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1.
Microbiol Res ; 227: 126294, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421718

RESUMO

After exposure to with Populus davidiana × P. alba var. pyramidalis, the expression of genes in Trichoderma asperellum were compared in four transcriptomes. The top 20 high expression genes included six heat shock proteins and three hydrophobins, indicating that Trichoderma can rapidly adapt to environment stresses and elicit a plant defense response. The genes, involved in the interaction between Trichoderma and plant, showed an increasing expression level, for example sugar transporters, EPL1s, endoxylanases, pectin lyases, and nitrilases. Interestingly, sugar transporters also showed high expression when T. asperellum was cultured on medium lacking a carbon substrate, which would contribute to T. asperellum's survival and domination in ecological niche competition. And the genes related to mycoparasitism were expressed abundantly following T. asperellum's interaction with PdPap, indicating the PdPap induction could enhance the mycoparasitic ability of T. asperellum. Twelve chitinases and five glucanases showed higher expression in transcriptome Cs, indicating that T. asperellum secretes both types of enzyme before interacting with pathogens, allowing T. asperellum to implement mycoparasitism and obtain more energy. Many novel transcripts were obtained in each transcriptome, which may play important roles in the biocontrol process of T. asperellum. Interestingly, T. asperellum undergo constitutive alternative splicing in the biocontrol process: Seven biocontrol genes were alternative spliced via intron retention. qRT-PCR analysis proved that intron retention is negatively associated with the expression of chitinase, oligopeptide transporters, and beta-lactamase. However, the percentage of MAPK intron retention was quite low, suggesting that intron retention has little effect on the function of MAPK.


Assuntos
Agentes de Controle Biológico/farmacologia , Doenças das Plantas/microbiologia , Populus/microbiologia , Transcriptoma , Trichoderma/efeitos dos fármacos , Trichoderma/genética , Trichoderma/metabolismo , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Genes Fúngicos/genética , Proteínas de Choque Térmico/genética , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Estresse Fisiológico/genética
2.
Microbiol Res ; 228: 126301, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422232

RESUMO

The in vitro inhibition of quorum sensing signal, xanthan gum secretion, biofilm formation in different Xanthomonas pathovars and biological control of bacterial blight of rice by the two bioactive extrolites produced by Pseudomonas aeruginosa strain CGK-KS-1 were explored. These extrolites were extracted from Diaion HP-20 resin with methanol and purified by preparative-thin layer chromatography. Further, spectroscopic structural elucidation revealed the tentative identity of these extrolites to be (R,3E,5E,9Z,11E)-13-((3S,5R)-5-acetyl-2,6-dimethylheptan-3-yl)-10-hydroxy-4-methyl-1,8-diazabicyclo[9.3.1]pentadeca-3,5,9,11(15),13-pentaen-2-one and (R,3E,5E,8E,11E)-13-((3S,5R)-5-acetyl-2,6-dimethylheptan-3-yl)-4-methyl-1,8-diazabicyclo[9.3.1]pentadeca-3,5,8,11(15),13-pentaene-2,10-dione, named as Chumacin-1 and Chumacin-2, respectively. Antimicrobial assay showed Chumacin-1 and Chumacin-2 exhibited a strong in vitro growth inhibition against various Xanthomonas pathovars. Quorum sensing overlay assay using a reporter strain Chromobacterium violaceum strain CV026 showed that Chumacin-1 and Chumacin-2 inhibited quorum sensing signaling. The mechanistic studies revealed that these extrolites inhibited the production of quorum sensing signaling factor, cis-11-methyl-2-dodecenoic acid; suppressed the xanthan gum secretion and also inhibited the biofilms formed by various Xanthomonas pathovars. Both Chumacin-1 and Chumacin-2 showed ROS generation in the test Xanthomonas strains, resulting in in vitro cell membrane damage was revealed through CSLM and FE-SEM micrographs. Further, greenhouse experiments using Samba Mashuri (BPT-5204) revealed that seed treatment with Chumacin-1 and Chumacin-2 along with foliar spray groups showed up to ˜80% reduction in bacterial blight disease in rice. To the best of our knowledge, this is the first report on new quorum sensing inhibitors, Chumacin-1 and Chumacin-2 produced by Pseudomonas aeruginosa strain CGK-KS-1 exhibiting DSF inhibition activity in Xanthomonas oryzae pv. oryzae.


Assuntos
Agentes de Controle Biológico/isolamento & purificação , Agentes de Controle Biológico/farmacologia , Oryza/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas aeruginosa/metabolismo , Percepção de Quorum/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Xanthomonas/efeitos dos fármacos , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Agentes de Controle Biológico/química , Chromobacterium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Doenças das Plantas/microbiologia , Polissacarídeos Bacterianos/metabolismo , Poliestirenos , Xanthomonas/metabolismo
3.
Microbiol Res ; 226: 41-47, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284943

RESUMO

Myzus persicae Sulzer (Hemiptera: Aphididae), is a generalist cosmopolitan insect that infests more than 400 plant species of 40 different families and is one of the major pests infesting potato crops. It causes direct damage and also spread plant viruses. The intensive use of synthetic insecticide to control aphids has led to resistant populations. Therefore, there is a need to develop biopesticides for effective control that minimizes environmental hazards. The bacteria Bacillus amyloliquefaciens is recognized as a producer of a variety of bioactive compounds. The aim here was to evaluate the aphicidal effect of B. amyloliquefaciens strains, CBMDDrag3, PGPBacCA2, and CBMDLO3, and their metabolites on the mortality and fecundity of M. persicae. Cells suspensions, heat-killed cell suspensions, cell-free supernatants, or isolated lipopeptide fractions from B. amyloliquefaciens strains were offered to aphids through artificial diets. The isolated lipopeptide fractions composed mainly of kurstakins, surfactins, iturins, and fengycins, when were administrated through diets, had no aphicidal effect against M. persicae. However, aphids fed on diets with whole cell suspensions and its cell-free supernatant of all three bacteria strains resulted in 100% mortality of adult aphids and nymphs. Specially, B. amyloliquefaciens CBMDLO3, has an effective aphicidal effect on M. persicae, used both bacterial cells and their metabolites. Moreover, heat-killed cells of B. amyloliquefaciens CBMDLO3 also had aphicidal action, although the aphid mortality was lower than on diet with living bacteria. Therefore, these results propose that B. amyloliquefaciens, could function as a novel eco-friendly biopesticide for the control of M. persicae.


Assuntos
Afídeos/efeitos dos fármacos , Afídeos/microbiologia , Bacillus amyloliquefaciens/metabolismo , Controle Biológico de Vetores , Animais , Bacillus amyloliquefaciens/isolamento & purificação , Agentes de Controle Biológico/isolamento & purificação , Agentes de Controle Biológico/metabolismo , Agentes de Controle Biológico/farmacologia , Feminino , Controle de Insetos/métodos , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Inseticidas/farmacologia , Lipopeptídeos/isolamento & purificação , Lipopeptídeos/metabolismo , Lipopeptídeos/farmacologia , Doenças das Plantas/parasitologia , Doenças das Plantas/prevenção & controle
4.
Environ Sci Pollut Res Int ; 26(18): 17996-18000, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31090005

RESUMO

Synthetic pesticides are largely decried. A common attitude against the synthetic agrochemicals is to avoid, criticise or ban these substances. Along with chemical pesticides to defend crops from bioagressors are microorganisms, semiochemical and natural substances used as plant protection products including biocontrol agents (BCAs) and crop protection products in organic production. Nevertheless, a natural substance status does not confer or imply safety, security or absence of residues (in the context of plant protection). Although in this paper we do not consider the toxicological perspective of highly toxic chemicals with adverse effects on humans and non-target organisms sprayed on crops, we have applied ourselves to working on the safe use of synthetic agrochemicals. Thus, along with biopesticides (either BCA or others) allowed in organic farming, we show that some synthetic chemical pesticides may be used in safe manner. HIGHLIGHTS: • Synthetic agrochemicals are widely criticised. • Some pesticide usages are not sprayed on crops. • Some biocontrol agents are of synthetic origin.


Assuntos
Agroquímicos/análise , Agentes de Controle Biológico/análise , Proteção de Cultivos/métodos , Produtos Agrícolas , Agroquímicos/farmacologia , Agentes de Controle Biológico/farmacologia , Proteção de Cultivos/economia , Proteção de Cultivos/legislação & jurisprudência , Produtos Agrícolas/química , Produtos Agrícolas/efeitos dos fármacos , União Europeia , Humanos , Resíduos de Praguicidas/análise
5.
Environ Sci Pollut Res Int ; 26(19): 19705-19718, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31089999

RESUMO

Leaf blast is the main rice disease in the world causing significant losses in productivity. Blast integrate management (BIM) requires the use of genetic resistance, cultural practices, and chemical control, although for sustainable BIM, the insertion of biological agents may be the fourth component for. The objective of this work was to test three formulations of Burkholderia pyrrocinia (BRM32113) previously selected and to verify the effectiveness in resistance induction and blast control in rice. Two experiments were carried out, in a completely randomized design with three replications, in the greenhouse (E1 and E2). E1 aimed to select the best treatment for suppressing leaf blast severity and activating plant defense mechanisms. It was composed of 8 treatments: (1) formulated 11+ B. pyrrocina × Magnaporthe oryzae; (2) formulated 17+ B. pyrrocina × M. oryzae; (3) formulated 32+ B. pyrrocina × M. oryzae; (4) formulated 11 × M. oryzae; (5) B. pyrrocinia 17 × M. oryzae; (6) formulated 32 × M. oryzae; (7) B. pyrrocina × M. oryzae; (8) M. oryzae; (9) control (water). E2 aimed to investigate the effect of the best treatments, for the promotion of plant growth and suppression of leaf blast by calculating AUDPC. It was composed of 6 treatments: (1) formulated 11+ B. pyrrocina × M. oryzae; (2) formulated 32+ B. pyrrocina × M. oryzae; (3) formulated 11 × M. oryzae; (4) formulated 32 × M. oryzae; (5) B. pyrrocina × M. oryzae; (6) water. And after, we did two assays aimed to localize this biological agent after application at seed, soil, and rice plant. In E1, formulated 11+ B. pyrrocinia and 32+ formulated and B. pyrrocina were the best, suppressing leaf blast by up to 97% and providing the significant increase of the enzymes ß-1,3-glucanase, chitinase, phenylalanine ammonia lyase, lipoxygenase, and salicylic acid at 24 h and 48 h after inoculation with M. oryzae. In E2, treatments formulated 11+ B. pyrrocinia, formulated 32+ B. pyrrocinia, and B. pyrrocina provided more significant increases in growth promotion and reduced area under disease progress curve. B. pyrrocinia was detected in the rice plant for 18 days, predominantly in the root system (internal and external). The use of B. pyrrocinia formulations based on sugarcane molasses and glycerol can be an essential strategy for sustainable management. Although all the benefits come from these sustainable formulations, the adoption by commercial biological segment depends on an established formulation process. It seems that all the results showed here by this research will be readily assimilated by startups of the organic segment.


Assuntos
Agentes de Controle Biológico/farmacologia , Burkholderia , Resistência à Doença/efeitos dos fármacos , Magnaporthe , Oryza/microbiologia , Doenças das Plantas/prevenção & controle , Agentes de Controle Biológico/isolamento & purificação , Burkholderia/metabolismo , Magnaporthe/crescimento & desenvolvimento , Oryza/enzimologia , Doenças das Plantas/microbiologia , Folhas de Planta/enzimologia , Folhas de Planta/microbiologia , Distribuição Aleatória , Ácido Salicílico/metabolismo
6.
J Microbiol ; 57(5): 396-404, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31062286

RESUMO

Aspergillus flavus is a saprophytic fungus that contaminates crops with carcinogenic aflatoxin. In the present work, the antifungal effects of volatile organic compounds (VOCs) from Streptomyces alboflavus TD-1 against A. flavus were investigated. VOCs from 8-day-old wheat bran culture of S. alboflavus TD-1 displayed strong inhibitory effects against mycelial growth, sporulation, and conidial germination of A. flavus. Severely misshapen conidia and hyphae of A. flavus were observed by scanning electron microscopy after exposure to VOCs for 6 and 12 h, respectively. Rhodamine 123 staining of mitochondria indicated that mitochondria may be a legitimate antifungal target of the VOCs from S. alboflavus TD-1. Furthermore, the VOCs effectively inhibited aflatoxin B1 production by downregulating genes involved in aflatoxin biosynthesis. Dimethyl trisulfide and benzenamine may play important roles in the suppression of A. flavus growth and production of aflatoxin. The results indicate that VOCs from S. alboflavus TD-1 have tremendous potential to be developed as a useful bio-pesticide for controlling A. flavus.


Assuntos
Aflatoxina B1/biossíntese , Antifúngicos/farmacologia , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Agentes de Controle Biológico/farmacologia , Streptomyces/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Aflatoxina B1/genética , Antifúngicos/metabolismo , Agentes de Controle Biológico/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Sulfetos/farmacologia , Compostos Orgânicos Voláteis/metabolismo
7.
World J Microbiol Biotechnol ; 35(5): 72, 2019 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-31011844

RESUMO

Bacterial diseases caused by members of the genus Xanthomonas affect agricultural crops of great importance in the world. At least 350 different plant diseases are caused by species of Xanthomonas. Important crops, such as: rice, citrus, cassava, tomato, sugar cane, passionfruit and brassicas are severely affected by bacteria of this genus. Due to its rapid propagation, handling difficulties, problems with chemical control and severity of the losses of the affected plantations Xanthomonas is a difficult obstacle for agriculture around the world. In addition, chemical control of some of these diseases is carried out using copper-based chemicals, which causes a negative impact on health and the environment. A more sustainable alternative to combat these diseases is the control of Xanthomonas by microorganisms directly or indirectly through the use of its secondary metabolites involved in biocontrol. This review is a report concerning the recent advances in the search for microorganisms for the biocontrol of several Xanthomonas that are important for the world economy.


Assuntos
Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Xanthomonas/patogenicidade , Bactérias/metabolismo , Agentes de Controle Biológico/metabolismo , Agentes de Controle Biológico/farmacologia , Produtos Agrícolas/microbiologia , Fungos/metabolismo , Controle Biológico de Vetores/métodos , Metabolismo Secundário , Xanthomonas/classificação , Xanthomonas/efeitos dos fármacos , Xanthomonas campestris/patogenicidade
8.
Nat Microbiol ; 4(6): 996-1005, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30833726

RESUMO

Beneficial microorganisms are widely used in agriculture for control of plant pathogens, but a lack of efficacy and safety information has limited the exploitation of multiple promising biopesticides. We applied phylogeny-led genome mining, metabolite analyses and biological control assays to define the efficacy of Burkholderia ambifaria, a naturally beneficial bacterium with proven biocontrol properties but potential pathogenic risk. A panel of 64 B. ambifaria strains demonstrated significant antimicrobial activity against priority plant pathogens. Genome sequencing, specialized metabolite biosynthetic gene cluster mining and metabolite analysis revealed an armoury of known and unknown pathways within B. ambifaria. The biosynthetic gene cluster responsible for the production of the metabolite cepacin was identified and directly shown to mediate protection of germinating crops against Pythium damping-off disease. B. ambifaria maintained biopesticidal protection and overall fitness in the soil after deletion of its third replicon, a non-essential plasmid associated with virulence in Burkholderia cepacia complex bacteria. Removal of the third replicon reduced B. ambifaria persistence in a murine respiratory infection model. Here, we show that by using interdisciplinary phylogenomic, metabolomic and functional approaches, the mode of action of natural biological control agents related to pathogens can be systematically established to facilitate their future exploitation.


Assuntos
Agentes de Controle Biológico/metabolismo , Agentes de Controle Biológico/farmacologia , Burkholderia/genética , Burkholderia/metabolismo , Lactonas/metabolismo , Lactonas/farmacologia , Animais , Sequência de Bases , Complexo Burkholderia cepacia/genética , DNA Bacteriano/genética , Modelos Animais de Doenças , Genes Bacterianos/genética , Camundongos , Família Multigênica , Filogenia , Doenças das Plantas/microbiologia , Plasmídeos , Pythium/efeitos dos fármacos , Pythium/patogenicidade , Proteínas Repressoras/classificação , Proteínas Repressoras/genética , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologia , Microbiologia do Solo , Transativadores/classificação , Transativadores/genética , Virulência
9.
Arch Microbiol ; 201(6): 713-722, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30868174

RESUMO

The genus Pantoea contains a broad range of plant-associated bacteria, including some economically important plant pathogens as well as some beneficial members effective as biological control agents of plant pathogens. The most well-characterized representatives of biological control agents from this genus generally produce one or more antimicrobial compounds adding to biocontrol efficacy. Some Pantoea species evaluated as biocontrol agents for fire blight disease of apple and pear produce a histidine-reversible antibiotic. Three commonly studied histidine-reversible antibiotics produced by Pantoea spp. are herbicolin O, MccEh252, and pantocin A. Pantocin A is a novel ribosomally encoded and post-translationally modified peptide natural product. Here, we review the current knowledge on the chemistry, genetics, biosynthesis, and incidence and environmental relevance of pantocin A and related histidine-reversible antibiotics produced by Pantoea.


Assuntos
Agentes de Controle Biológico/metabolismo , Glicopeptídeos/metabolismo , Pantoea/metabolismo , Peptídeos/metabolismo , Doenças das Plantas/microbiologia , Agentes de Controle Biológico/química , Agentes de Controle Biológico/farmacologia , Glicopeptídeos/química , Glicopeptídeos/farmacologia , Pantoea/química , Pantoea/genética , Peptídeos/química , Peptídeos/farmacologia
10.
Acta Trop ; 193: 192-198, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30836061

RESUMO

BACKGROUND: Oil formulations of entomopathogenic fungi have interest for biological mosquito control. OBJECTIVES: The activities of M. anisopliae s.l. IP 46 conidia were tested in Aedes aegypti adults either without any formulation or formulated with vegetable or mineral oil and in combination with diatomaceous earth. FINDINGS: IP 46 was highly active against adults, the vector of important arboviruses in the tropics and subtropics. At an exposure of adults to 3.3 × 107 conidia/cm2, values of lethal times TL50 and TL90 reached minimal 3.8 and 4.6 days, respectively, and lethal concentrations LC50 and LC90 were 2.7 × 105 and 2.4 × 106 conidia/cm2, respectively, after 10 days of exposure. Activity against adults was improved by diatomaceous earth (KeepDry® KD) combined with mineral oil (Naturol® N) or vegetable oil (Graxol® G). Additives KD or N separately (and G to a lesser extent) or in combination, KD + N and KD + G without conidia had also a clear adulticidal effect. Efficacy of conidia formulated or not with KD + N decreased somewhat at shorter exposure periods. Time of exposure (0.017, 12, 48, 72 or 120 h) of adults to KD and N or IP 46 or conidia and KD and N had no significant effect on mortality. M. anisopliae s.l. recycled on fungus-killed mosquitoes producing high quantities of new conidia regardless of the conidial concentrations or formulations tested. Additives tested had no clear effect on quantitative conidiogenesis on cadavers. MAIN CONCLUSIONS: Formulations of IP 46 conidia with mineral oil and diatomaceous earth represent a promising tool for the development of potent strategies of focal control of this important vector with entomopathogenic fungi.


Assuntos
Aedes/efeitos dos fármacos , Agentes de Controle Biológico/farmacologia , Metarhizium/crescimento & desenvolvimento , Controle Biológico de Vetores , Esporos Fúngicos/crescimento & desenvolvimento , Aedes/microbiologia , Animais , Terra de Diatomáceas/farmacologia , Feminino , Inseticidas/farmacologia , Óleo Mineral/farmacologia , Controle de Mosquitos , Mosquitos Vetores/efeitos dos fármacos , Óleos Vegetais/farmacologia
11.
Sci Total Environ ; 667: 33-40, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30825819

RESUMO

The plant microbiome is known to be influenced by certain biotic as well as abiotic factors. Nevertheless, the drivers for specific changes in microbial community composition and structure are largely unknown. In the present study, the effects of chemical and biological treatments for plant protection on the indigenous microbiome of Camellia sinensis (L.) Kuntze were contrasted. Assessment of bacteria-specific ribosomal RNA gene fragment amplicons from a representative set of samples showed an increased microbial diversity in treated plants when compared to untreated samples. Moreover, distinct microbial fingerprints were found for plants subjected to a conventional pesticide treatment with lime sulfur as well as for plants that were biologically treated with a Piriformospora indica spore solution. The bacterial community of pesticide-treated plants was augmented by 11 taxa assigned to Proteobacteria and Actinobacteria. In contrast, plants from biological control treatments were augmented by 10 taxa representing a more diversified community enrichment and included members of Actionobacteria, Proteobacteria, Bacteroidetes, Planctomycetes, and Verrucomicrobia. Complementary, molecular quantification of fungi in the samples showed a significantly lower number of internal transcribed spacer copies in plants subjected to biological control treatments, indicating the highest efficiency against fungal pathogens. The overall results show that leaves that are used for tea production show distinct microbiome shifts that are elicited by common pest and pathogen management practices. These shifts in the microbial population indicate non-target effects of the applied treatments.


Assuntos
Bactérias/efeitos dos fármacos , Agentes de Controle Biológico/farmacologia , Camellia sinensis/microbiologia , Fungos/efeitos dos fármacos , Herbicidas/farmacologia , Microbiota/efeitos dos fármacos , Basidiomycota/fisiologia , Compostos de Cálcio/farmacologia , Folhas de Planta/microbiologia , Sulfetos/farmacologia
12.
Microbiol Res ; 221: 28-35, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30825939

RESUMO

Endophytic fungi belonging to Muscodor genus are considered as promising alternatives to be used in biological control due to the production of volatile organic compounds (VOCs). The strains LGMF1255 and LGMF1256 were isolated from the medicinal plant Schinus terebinthifolius and, by morphological data and phylogenetic analysis, identified as belonging to Muscodor genus. Phylogenetic analysis suggests that strain LGMF1256 is a new species, which is herein introduced as Muscodor brasiliensis sp. nov. The analysis of VOCs production revealed that compounds phenylethyl alcohol, α-curcumene, and E (ß) farnesene until now has been reported only from M. brasiliensis, data that supports the classification of strain LGMF1256 as a new species. M. brasiliensis completely inhibited the phytopathogen P. digitatum in vitro. We also evaluated the ability of VOCs from LGMF1256 to inhibit the development of green mold symptoms by inoculation of P. digitatum in detached oranges. M. brasiliensis reduced the severity of diseases in 77%, and showed potential to be used for fruits storage and transportation to prevent the green mold symptoms development, eventually reducing the use of fungicides.


Assuntos
Antifúngicos/farmacologia , Agentes de Controle Biológico/farmacologia , Penicillium/efeitos dos fármacos , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Xylariales/metabolismo , Anacardiaceae/microbiologia , Antifúngicos/metabolismo , Agentes de Controle Biológico/metabolismo , Fungicidas Industriais , Penicillium/crescimento & desenvolvimento , Álcool Feniletílico/metabolismo , Sesquiterpenos/metabolismo , Xylariales/isolamento & purificação
13.
Microbiol Res ; 221: 60-69, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30825942

RESUMO

Bacteria isolated from different environments can be exploited for biocontrol purposes by the identification of the molecules involved in the antifungal activity. The present study was aimed at investigating antifungal protein compounds purified from a previously identified plant growth promoting bacterium, Pseudomonas protegens N isolated from agricultural land in northern Algeria. Therefore, a novel protein was purified by chromatographic and ultrafiltration steps and its antifungal activity together with growth-inhibition mechanism was evaluated against different fungi by plate-based assays. In addition, stereomicroscopy and transmission electron microscopy (TEM) was performed to explore the inhibition activity of the compound on spore germination processes. The protein, showing a molecular mass of about 100 kDa under native conditions, was revealed to be in the surface-membrane fraction and displayed an efficient activity against a variety of phytopathogenic fungi, being Alternaria the best target towards which it exhibited a marked fungicidal action and inhibition of spore germination. Moreover, the compound was able to significantly decrease fungal infection on tomato fruits producing also morphological aberrations on conidia. The obtained results suggested that the isolated compound could represent a promising agent for eco-friendly management of plant pathogens in agriculture.


Assuntos
Alternaria/crescimento & desenvolvimento , Antifúngicos/farmacologia , Agentes de Controle Biológico/farmacologia , Pseudomonas/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Argélia , Alternaria/efeitos dos fármacos , Lycopersicon esculentum/microbiologia , Testes de Sensibilidade Microbiana , Desenvolvimento Vegetal/fisiologia , Reguladores de Crescimento de Planta/metabolismo , Plantas/microbiologia , Pseudomonas/isolamento & purificação , Rizosfera , Microbiologia do Solo , Esporos Fúngicos/efeitos dos fármacos
14.
PLoS One ; 14(2): e0207735, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30753194

RESUMO

Within family Baculoviridae, members of the Betabaculovirus genus are employed as biocontrol agents against lepidopteran pests, either alone or in combination with selected members of the Alphabaculovirus genus. Epinotia aporema granulovirus (EpapGV) is a fast killing betabaculovirus that infects the bean shoot borer (E. aporema) and is a promising biopesticide. Because occlusion bodies (OBs) play a key role in baculovirus horizontal transmission, we investigated the composition of EpapGV OBs. Using mass spectrometry-based proteomics we could identify 56 proteins that are included in the OBs during the final stages of larval infection. Our data provides experimental validation of several annotated hypothetical coding sequences. Proteogenomic mapping against genomic sequence detected a previously unannotated ac110-like core gene and a putative translation fusion product of ORFs epap48 and epap49. Comparative studies of the proteomes available for the family Baculoviridae highlight the conservation of core gene products as parts of the occluded virion. Two proteins specific for betabaculoviruses (Epap48 and Epap95) are incorporated into OBs. Moreover, quantification based on emPAI values showed that Epap95 is one of the most abundant components of EpapGV OBs.


Assuntos
Baculoviridae/genética , Genoma Viral/genética , Brotos de Planta/virologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Agentes de Controle Biológico/farmacologia , Genômica/métodos , Lepidópteros/efeitos dos fármacos , Fases de Leitura Aberta/genética , Proteoma/genética
15.
Pestic Biochem Physiol ; 153: 67-76, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30744898

RESUMO

Jaburetox (Jbtx) is an insecticidal peptide derived from Canavalia ensiformis urease, whose mechanism of action is not completely elucidated. We employed behavioral, electromyographical and electrophysiological protocols to identify the cellular and molecular targets involved in the Jbtx entomotoxicity in cockroaches and locusts. In Nauphoeta cinerea, Jbtx (32 µg/g) altered the locomotory behaviour inducing a significative decrease in the distance travelled followed by a significant increase in stopped time (52 ±â€¯85 cm and 2573 ±â€¯89 s, p < .05, n = 40). Jbtx (8 to 32 µg/g body weight, respectively) also increased the leg and antennae grooming activities (p < .05, n = 40, respectively). Jbtx (8 to 16 µg/g) induced a maximum neuromuscular blockade of 80.72% (n = 6, p < .05) and was cardiotoxic, decreasing the cockroach heart rate. The electrophysiological profiles of both muscle and nerve of L. migratoria showed that Jbtx (2.5 × 10-7 and 2.5 × 10-3 µg/ body weight) induced a significant increase in the amplitude of nerve action potentials (n = 5, p < .05). Voltage clamp analysis of Jbtx (200 nM) applied in Xenopus laevis oocytes heterologously expressed with Nav 1.1 channels showed a significant increase in the sodium currents. In conclusion, this work revealed that the entomotoxic activity of Jbtx involves complex behavioral alterations that begins with an initial activation of voltage-gated sodium channels.


Assuntos
Agentes de Controle Biológico/farmacologia , Baratas/efeitos dos fármacos , Gafanhotos/efeitos dos fármacos , Inseticidas/farmacologia , Urease/farmacologia , Canais de Sódio Disparados por Voltagem/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Baratas/fisiologia , Feminino , Gafanhotos/fisiologia , Locomoção/efeitos dos fármacos , Masculino
16.
World J Microbiol Biotechnol ; 35(3): 40, 2019 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-30739227

RESUMO

Grey mould caused by Botrytis cinerea is among the most important disease affecting the production of grapevine worldwide. The high economical loss each year has led producers to become more dependent on chemical pesticides for protection. However, environmental impacts of the pesticides overuse have sparked crescent interest in developing alternative biocontrol methods. The use of plant-associated bacteria has, thus, received many attentions as a promising strategy for sustainable agriculture. Three strains, isolated from the rhizosphere of crops cultivated in the northeast of France, were evaluated for their antagonistic effect. They were found to exhibit an antagonistic effect against a set of phytopathogenic fungi. Phenotypic and molecular characterization showed that isolates belong to the genus Burkholderia. The genome sequencing and analysis of isolated strains revealed the presence of gene clusters coding for secondary metabolites potentially involved in the biocontrol. When the grapevine plantlets were infected with B. cinerea, all plants associated with isolated strains showed a significant protection against B. cinerea compared to non-inoculated plants. To understand the mechanisms contributing to the biocontrol effect of selected isolates, the production of reactive oxygen species (ROS) and the expression of several defense genes were investigated. The maximum accumulation of H2O2 was detected in the inoculated cell suspension medium 30 min after the challenge with B. cinerea. After pathogen challenge, results showed that grapevine cell culture inoculated with isolated strains exhibited significant over expression of defense markers genes PR5, PR10, and chit4c, in response to B. cinerea, confirming their priming effect.


Assuntos
Antibiose/genética , Agentes de Controle Biológico/farmacologia , Botrytis/efeitos dos fármacos , Burkholderia/genética , Burkholderia/metabolismo , Doenças das Plantas/prevenção & controle , Vitis/microbiologia , Antibiose/fisiologia , Agentes de Controle Biológico/isolamento & purificação , Botrytis/crescimento & desenvolvimento , Botrytis/patogenicidade , Burkholderia/classificação , Burkholderia/isolamento & purificação , Produtos Agrícolas/microbiologia , França , Regulação Bacteriana da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes Bacterianos/genética , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Família Multigênica , Fosfatos/metabolismo , Filogenia , Doenças das Plantas/microbiologia , RNA Ribossômico 16S/genética , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/farmacologia , Rizosfera , Metabolismo Secundário/genética , Sideróforos/metabolismo , Microbiologia do Solo , Vitis/genética , Vitis/metabolismo , Sequenciamento Completo do Genoma
17.
J Environ Sci Health B ; 54(5): 366-375, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30729858

RESUMO

The loss of yields from agricultural production due to the presence of pests has been treated over the years with synthetic pesticides, but the use of these substances negatively affects the environment and presents health risks for consumers and animals. The development of agroecological systems using biopesticides represents a safe alternative that contributes to the reduction of agrochemical use and sustainable agriculture. Microalgae are able to biosynthesize a number of metabolites with potential biopesticidal action and can be considered potential biological agents for the control of harmful organisms to soils and plants. The present work aims to provide a critical perspective on the consequences of using synthetic pesticides, offering as an alternative the biopesticides obtained from microalgal biomass, which can be used together with the implementation of environmentally friendly agricultural systems.


Assuntos
Agricultura/métodos , Agentes de Controle Biológico/farmacologia , Microalgas/química , Praguicidas/farmacologia , Animais , Humanos , Praguicidas/química , Medição de Risco , Desenvolvimento Sustentável
18.
Appl Microbiol Biotechnol ; 103(3): 1189-1215, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30603850

RESUMO

Overuse of broad-spectrum antibiotics to control human and plant pathogens greatly accelerated the development of antibiotic resistance among bacteria and fungi. Therefore, usage of new approaches is necessary to control outbreaks of phytopathogenic diseases as well as multidrug-resistant human pathogens. Many of the polyketides (PKs) and lipopetides (LPs) produced by Bacillus and Paenibacillus species have been described as antimicrobial agents that can be potentially applied as sustainable bio-organic products in medicine against human pathogens and in agriculture for controlling plant pathogens. The present review provides a general information about the classification and biochemical structure of known Bacillus- and Paenibacillus-secreted PKs, as well as ribosomally and nonribosomally synthesized peptides, their functional features, gene clusters involved in their production, and the mode of action of these metabolites.


Assuntos
Anti-Infecciosos/farmacologia , Bacillus/metabolismo , Bacteriocinas/farmacologia , Agentes de Controle Biológico/farmacologia , Lipopeptídeos/farmacologia , Paenibacillus/metabolismo , Doenças das Plantas/prevenção & controle , Policetídeos/farmacologia , Anti-Infecciosos/metabolismo , Bacillus/genética , Bacteriocinas/metabolismo , Agentes de Controle Biológico/metabolismo , Farmacorresistência Bacteriana Múltipla , Humanos , Lipopeptídeos/metabolismo , Paenibacillus/genética , Plantas , Policetídeos/metabolismo
19.
PLoS Negl Trop Dis ; 13(1): e0006948, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668561

RESUMO

The human disease schistosomiasis (or bilharzia) is caused by the helminth blood fluke parasite Schistosoma mansoni, which requires an intermediate host, the freshwater gastropod snail Biomphalaria glabrata (the most common intermediate host). The free-swimming parasite miracidia utilise an excellent chemosensory sense to detect and locate an appropriate host. This study investigated the biomolecules released by the snail that stimulate changes in the behaviour of the aquatic S. mansoni miracidia. To achieve this, we have performed an integrated analysis of the snail-conditioned water, through chromatography and bioassay-guided behaviour observations, followed by mass spectrometry. A single fraction containing multiple putative peptides could stimulate extreme swimming behaviour modifications (e.g. velocity, angular variation) similar to those observed in response to crude snail mucus. One peptide (P12;-R-DITSGLDPEVADD-KR-) could replicate the stimulation of miracidia behaviour changes. P12 is derived from a larger precursor protein with a signal peptide and multiple dibasic cleavage sites, which is synthesised in various tissues of the snail, including the central nervous system and foot. P12 consists of an alpha helix secondary structure as indicated by circular dichroism spectroscopy. This information will be helpful for the development of approaches to manipulate this parasites life cycle, and opens up new avenues for exploring other parasitic diseases which have an aquatic phase using methods detailed in this investigation.


Assuntos
Agentes de Controle Biológico/farmacologia , Biomphalaria/química , Descoberta de Drogas/métodos , Peptídeos/farmacologia , Feromônios/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Animais , Anti-Helmínticos/farmacologia , Humanos , Esquistossomose/tratamento farmacológico
20.
Microbiol Res ; 219: 123-131, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30642463

RESUMO

Pseudomonas sp. MP12 was isolated from a soil sample collected in a typical warm-temperate deciduous forest near Brescia, Northern Italy. Phylogenetic analysis identified the species as Pseudomonas protegens. We evidenced in this strain the presence of the genes phlD, pltB and prnC responsible for the synthesis of the antifungal compounds 2,4-diacetylphloroglucinol (2,4-DAPG), pyoluteorin and pyrrolnitrin, respectively. P. protegens MP12 was also shown to produce siderophores and ammonia, yielded positive results with the indole-3-acetic acid test, and was capable of phosphate solubilization. Moreover, P. protegens MP12 exhibited inhibitory effects on in vitro mycelial growth of prominent grapevine (Vitis vinifera) phytopathogens such as Botrytis cinerea, Alternaria alternata, Aspergillus niger, Penicillium expansum and Neofusicoccum parvum. The strain showed activity even against Phaeomoniella chlamydospora and Phaeoacremonium aleophilum, which cause the devastating tracheomycosis/esca disease of grapevine trunks for which no efficacious control methods have been demonstrated so far. Furthermore, the MP12 strain manifested in vivo antifungal activity against B. cinerea on grapevine leaves. Culture-dependent and culture-independent analysis revealed the ability of P. protegens MP12 to efficiently and permanently colonize inner grapevine tissues. These results suggest that P. protegens MP12 could be worth of exploitation as an antifungal biocontrol agent for applications in viticulture.


Assuntos
Antifúngicos/metabolismo , Agentes de Controle Biológico/metabolismo , Fungos/efeitos dos fármacos , Fenóis/metabolismo , Floroglucinol/análogos & derivados , Pseudomonas/metabolismo , Pirróis/metabolismo , Pirrolnitrina/metabolismo , Vitis/microbiologia , Antifúngicos/farmacologia , Agentes de Controle Biológico/farmacologia , Endófitos/metabolismo , Fenóis/farmacologia , Floroglucinol/metabolismo , Floroglucinol/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , Folhas de Planta/microbiologia , Pseudomonas/isolamento & purificação , Pirróis/farmacologia , Pirrolnitrina/farmacologia , Microbiologia do Solo , Vitis/crescimento & desenvolvimento
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