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1.
J Sci Food Agric ; 102(2): 696-706, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34173241

RESUMO

BACKGROUND: Microorganism for biological control of fruit diseases is an eco-friendly alternative to the use of chemical fungicides. RESULTS: This is the first study evaluating the electrospraying process to encapsulate the biocontrol yeast Meyerozyma caribbica. The effect of encapsulating material [Wey protein concentrate (WPC), Fibersol® and Trehalose], its concentration and storage temperature on the cell viability of M. caribbica, and in vitro and in vivo control of Colletotrichum gloeosporioides was evaluated. The processing with commercial resistant maltodextrin (Fibersol®) 30% (w/v) as encapsulating material showed the highest initial cell viability (95.97 ± 1.01%). The storage at 4 ± 1 °C showed lower losses of viability compared to 25 ± 1 °C. Finally, the encapsulated yeast with Fibersol 30% w/v showed inhibitory activity against anthracnose in the in vitro and in vivo tests, similar to yeast fresh cells. CONCLUSION: Electrospraying was a highly efficient process due to the high cell viability, and consequently, a low quantity of capsules is required for the postharvest treatment of fruits. Additionally, the yeast retained its antagonistic power during storage. © 2021 Society of Chemical Industry.


Assuntos
Agentes de Controle Biológico/química , Agentes de Controle Biológico/farmacologia , Carica/microbiologia , Colletotrichum/efeitos dos fármacos , Composição de Medicamentos/métodos , Mangifera/microbiologia , Saccharomycetales/química , Antibiose , Colletotrichum/crescimento & desenvolvimento , Composição de Medicamentos/instrumentação , Frutas/microbiologia , Viabilidade Microbiana , Saccharomycetales/fisiologia
2.
Int J Mol Sci ; 22(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34638782

RESUMO

Walnut anthracnose caused by Colletotrichum gloeosporioides is a deleterious disease that severely affects the production of walnut (Juglans regia L.). The aim of this study was to assess the antifungal and growth promotion activities of Bacillus velezensis CE 100 as an alternative to chemical use in walnut production. The crude enzyme from B. velezensis CE 100 exhibited chitinase, protease, and ß-l,3-glucanase activity and degraded the cell wall of C. gloeosporioides, causing the inhibition of spore germination and mycelial growth by 99.3% and 33.6% at 100 µL/mL, respectively. The field application of B. velezensis CE 100 culture broth resulted in a 1.3-fold and 6.9-fold decrease in anthracnose disease severity compared to the conventional and control groups, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (up to 1.4 µg/mL) and exhibited the potential for ammonium production and phosphate solubilization to enhance the availability of essential nutrients. Thus, field inoculation of B. velezensis CE 100 improved walnut root development, increased nutrient uptake, enhanced chlorophyll content, and consequently improved total biomass by 1.5-fold and 2.0-fold compared to the conventional and control groups, respectively. These results demonstrate that B. velezensis CE 100 is an effective biocontrol agent against anthracnose disease and a potential plant growth-promoting bacteria in walnut tree production.


Assuntos
Antifúngicos , Bacillus/química , Colletotrichum/crescimento & desenvolvimento , Misturas Complexas , Juglans , Doenças das Plantas/microbiologia , Raízes de Plantas , Antifúngicos/química , Antifúngicos/farmacologia , Misturas Complexas/química , Misturas Complexas/farmacologia , Juglans/crescimento & desenvolvimento , Juglans/microbiologia , Controle Biológico de Vetores , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia
3.
Molecules ; 26(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34361552

RESUMO

Postharvest pathogens such as C. gloeosporioides (MA), C.oxysporum (ME) and P. steckii (MF) are the causal agents of disease in mangoes. This paper presents an in vitro investigation into the antifungal effect of a chitosan (CTS)/nano-titanium dioxide (TiO2) composite coating against MA, ME and MF. The results indicated that, the rates of MA, ME and MF mortality following the single chitosan treatment were 63.3%, 84.8% and 43.5%, respectively, while the rates of mycelial inhibition were 84.0%, 100% and 25.8%, respectively. However, following the addition of 0.5% nano-TiO2 into the CTS, both the mortality and mycelial inhibition rates for MA and ME reached 100%, and the mortality and mycelial inhibition rate for MF also increased significantly, reaching 75.4% and 57.3%, respectively. In the MA, the dry weight of mycelia after the CTS/0.5% nano-TiO2 treatment decreased by 36.3% in comparison with the untreated group, while the conductivity value was about 1.7 times that of the untreated group, and the protein dissolution rate and extravasation degree of nucleic acids also increased significantly. Thus, this research revealed the potential of CTS/nano-TiO2 composite coatings in the development of new antimicrobial materials.


Assuntos
Antifúngicos , Quitosana , Colletotrichum/crescimento & desenvolvimento , Nanocompostos , Titânio , Antifúngicos/química , Antifúngicos/farmacologia , Quitosana/química , Quitosana/farmacologia , Mangifera/microbiologia , Nanocompostos/química , Nanocompostos/uso terapêutico , Doenças das Plantas/microbiologia , Titânio/química , Titânio/farmacologia
4.
Int J Mol Sci ; 22(8)2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33919762

RESUMO

The hemibiotrophic ascomycete fungus Colletotrichum gloeosporioides is the causal agent of anthracnose on numerous plants, and it causes considerable economic losses worldwide. Endocytosis is an essential cellular process in eukaryotic cells, but its roles in C. gloeosporioides remain unknown. In our study, we identified an endocytosis-related protein, CgEnd3, and knocked it out via polyethylene glycol (PEG)-mediated protoplast transformation. The lack of CgEnd3 resulted in severe defects in endocytosis. C. gloeosporioides infects its host through a specialized structure called appressorium, and ΔCgEnd3 showed deficient appressorium formation, melanization, turgor pressure accumulation, penetration ability of appressorium, cellophane membrane penetration, and pathogenicity. CgEnd3 also affected oxidant adaptation and the expression of core effectors during the early stage of infection. CgEnd3 contains one EF hand domain and four calcium ion-binding sites, and it is involved in calcium signaling. A lack of CgEnd3 changed the responses to cell-wall integrity agents and fungicide fludioxonil. However, CgEnd3 regulated appressorium formation and endocytosis in a calcium signaling-independent manner. Taken together, these results demonstrate that CgEnd3 plays pleiotropic roles in endocytosis, calcium signaling, cell-wall integrity, appressorium formation, penetration, and pathogenicity in C. gloeosporioides, and it suggests that CgEnd3 or endocytosis-related genes function as promising antifungal targets.


Assuntos
Colletotrichum/patogenicidade , Endocitose , Proteínas Fúngicas/metabolismo , Doenças das Plantas/microbiologia , Populus/microbiologia , Adaptação Fisiológica/efeitos dos fármacos , Antifúngicos/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Celofane , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/metabolismo , Dioxóis/farmacologia , Endocitose/efeitos dos fármacos , Deleção de Genes , Hifas/efeitos dos fármacos , Melaninas/metabolismo , Oxidantes/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/microbiologia , Pressão , Pirróis/farmacologia , Virulência/efeitos dos fármacos
5.
Cells ; 10(2)2021 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672559

RESUMO

(1) Background: This study was aimed at identifying the Colletotrichum species associated with twig and shoot dieback of citrus, a new syndrome occurring in the Mediterranean region and also reported as emerging in California. (2) Methods: Overall, 119 Colletotrichum isolates were characterized. They were recovered from symptomatic trees of sweet orange, mandarin and mandarin-like fruits during a survey of citrus groves in Albania and Sicily (southern Italy). (3) Results: The isolates were grouped into two distinct morphotypes. The grouping of isolates was supported by phylogenetic sequence analysis of two genetic markers, the internal transcribed spacer regions of rDNA (ITS) and ß-tubulin (TUB2). The groups were identified as Colletotrichum gloeosporioides and C. karstii, respectively. The former accounted for more than 91% of isolates, while the latter was retrieved only occasionally in Sicily. Both species induced symptoms on artificially wound inoculated twigs. C. gloeosporioides was more aggressive than of C. karstii. Winds and prolonged drought were the factor predisposing to Colletotrichum twig and shoot dieback. (4) Conclusions: This is the first report of C. gloeosporioides and C. karstii as causal agents of twig and shoot dieback disease in the Mediterranean region and the first report of C. gloeosporioides as a citrus pathogen in Albania.


Assuntos
Citrus/microbiologia , Colletotrichum/fisiologia , Doenças das Plantas/microbiologia , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/isolamento & purificação , DNA Intergênico/genética , Micélio/fisiologia , Necrose , Filogenia , Folhas de Planta/microbiologia
6.
Microbiol Res ; 248: 126748, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33752111

RESUMO

The hemibiotrophic pathogen Colletotrichum gloeosporioides is the causal agent of poplar anthracnose and causes considerable economic losses. This fungus infects its host through a specialized structure called an appressorium. In a previous study, we demonstrated that the mitogen-activated protein kinase (MAPK) CgMk1 plays a critical role in appressorium formation and pathogenicity. In this study, we identified three upstream components of CgMk1, the putative adaptor protein CgSte50, MAPKKK CgSte11, and MAPKK CgSte7, and showed that CgSte50, CgSte11, and CgSte7 positively regulate the phosphorylation of CgMk1. Deletion of CgSte50, CgSte11, and CgSte7 resulted in the loss of appressorium formation, penetration of the cellophane membrane, invasive growth and pathogenicity, similar to the defects observed in the CgMk1 mutant. CgSte50, CgSte11, CgSte7 and CgMk1 were also required for polarity during conidial germination. At the initial stage of appressorium formation, the accumulation of reactive oxygen species (ROS) was altered in the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants compared with that in wild type (WT). Furthermore, the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants manifested pleiotropic defects during vegetative growth; all mutants exhibited albino colonies, and the aerial hyphae had reduced hydrophobicity. In the mutants, autolysis was detected at the colony edge, and septum formation in the hyphae was elevated compared with that in the WT hyphae. Moreover, deletion of CgSte50, CgSte11, CgSte7 and CgMk1 affected vegetative growth under nitrogen-limiting and osmotic stress conditions. CgSte50, CgSte11, and CgSte7 but not CgMk1 were required for the oxidative stress response. Taken together, these results indicate that the CgMk1 MAPK cascade plays vital roles in various important functions in C. gloeosporioides.


Assuntos
Colletotrichum/enzimologia , Colletotrichum/crescimento & desenvolvimento , Proteínas Fúngicas/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Doenças das Plantas/microbiologia , Populus/microbiologia , Colletotrichum/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Hifas/enzimologia , Hifas/genética , Hifas/crescimento & desenvolvimento , Proteínas Quinases Ativadas por Mitógeno/genética , Morfogênese , Espécies Reativas de Oxigênio/metabolismo , Esporos Fúngicos/enzimologia , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento
7.
ACS Appl Mater Interfaces ; 13(7): 9143-9155, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33567821

RESUMO

Pesticide leaching and soil contamination are major issues in the present agriculture formulations. Hence, here 2D graphene oxide in combination with cationic, anionic, or nonionic polymers were tested for runoff resistance and targeted release behavior. Cationic polymer supplemented the binding of rGO on leaf surface by 30% more than control and reduced off-target leaching in soil by 45% more than control. Further, to enhance the fruit rot control caused by Colletotrichum capsici in chili crop, the rGO was decorated with Cu2-xSe nanocrystals, which provided combined disease control with captan. The chitosan coating in the nanocomposite added targeted pH-responsive fungal inhibition behavior and could reduce the C. capsici growth by ∼1/2 times compared to captan control.


Assuntos
Captana/farmacologia , Quitosana/farmacologia , Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Grafite/farmacologia , Doenças das Plantas/prevenção & controle , Captana/química , Quitosana/química , Colletotrichum/crescimento & desenvolvimento , Frutas/química , Fungicidas Industriais/química , Grafite/química , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Nanocompostos/química , Tamanho da Partícula , Propriedades de Superfície
8.
Protein Pept Lett ; 28(8): 929-937, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33511939

RESUMO

BACKGROUND: Resistance Gene Analogues (RGAs) are an important source of disease resistance in crop plants and have been extensively studied for their identification, tagging and mapping of Quantitative Trait Loci (QTLs). Tracking these RGAs in sugarcane can be of great help for the selection and screening of disease resistant clones. OBJECTIVE: In the present study expression of different Resistance Gene Analogues (RGAs) was assessed in indigenous elite sugarcane genotypes which include resistant, highly resistant, susceptible and highly susceptible to disease infestation. METHODS: Total cellular DNA and RNA were isolated from fourteen indigenous elite sugarcane genotypes. PCR, semi-quantitative RT PCR and real time qPCR analyses were performed. The resultant amplicons were sequence characterized, chromosomal localization and phylogenetic analysis were performed. RESULTS: All of the 15 RGA primers resulted in amplification of single or multiple fragments from genomic DNA whereas only five RGA primers resulted in amplification from cDNA. Sequence characterization of amplified fragments revealed 86-99% similarity with disease resistance proteins indicating their potential role in disease resistance response. Phylogenetic analysis also validated these findings. Further, expression of RGA-012, RGA-087, RGA-118, RGA-533 and RGA-542 appeared to be upregulated and down regulated in disease resistant and susceptible genotypes, respectively, after inoculation with Colletotrichum falcatum. CONCLUSION: RGAs are present in most of our indigenous genotypes. Anyhow, differential expression of five RGAs indicated that they have some critical role in disease resistance. So, the retrieved results can not only be employed to devise molecular markers for the screening of disease resistant genotypes but can also be used to develop disease resistant plants through transgenic technology.


Assuntos
Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Genótipo , Doenças das Plantas/genética , Locos de Características Quantitativas , Saccharum/genética , Colletotrichum/crescimento & desenvolvimento , DNA de Plantas/genética , DNA de Plantas/metabolismo , Doenças das Plantas/microbiologia , RNA de Plantas/biossíntese , RNA de Plantas/genética , Saccharum/microbiologia
9.
Protein Pept Lett ; 28(2): 149-163, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32552632

RESUMO

BACKGROUND: Antimicrobial peptides (AMPs) are found in the defense system in virtually all life forms, being present in many, if not all, plant species. OBJECTIVE: The present work evaluated the antimicrobial, enzymatic activity and mechanism of action of the PEF2 fraction from Capsicum chinense Jack. seeds against phytopathogenic fungi. METHODS: Peptides were extracted from C. chinense seeds and subjected to reverse-phase chromatography on an HPLC system using a C18 column coupled to a C8 guard column, then the obtained PEF2 fraction was rechromatographed using a C2/C18 column. Two fractions, named PEF2A and PEF2B, were obtained. The fractions were tested for antimicrobial activity on Colletotrichum gloeosporioides, Colletotrichum lindemuthianum, Fusarium oxysporum and Fusarium solani. Trypsin inhibition assays, reverse zymographic detection of protease inhibition and α-amylase activity assays were also performed. The mechanism of action by which PEF2 acts on filamentous fungi was studied through analysis of membrane permeability and production of reactive oxygen species (ROS). Additionally, we investigated mitochondrial functionality and caspase activation in fungal cells. RESULTS: It is possible to observe that PEF2 significantly inhibited trypsin activity and T. molitor larval α-amylase activity. The PEF2 fraction was able to inhibit the growth of C. gloeosporioides, C. lindemuthianum and F. oxysporum. PEF2A inhibited the growth of C. lindemuthianum (75%) and F. solani (43%). PEF2B inhibited C. lindemuthianum growth (66%) and F. solani (94%). PEF2 permeabilized F. solani cell membranes and induced ROS in F. oxysporum and F. solani. PEF2 could dissipate mitochondrial membrane potential but did not cause the activation of caspases in all studied fungi. CONCLUSION: The results may contribute to the biotechnological application of these AMPs in the control of pathogenic microorganisms in plants of agronomic importance.


Assuntos
Antifúngicos/farmacologia , Capsicum/química , Colletotrichum/crescimento & desenvolvimento , Fusarium/crescimento & desenvolvimento , Inibidores de Proteases/farmacologia , Sementes/química , Sequência de Aminoácidos , Permeabilidade da Membrana Celular , Colletotrichum/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
10.
Braz. arch. biol. technol ; 64(spe): e21200816, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1285566

RESUMO

Abstract The objective of this work was to evaluate the fungitoxic effect of the aqueous extracts of Baccharis trimera on the mycelial growth of Colletotrichum lindemuthianum 89 race, as well as its effect on the accumulation of phaseolin in hypocotyls of different cultivars and common bean varieties. It was obtained 20% aqueous extract from plants collected in municipalities of the Western Region of Paraná. Blocks containing C. lindemuthianum mycelium were transferred to Petri dishes containing medium with the different extracts and incubated at 25 °C. The colonies diameter was measured until the 12th day. Effects of aqueous extracts on phaseolin production was evaluated in hypocotyls of Carioca, Cnpf 8104, Soberana, Tibatã, Uirapurú cultivars, as well as Rosinha and Vermelho varieties. Each one cultivar and variety hypocotyl was transferred separately to test tubes containing 500 μL of 20% aqueous extracts. Sterile water, Bion®, and UV was used as controls. The phaseolin production was measured in spectrophotometer [280 nm]. Results of the evaluation of the antifungal activity of aqueous extracts of Baccharis sp. specimens collected indicate that approximately 50% of the samples presented capacity to reduce between 74 and 92% of C. lindemuthianum growth. Cultivar Tibatã and Vermelho variety showed greater sensitivity over the applied treatments. Results of fungal filtrates and vegetal aqueous extracts presented a low capacity to induce the production of phaseolin in hypocotyls.


Assuntos
Controle Biológico de Vetores , Colletotrichum/crescimento & desenvolvimento , Phaseolus , Baccharis/microbiologia , Brasil
11.
J Agric Food Chem ; 68(52): 15460-15467, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-33320657

RESUMO

The anthracnose rot of postharvest mango fruit is a devastating fungal disease often resulting in tremendous quality deterioration and postharvest losses. Nitric oxide (NO), as an important signaling molecule, is involved in the responses to postharvest fruit diseases. In the present study, the effectiveness of NO donor sodium nitroprusside (SNP) to prevent anthracnose of "Tainong" mango fruit caused by Colletotrichum gloeosporioides was evaluated through in vivo and in vitro tests. Results from in vivo test showed that SNP treatment effectively inhibited the lesion diameter and disease incidence on inoculated mango fruit during storage. SNP treatment could regulate hydrogen peroxide levels by reinforcing the activities of catalase, peroxidase, superoxide dismutase, and ascorbate peroxidase. Furthermore, SNP elevated the accumulation of lignin, total phenolics, anthocyanin, and flavonoids and the activities of chitinase and ß-1,3-glucanase. In addition, in vitro tests indicated that SNP markedly suppressed mycelial growth and spore germination of C. gloeosporioides through damaging plasma membrane integrity and increasing the leakage of soluble sugar and protein. Our results suggested that SNP could suppress anthracnose decay in postharvest mango fruit, possibly by directly suppressing pathogen growth and indirectly triggering host defense responses.


Assuntos
Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Frutas/efeitos dos fármacos , Mangifera/microbiologia , Nitroprussiato/farmacologia , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Conservação de Alimentos/instrumentação , Frutas/microbiologia , Fungicidas Industriais/farmacologia , Mangifera/efeitos dos fármacos , Óxido Nítrico/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
12.
Int J Mol Sci ; 21(22)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33228091

RESUMO

Endophytic bacteria hold tremendous potential for use as biocontrol agents. Our study aimed to investigate the biocontrol activity of Pseudomonas fluorescens BRZ63, a new endophyte of oilseed rape (Brassica napus L.) against Rhizoctonia solani W70, Colletotrichum dematium K, Sclerotinia sclerotiorum K2291, and Fusarium avenaceum. In addition, features crucial for biocontrol, plant growth promotion, and colonization were assessed and linked with the genome sequences. The in vitro tests showed that BRZ63 significantly inhibited the mycelium growth of all tested pathogens and stimulated germination and growth of oilseed rape seedlings treated with fungal pathogens. The BRZ63 strain can benefit plants by producing biosurfactants, siderophores, indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and ammonia as well as phosphate solubilization. The abilities of exopolysaccharide production, autoaggregation, and biofilm formation additionally underline its potential to plant colonization and hence biocontrol. The effective colonization properties of the BRZ63 strain were confirmed by microscopy observations of EGFP-expressing cells colonizing the root surface and epidermal cells of Arabidopsis thaliana Col-0. Genome mining identified many genes related to the biocontrol process, such as transporters, siderophores, and other secondary metabolites. All analyses revealed that the BRZ63 strain is an excellent endophytic candidate for biocontrol of various plant pathogens and plant growth promotion.


Assuntos
Agentes de Controle Biológico/química , Brassica napus/microbiologia , Endófitos/genética , Genoma Bacteriano , Doenças das Plantas/prevenção & controle , Pseudomonas fluorescens/genética , Amônia/metabolismo , Amônia/farmacologia , Arabidopsis/microbiologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/patogenicidade , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Agentes de Controle Biológico/metabolismo , Carbono-Carbono Liases/biossíntese , Carbono-Carbono Liases/farmacologia , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/patogenicidade , Mineração de Dados/métodos , Endófitos/metabolismo , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Fusarium/patogenicidade , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Filogenia , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/farmacologia , Pseudomonas fluorescens/classificação , Pseudomonas fluorescens/metabolismo , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/crescimento & desenvolvimento , Rhizoctonia/patogenicidade , Plântula/microbiologia , Sideróforos/biossíntese , Sideróforos/farmacologia , Tensoativos/metabolismo , Tensoativos/farmacologia
13.
Antonie Van Leeuwenhoek ; 113(11): 1573-1585, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32815093

RESUMO

Colletotrichum gloeosporioides is a main cause of rubber anthracnose, which results in a huge loss for the natural rubber industry. In this study, an actinomycete strain QY-3 was isolated and had good antagonistic activity against C. gloeosporioides with an inhibition rate of 86.6%. Strain QY-3 was identified as Streptomyces deccanensis preliminarily. Millet medium was selected as the optimal fermentation broth for antifungal metabolites production by S. deccanensis QY-3. The culture filtrate extract (CFE) from the millet broth of S. deccanensis QY-3 exhibits broad-spectrum antifungal activity against plant pathogenic fungi, and its EC50 inhibiting the mycelial growth of C. gloeosporioides is 6.3 µg/mL. The CFE has good thermal and pH stabilities, and it can break the hyphae and inhibit the conidial germination of C. gloeosporioides. 100 µg/mL of CFE had an obvious control effect on rubber anthracnose, and the control efficacy was 63.7% on 5 days after inoculation. Two compounds with inhibitory effects on C. gloeosporioides, anthranilic acid and sangivamycin, were isolated from the CFE. The MICs of both compounds against C. gloeosporioides were 29.3 and 23.0 µg/mL respectively. In conclusion, the CFE from S. deccanensis QY-3 has great potential to be a promising fungicide for rubber anthracnose.


Assuntos
Colletotrichum/efeitos dos fármacos , Meios de Cultivo Condicionados/química , Meios de Cultivo Condicionados/farmacologia , Doenças das Plantas/microbiologia , Borracha , Streptomyces/química , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/fisiologia , Meios de Cultivo Condicionados/metabolismo , Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Fungicidas Industriais/farmacologia , Streptomyces/metabolismo
14.
Molecules ; 25(15)2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32722108

RESUMO

Loquat fruit is one of the most perishable fruits in China, and has a very limited shelf life because of mechanical injury and microbial decay. Due to an increasing concern about human health and environmental security, antagonistic microorganisms have been a potential alternative for fungicides to control postharvest diseases. In this work, the antifungal effect of volatile organic compounds (VOCs) produced by Bacillus methylotrophicus BCN2 and Bacillus thuringiensis BCN10 against five postharvest pathogens isolated from loquat fruit, Fusarium oxysporum, Botryosphaeria sp., Trichoderma atroviride, Colletotrichum gloeosporioides, and Penicillium expansum were evaluated by in vitro and in vivo experiments. As a result, the VOCs released by BCN2 and BCN10 were able to suppress the mycelial growth of all targeted pathogens according to inhibition ratio in the double petri-dish assay as well as disease incidence and disease diameter on loquat fruits. The main volatile compounds were identified by solid-phase microextraction (SPME)-gas chromatography. These VOCs produced by the two strains played complementary roles in controlling these five molds and enabled loquat fruits to keep fresh for ten days, significantly. This research will provide a theoretic foundation and technical support for exploring the functional components of VOCs applicable in loquat fruit preservation.


Assuntos
Antifúngicos/farmacologia , Bacillus thuringiensis/química , Bacillus/química , Eriobotrya/microbiologia , Compostos Orgânicos Voláteis/farmacologia , Antifúngicos/química , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Cromatografia Gasosa , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Hypocreales/efeitos dos fármacos , Hypocreales/crescimento & desenvolvimento , Penicillium/efeitos dos fármacos , Penicillium/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/química
15.
J Agric Food Chem ; 68(28): 7324-7332, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32530612

RESUMO

Natural products are a source of many novel compounds with biological activity for the discovery of new pesticides and pharmaceuticals. Quinoxaline is a fused N-heterocycle in many natural products and synthetic compounds, and seven novel quinoxaline derivatives were designed and synthesized via three steps. Pesticidal activities of title quinoxaline derivatives were bioassayed. Most of these compounds had herbicidal, fungicidal, and insecticidal activities. The compounds 2-(6-methoxy-2-oxo-3-phenylquinoxalin-1(2H)-yl)acetonitrile (3f) and 1-allyl-6-methoxy-3-phenylquinoxalin-2(1H)-one (3g) were the most active herbicides and fungicides. Mode-of-action studies indicated that 3f is a protoprophyrinogen oxidase-inhibiting herbicide. Compound 3f also possessed broad-spectrum fungicidal activity against the plant pathogen Colletotrichum species. Some of these compounds also had insecticidal activity. Molecular docking and DFT analysis can potentially be used to design more active compounds.


Assuntos
Praguicidas/síntese química , Praguicidas/farmacologia , Quinoxalinas/química , Animais , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Herbicidas/síntese química , Herbicidas/química , Herbicidas/farmacologia , Insetos/efeitos dos fármacos , Insetos/crescimento & desenvolvimento , Inseticidas/síntese química , Inseticidas/química , Inseticidas/farmacologia , Simulação de Acoplamento Molecular , Praguicidas/química , Plantas Daninhas/efeitos dos fármacos , Quinoxalinas/farmacologia , Relação Estrutura-Atividade
16.
Int J Mol Sci ; 21(12)2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32545883

RESUMO

We present a case study report into nutritional competition between Trichoderma spp. isolated from wild raspberries and fungal phytopathogenic isolates (Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.), which infect soft fruit ecological plantations. The competition was evaluated on the basis of nutritional potentiates. Namely, these were consumption and growth, calculated on the basis of substrate utilization located on Biolog® Filamentous Fungi (FF) plates. The niche size, total niche overlap and Trichoderma spp. competitiveness indices along with the occurrence of a stressful metabolic situation towards substrates highlighted the unfolding step-by-step approach. Therefore, the Trichoderma spp. and pathogen niche characteristics were provided. As a result, the substrates in the presence of which Trichoderma spp. nutritionally outcompete pathogens were denoted. These were adonitol, D-arabitol, i-erythritol, glycerol, D-mannitol and D-sorbitol. These substrates may serve as additives in biopreparations of Trichoderma spp. dedicated to plantations contaminated by phytopathogens of the genera Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.


Assuntos
Fungos Mitospóricos/fisiologia , Phytophthora/crescimento & desenvolvimento , Rubus/crescimento & desenvolvimento , Trichoderma/fisiologia , Botrytis/crescimento & desenvolvimento , Colletotrichum/crescimento & desenvolvimento , Eritritol/análise , Frutas/crescimento & desenvolvimento , Frutas/microbiologia , Glicerol/análise , Manitol/análise , Ribitol/análise , Rubus/microbiologia , Saccharomycetales/crescimento & desenvolvimento , Microbiologia do Solo , Sorbitol/análise , Álcoois Açúcares/análise
17.
PLoS One ; 15(5): e0233916, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470037

RESUMO

The olive tree (Olea europaea L.) is the most important oil-producing crop of the Mediterranean basin. However, although plant protection measures are regularly applied, disease outbreaks represent an obstacle towards the further development of the sector. Therefore, there is an urge for the improvement of plant protection strategies based on information acquired by the implementation of advanced methodologies. Recently, heavy fungal infections of olive fruits have been recorded in major olive-producing areas of Greece causing devastating yield losses. Thus, initially, we have undertaken the task to identify their causal agent(s) and assess their pathogenicity and sensitivity to fungicides. The disease was identified as the olive anthracnose, and although Colletotrichum gloeosporioides and Colletotrichum acutatum species complexes are the two major causes, the obtained results confirmed that in Southern Greece the latter is the main causal agent. The obtained isolates were grouped into eight morphotypes based on their phenotypes, which differ in their sensitivities to fungicides and pathogenicity. The triazoles difenoconazole and tebuconazole were more toxic than the strobilurins being tested. Furthermore, a GC/EI/MS metabolomics model was developed for the robust chemotaxonomy of the isolates and the dissection of differences between their endo-metabolomes, which could explain the obtained phenotypes. The corresponding metabolites-biomarkers for the discrimination between morphotypes were discovered, with the most important ones being the amino acids L-tyrosine, L-phenylalanine, and L-proline, the disaccharide α,α-trehalose, and the phytotoxic pathogenesis-related metabolite hydroxyphenylacetate. These metabolites play important roles in fungal metabolism, pathogenesis, and stress responses. The study adds critical information that could be further exploited to combat olive anthracnose through its monitoring and the design of improved, customized plant protection strategies. Also, results suggest the necessity for the comprehensive mapping of the C. acutatum species complex morphotypes in order to avoid issues such as the development of fungicide-resistant genotypes.


Assuntos
Colletotrichum/fisiologia , Olea/microbiologia , Doenças das Plantas/prevenção & controle , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/isolamento & purificação , Flores/microbiologia , Frutas/microbiologia , Fungicidas Industriais/farmacologia , Grécia , Metabolômica , Azeite de Oliva , Folhas de Planta/microbiologia , Especificidade da Espécie , Virulência/efeitos dos fármacos
18.
J Sci Food Agric ; 100(10): 4049-4056, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32338377

RESUMO

BACKGROUND: Avocado is affected by Colletotrichum gloeosporioides causing anthracnose. Antagonistic microorganisms against C. gloeosporioides represent an alternative for biological control. Accordingly, in the present study, we focused on the isolation and characterization of potential antagonist bacteria against a member of the C. gloeosporioides species complex with respect to their possible future application. RESULTS: Samples of avocado rhizospheric soil were aquired from an orchard located in Ocuituco, Morelos, Mexico, aiming to obtain bacterial isolates with potential antifungal activity. From the soil samples, 136 bacteria were isolated and they were then challenged against a member of the C. gloeosporioides species complex; only three bacterial isolates A1, A2 and A3 significantly diminished mycelial fungal growth by 75%, 70% and 60%, respectively. Two of these isolates were identified by 16S rRNA as Bacillus mycoides (A1 and A2) and the third was identified as Bacillus tequilensis (A3). Bacillus mycoides bacterial cell-free supernatant reduced the mycelial growth of a member of the C. gloeosporioides species complex isolated from avocado by 65%, whereas Bacillus tequilensis A3 supernatant did so by 25% after 3 days post inoculation. Bacillus tequilensis mycoides A1 was a producer of proteases, indolacetic acid and siderophores. Preventive treatment using a cell-free supernatant of B. mycoides A1 diminished the severity of anthracnose disease (41.9%) on avocado fruit. CONCLUSION: These results reveal the possibility of using B. mycoides A1 as a potential biological control agent. © 2020 Society of Chemical Industry.


Assuntos
Antibiose , Bacillus/fisiologia , Colletotrichum/crescimento & desenvolvimento , Persea/microbiologia , Doenças das Plantas/microbiologia , Bacillus/genética , Bacillus/isolamento & purificação , Colletotrichum/fisiologia , México , Micélio/crescimento & desenvolvimento , Persea/crescimento & desenvolvimento , Sideróforos/metabolismo , Microbiologia do Solo
19.
Arch Microbiol ; 202(6): 1459-1467, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32189017

RESUMO

Sunflower is one of the most economically important oil crops. Recently, sunflower anthracnose caused by Colletotrichum destructivum was reported and suggested to be a potential threat to the quality of oil and edible seeds derived from sunflower in the field and even on the ornamentals in the residential gardens. Colletotrichum destructivum, as the causal agent of sunflower anthracnose, has been rarely studied. In this study, the vegetative growth and sporulation of this fungal species were investigated by assessing the requirements of nutrition and other environmental conditions, such as temperature, ambient pH, and lightness regime. Additionally, the sensitivity of C. destructivum to several fungicides was assessed. The results will provide a baseline for better understanding of the biology and etiology of C. destructivum. This study will be the first reference for a sustainable management strategy according to the occurrence and prevalence of the sunflower anthracnose.


Assuntos
Colletotrichum/crescimento & desenvolvimento , Fungicidas Industriais/farmacologia , Helianthus/microbiologia , Doenças das Plantas/microbiologia , Esporos Fúngicos/crescimento & desenvolvimento , Colletotrichum/classificação , Colletotrichum/efeitos dos fármacos , Colletotrichum/isolamento & purificação
20.
Molecules ; 25(4)2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32093424

RESUMO

Taiwania flousiana (T. flousiana) Gaussen is a precious wood in the family Taxodiaceae. This study investigated the chemical components of the essential oil from the stem bark of T. flousiana and its algicidal, antifungal, and antioxidant properties. Sixty-nine compounds representing 89.70% of the stem bark essential oil were identified by GC-MS. The essential oil showed strong anti-algae, anti-bacteria, and anti-fungus activities against the tested species, and antioxidant activities. The IC50 values of the essential oil against chlorophyll a, chlorophyll b, and the total chlorophyll of Spirogyra communis (a species of algae), 24-96 h after the treatment, ranged from 31.77 to 84.92 µg/mL, while the IC50 values of butachlor ranged from 40.24 to 58.09 µg/mL. Ultrastructure changes revealed by the transmission electron microscopy indicated that the main algicidal action sites were the chloroplast and cell wall. The essential oil showed antifungal activities on Rhizoctonia solani (EC50 = 287.94 µg/mL) and Colletotrichum gloeosporioiles (EC50 = 378.90 µg/mL). It also showed bactericidal activities on Ralstonia solanacearum and Staphylococcus aureus, with zones of inhibition (ZOIs) being 18.66 and 16.75 mm, respectively at 40 µg/disk. Additionally, the essential oil possessed antioxidant activity estimated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method (IC50 = 33.51 µg/mL; IC50 value of the positive control ascorbic acid was 7.98 µg/mL). Thus, the essential oil of this plant might be used as a possible source of natural bioactive molecules in agrochemical industry as well as in food and cosmetic industries.


Assuntos
Antioxidantes , Cupressaceae/química , Óleos Voláteis , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Colletotrichum/crescimento & desenvolvimento , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Ralstonia solanacearum/crescimento & desenvolvimento , Rhizoctonia/crescimento & desenvolvimento , Spirogyra/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento
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