Ferreira, Marília C; Gomes, Luiz H; Azevedo, João L; Montoya, Quimi V; Rodrigues, André; Ferreira, Antonio G; Lira, Simone P.
Título: The potential of compounds isolated from Xylaria spp. as antifungal agents against anthracnose
Fonte: Braz. j. microbiol;49(4):840-847, Oct.-Dec. 2018. graf.
Idioma: en.
Projeto: FAPESP; . CNPq.
Resumo: ABSTRACT Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46 µmol mL-1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02 µmol mL-1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.
Descritores: Doenças das Plantas/prevenção & controle
Xylariales/química
Paullinia/microbiologia
Endófitos/química
Fungicidas Industriais/farmacologia
-Filogenia
Doenças das Plantas/microbiologia
Espectrometria de Massas
Xylariales/isolamento & purificação
Xylariales/genética
Xylariales/metabolismo
Estrutura Molecular
Colletotrichum/efeitos dos fármacos
Colletotrichum/fisiologia
Endófitos/isolamento & purificação
Endófitos/genética
Endófitos/metabolismo
Fungicidas Industriais/isolamento & purificação
Fungicidas Industriais/química
Responsável: BR1.1 - BIREME


  4 / 181 LILACS  
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Id: biblio-974344
Autor: Hernández-Monjaraz, Wendy Susana; Caudillo-Pérez, César; Salazar-Sánchez, Pedro Ulises; Macías-Sánchez, Karla Lizbeth.
Título: Influence of iron and copper on the activity of laccases in Fusarium oxysporum f. sp. lycopersici
Fonte: Braz. j. microbiol;49(supl.1):269-275, 2018. tab, graf.
Idioma: en.
Projeto: Instituto Politécnico Nacional, Secretaría de Investigación y Posgrado.
Resumo: ABSTRACT Fusarium oxysporum f. sp. lycopersici is a phytopathogenic fungus that causes vascular wilt in tomato plants. In this work we analyze the influence of metal salts such as iron and copper sulphate, as well as that of bathophenanthrolinedisulfonic acid (iron chelator) and bathocuproinedisulfonic acid (copper chelator) on the activity of laccases in the intra (IF) and extracellular fractions (EF) of the wild-type and the non-pathogenic mutant strain (rho1::hyg) of F. oxysporum. The results show that laccase activity in the IF fraction of the wild and mutant strain increased with the addition of iron chelator (53.4 and 114.32%; respectively). With copper, it is observed that there is an inhibition of the activity with the addition of CuSO4 for the EF of the wild and mutant strain (reduction of 82 and 62.6%; respectively) and for the IF of the mutant strain (54.8%). With the copper chelator a less laccase activity in the IF of the mutant strain was observed (reduction of 53.9%). The results obtained suggest a different regulation of intracellular laccases in the mutant strain compared with the wild type in presence of CuSO4 and copper chelator which may be due to the mutation in the rho gene.
Descritores: Proteínas Fúngicas/metabolismo
Cobre/metabolismo
Lacase/metabolismo
Fusarium/enzimologia
Ferro/metabolismo
-Doenças das Plantas/microbiologia
Proteínas Fúngicas/genética
Proteínas Fúngicas/química
Lycopersicon esculentum/microbiologia
Lacase/genética
Lacase/química
Fusarium/genética
Fusarium/química
Responsável: BR1.1 - BIREME


  5 / 181 LILACS  
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Id: biblio-974335
Autor: Naeem, Muhammad; Aslam, Zubair; Khaliq, Abdul; Ahmed, Jam Nazir; Nawaz, Ahmad; Hussain, Mubshar.
Título: Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat
Fonte: Braz. j. microbiol;49(supl.1):9-14, 2018. tab, graf.
Idioma: en.
Resumo: Abstract Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1 tiller−1), and highest plant height (85.8 cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320 m−2), straw yield (8.6 Mg ha−1), and grain yield (4.8 Mg ha−1) were achieved when seeds were inoculated with Bacillus sp. strain 6 + Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6 + Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity.
Descritores: Afídeos/crescimento & desenvolvimento
Pseudomonas/fisiologia
Bacillus/fisiologia
Triticum/crescimento & desenvolvimento
-Doenças das Plantas/parasitologia
Doenças das Plantas/prevenção & controle
Microbiologia do Solo
Triticum/microbiologia
Triticum/parasitologia
Controle Biológico de Vetores
Dinâmica Populacional
Limites: Animais
Responsável: BR1.1 - BIREME


  6 / 181 LILACS  
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Id: biblio-974333
Autor: Vancheva, Taca; Stoyanova, Mariya; Tasheva-Terzieva, Elena; Bogatzevska, Nevena; Moncheva, Penka.
Título: Molecular methods for diversity assessment among xanthomonads of Bulgarian and Macedonian pepper
Fonte: Braz. j. microbiol;49(supl.1):246-259, 2018. tab, graf.
Idioma: en.
Resumo: ABSTRACT Bacterial spot is an important disease of pepper in Bulgaria and Macedonia. For characterization of Xanthomonas species associated with bacterial spot, 161 strains were collected from various field pepper-growing regions. Among them, 131 strains were identified as Xanthomonas euvesicatoria and 30 as Xanthomonas vesicatoria using species-specific primers and polymerase chain reaction followed by restriction fragment length polymorphism analysis. To assess the genetic diversity of the strains, two methods (Random Amplified Polymorphic DNA and Repetitive Element Palindromic-Polymerase Chain Reaction) were applied. Discriminatory index was calculated and analysis of molecular variance was carried out.Combined random amplified polymorphic DNA analysis of the X. euvesicatoria strains with primers CUGEA-4 and CUGEA-6 had greater discriminative power (0.60) than repetitive element palindromic-polymerase chain reaction with ERIC and BOX A1R primers, which makes this method applicable for strain diversity evaluation. Discrimination among the X. vesicatoria strains was achieved by the use of ERIC primers and only for the Bulgarian strains. The results demonstrated that X. euvesicatoria was more diverse than X. vesicatoria and heterogeneity was observed mainly in the Bulgarian populations. According to the analysis of molecular variance, genetic variations in X. euvesicatoria were observed among and within populations from different regions, while the differences between the two countries were minor. Following the principal coordinates analysis, a relation between the climatic conditions of the regions and a genetic distance of the populations may be suggested.
Descritores: Doenças das Plantas/microbiologia
Xanthomonas/isolamento & purificação
Xanthomonas/genética
Capsicum/microbiologia
-Filogenia
Variação Genética
Xanthomonas/classificação
Xanthomonas/fisiologia
Bulgária
Reação em Cadeia da Polimerase
Primers do DNA/genética
Grécia
Responsável: BR1.1 - BIREME


  7 / 181 LILACS  
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Id: biblio-828192
Autor: Darolt, Josiane Cecília; Rocha Neto, Argus Cezar da; Di Piero, Robson Marcelo.
Título: Effects of the protective, curative, and eradicative applications of chitosan against Penicillium expansum in apples
Fonte: Braz. j. microbiol;47(4):1014-1019, Oct.-Dec. 2016. tab, graf.
Idioma: en.
Resumo: Abstract Apple is one of the most important temperate fruit to Brazil economy, and the use of synthetic chemicals has been the main method for reducing postharvest diseases, such as the blue mold, caused by Penicillium expansum. This work intends to evaluate the practical utilization of chitosan for blue mold control. For this purpose, fruits were treated in a preventive and curative way, immersing the fruits in chitosan solution (5 or 10 mg mL-1), or adding a single drop of this solution (10 mg mL-1) directly into the injuries. The eradicative effect of the polysaccharide was also evaluated in vitro and in vivo. Chitosan did not show a curative effect against the blue mold, and its eradicative effect was only evidenced on the higher concentration (10 mg mL-1). On the other hand, preventively, without the addition of adjuvants, chitosan reduced blue mold incidence in fruits by 24% and 93%, through the immersion or the single drop methods, respectively. Thus, it was found that, for long scale utilization, some improvements in the physico-chemical properties of the chitosan are needed, since it was only capable to prevent the infection by P. expansum when directly added on the fruit injury.
Descritores: Penicillium/efeitos dos fármacos
Doenças das Plantas/microbiologia
Doenças das Plantas/terapia
Malus/microbiologia
Quitosana/farmacologia
Antifúngicos/farmacologia
-Doenças das Plantas/prevenção & controle
Fatores de Tempo
Quitosana/química
Frutas/microbiologia
Antifúngicos/química
Responsável: BR1.1 - BIREME


  8 / 181 LILACS  
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Id: biblio-828190
Autor: Ribas e Ribas, Aícha Daniela; Spolti, Pierri; Del Ponte, Emerson Medeiros; Donato, Katarzyna Zawada; Schrekker, Henri; Fuentefria, Alexandre Meneghello.
Título: Is the emergence of fungal resistance to medical triazoles related to their use in the agroecosystems? A mini review
Fonte: Braz. j. microbiol;47(4):793-799, Oct.-Dec. 2016. tab.
Idioma: en.
Resumo: Abstract Triazole fungicides are used broadly for the control of infectious diseases of both humans and plants. The surge in resistance to triazoles among pathogenic populations is an emergent issue both in agriculture and medicine. The non-rational use of fungicides with site-specific modes of action, such as the triazoles, may increase the risk of antifungal resistance development. In the medical field, the surge of resistant fungal isolates has been related to the intensive and recurrent therapeutic use of a limited number of triazoles for the treatment and prophylaxis of many mycoses. Similarities in the mode of action of triazole fungicides used in these two fields may lead to cross-resistance, thus expanding the spectrum of resistance to multiple fungicides and contributing to the perpetuation of resistant strains in the environment. The emergence of fungicide-resistant isolates of human pathogens has been related to the exposure to fungicides used in agroecosystems. Examples include species of cosmopolitan occurrence, such as Fusarium and Aspergillus, which cause diseases in both plants and humans. This review summarizes the information about the most important triazole fungicides that are largely used in human clinical therapy and agriculture. We aim to discuss the issues related to fungicide resistance and the recommended strategies for preventing the emergence of triazole-resistant fungal populations capable of spreading across environments.
Descritores: Triazóis/envenenamento
Ecossistema
Farmacorresistência Fúngica
Agricultura
Fungos/efeitos dos fármacos
Antifúngicos/farmacologia
-Doenças das Plantas/microbiologia
Triazóis/uso terapêutico
Fungos/fisiologia
Fungicidas Industriais
Micoses/microbiologia
Micoses/tratamento farmacológico
Antifúngicos/uso terapêutico
Limites: Humanos
Responsável: BR1.1 - BIREME


  9 / 181 LILACS  
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Id: biblio-828195
Autor: Jadon, Kuldeep Singh; Shah, Rakesh; Gour, Hari Narayan; Sharma, Pankaj.
Título: Management of blight of bell pepper (Capsicum annuum var. grossum) caused by Drechslera bicolor
Fonte: Braz. j. microbiol;47(4):1020-1029, Oct.-Dec. 2016. tab.
Idioma: en.
Resumo: Abstract Sweet or bell pepper is a member of the Solanaceae family and is regarded as one of the most popular and nutritious vegetable. Blight, in the form of leaf and fruit blight, has been observed to infect bell pepper crops cultivated at the horticulture farm in Rajasthan College of Agriculture, Udaipur, India. Based on disease severity, we attempted to curb this newly emerged problem using different fungicides, plant extracts, bio-control agents, and commercial botanicals against the fungus in laboratory and pot experiments. Bio-control agent Trichoderma viride and plant growth promoting Rhizobacteria (PGPR) isolate Neist-2 were found to be quite effective against bell pepper blight. All evaluated fungicides, botanicals, commercial botanicals, and bio-control agents in vitro were further studied as seed dressers and two foliar sprays at ten days interval in pot experiments. The combinations of Vitavax, PGPR isolate Neist-2, and Mehandi extract were found to be very effective against bell pepper blight followed by Vitavax, T. viride, and Mehandi extract used individually. All treatments in the pot experiments were found to significantly reduce seedling mortality and enhance plant biomass of bell pepper. Thus, these experimental findings suggest that a better integrated management of bell pepper blight could be achieved by conducting field trials in major bell pepper- and chilli-cultivated areas of the state. Besides fungicides, different botanicals and commercial botanicals also seem to be promising treatment options. Therefore, the outcome of the present study provides an alternate option of fungicide use in minimizing loss caused by Drechslera bicolor.
Descritores: Doenças das Plantas/microbiologia
Ascomicetos
Capsicum/microbiologia
-Ascomicetos/efeitos dos fármacos
Capsicum/química
Extratos Vegetais/farmacologia
Extratos Vegetais/química
Testes de Sensibilidade Microbiana
Plântula/efeitos dos fármacos
Antifúngicos/farmacologia
Antifúngicos/química
Responsável: BR1.1 - BIREME


  10 / 181 LILACS  
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Id: lil-788969
Autor: Cunty, Amandine; Cesbron, Sophie; Briand, Martial; Carrère, Sébastien; Poliakoff, Françoise; Jacques, Marie-Agnès; Manceau, Charles.
Título: Draft genome sequences of five Pseudomonas syringae pv. actinidifoliorum strains isolated in France
Fonte: Braz. j. microbiol;47(3):529-530, July-Sept. 2016. tab.
Idioma: en.
Resumo: ABSTRACT Pseudomonas syringae pv. actinidifoliorum causes necrotic spots on the leaves of Actinidia deliciosa and Actinidia chinensis. P. syringae pv. actinidifoliorum has been detected in New Zealand, Australia, France and Spain. Four lineages were previously identified within the P. syringae pv. actinidifoliorum species group. Here, we report the draft genome sequences of five strains of P. syringae pv. actinidifoliorum representative of lineages 1, 2 and 4, isolated in France. The whole genomes of strains isolated in New Zealand, representative of P. syringae pv. actinidifoliorum lineages 1 and 3, were previously sequenced. The availability of supplementary P. syringae pv. actinidifoliorum genome sequences will be useful for developing molecular tools for pathogen detection and for performing comparative genomic analyses to study the relationship between P. syringae pv. actinidifoliorum and other kiwifruit pathogens, such as P. syringae pv. actinidiae.
Descritores: Genoma Viral
Análise de Sequência de DNA
Pseudomonas syringae/classificação
Pseudomonas syringae/genética
-Doenças das Plantas/microbiologia
Genômica/métodos
Pseudomonas syringae/isolamento & purificação
Sequenciamento de Nucleotídeos em Larga Escala
Responsável: BR1.1 - BIREME



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