scholarly journals Plant Extract Treatments Induce Resistance to Bacterial Spot by Tomato Plants for a Sustainable System

Horticulturae ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 36
Author(s):  
Kamal A. M. Abo-Elyousr ◽  
Najeeb M. Almasoudi ◽  
Ahmed W. M. Abdelmagid ◽  
Sergio R. Roberto ◽  
Khamis Youssef

The aim of this study is to assess the effect of extracts of Nerium oleander, Eucalyptus chamadulonsis and Citrullus colocynthis against bacterial spot disease of tomato and to investigate the induction of resistance by tomato (Solanum lycopersicum) in order to promote a sustainable management system. The antibacterial activity of aqueous and ethanol plant extracts was tested against Xanthomonas axonopodis pv. vesicatoria, isolate PHYXV3, in vitro and in vivo. The highest antibacterial activity in vitro was obtained with C. colocynthis, N. oleander and E. chamadulonsis, respectively. In vivo, ethanol extracts of N. oleander and E. chamadulonsis were more effective than aqueous extracts in reducing pathogen populations on tomato leaves. Under greenhouse conditions, application of the plant extracts at 15% (v/v) to tomato plants significantly reduced disease severity and increased the shoot weight of ‘Super Marmande’ tomato. In most cases, plant extracts significantly increased total phenol and salicylic acid content of tomato plants compared to either healthy or infected ones. In addition, C. colocynthis and E. chamadulonsis extracts significantly increased peroxidase activity while only E. chamadulonsis increased polyphenol oxidase after infection with the causal agent. The results indicated that the plant extracts showed promising antibacterial activity and could be considered an effective tool in integrated management programs for a sustainable system of tomato bacterial spot control.

2012 ◽  
Vol 48 (No. 2) ◽  
pp. 74-79 ◽  
Author(s):  
S.M.A. Nashwa ◽  
K.A.M. Abo-Elyousr

The antimicrobial activity of six plant extracts from Ocimum basilicum (Sweat Basil), Azadirachta indica (Neem), Eucalyptus chamadulonsis (Eucalyptus), Datura stramonium (Jimsonweed), Nerium oleander (Oleander), and Allium sativum (Garlic) was tested for controlling Alternaria solani in vitro and in vivo. In in vitro study the leaf extracts of D. stramonium, A. indica, and A. sativum at 5% concentration caused the highest reduction of mycelial growth of A. solani (44.4, 43.3 and 42.2%, respectively), while O. basilicum at 1% and 5% concentration and N. oleander at 5% concentration caused the lowest inhibition of mycelial growth of the pathogen. In greenhouse experiments the highest reduction of disease severity was achieved by the extracts of A. sativum at 5% concentration and D. stramonium at 1% and 5% concentration. The greatest reduction of disease severity was achieved by A. sativum at 5% concentration and the smallest reduction was obtained when tomato plants were treated with O. basilicum at 1% and 5% concentration (46.1 and 45.2 %, respectively). D. stramonium and A. sativum at 5% concentration increased the fruit yield by 76.2% and 66.7% compared to the infected control. All treatments with plant extracts significantly reduced the early blight disease as well as increased the yield of tomato compared to the infected control under field conditions.


Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 613
Author(s):  
Alfredo Ambrico ◽  
Mario Trupo ◽  
Rosaria Magarelli ◽  
Roberto Balducchi ◽  
Angelo Ferraro ◽  
...  

Several bacteria pathogens are responsible for plant diseases causing significant economic losses. The antibacterial activity of Dunaliella salina microalgae extracts were investigated in vitro and in vivo. First, biomass composition was chemically characterized and subjected to extraction using polar/non-polar solvents. The highest extraction yield was obtained using chloroform:methanol (1:1 v/v) equal to 170 mg g−1 followed by ethanol (88 mg g−1) and hexane (61 mg g−1). In vitro examination of hexane extracts of Dunaliella salina demonstrated antibacterial activity against all tested bacteria. The hexane extract showed the highest amount of β-carotene with respect to the others, so it was selected for subsequent analyses. In vivo studies were also carried out using hexane extracts of D. salina against Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum on young tomato plants and fruits of tomato and zucchini, respectively. The treated young tomato plants exhibited a reduction of 65.7% incidence and 77.0% severity of bacterial speck spot disease. Similarly, a reduction of soft rot symptoms was observed in treated tomato and zucchini fruits with a disease incidence of 5.3% and 12.6% with respect to 90.6% and 100%, respectively, for the positive control.


2018 ◽  
pp. 31-38

Actividad antibacteriana de extractos vegetales frente a cepas intrahospitalarias, Iquitos-Perú Antibacterial activity of plant extracts against nosocomial strains, Iquitos-Peru Ricardo E. Abadie, Ronald Medina O., Lastenia Ruiz, Alvaro Tresierra-Ayala Laboratorio de Microbiología. Centro de Investigación de Recursos Naturales de la Universidad Nacional de la Amazonía Peruana (CIRNA-UNAP). Psje. Los Paujiles S/N, San Lorenzo, distrito de San Juan Bautista, Iquitos-Perú DOI: https://doi.org/10.33017/RevECIPeru2014.0005/  Resumen La región amazónica es una de las áreas que posee la mayor biodiversidad del mundo, albergando varios miles de especies de plantas, muchas de las cuales son utilizadas por sus pobladores como plantas medicinales. Durante los últimos años, el empleo de estos recursos vegetales o de sus productos viene incrementándose de manera importante, lo cual podría deberse a una serie de factores, entre los que destacan el conocimiento de su composición química, y al hecho que en la actualidad se han realizado numerosos ensayos farmacológicos tanto in vivo como in vitro. La aparición de cepas resistentes a los antibióticos comerciales en los últimos tiempos, está creando la necesidad de buscar otras estrategias o alternativas para controlarlas, tal es el caso del uso de las plantas (medicina tradicional), debido a los principios activos que poseen. Se pretende con este trabajo, determinar probables alternativas para combatir infecciones bacterianas de aquellos agentes drogoresistentes, este problema reviste importancia crítica particular en los países en desarrollo, donde quizás no se dispone de antibióticos de segunda línea más costosos o, si los hay, su precio es inasequible. El estudio se realizó en la ciudad de Iquitos, Provincia de Maynas, Departamento de Loreto. Los ensayos microbiológicos se realizaron en el Laboratorio de Microbiología del Centro de Investigación de Recursos Naturales de la Amazonia (CIRNA) de la Universidad Nacional de la Amazonia  Peruana (UNAP). Se determinó la actividad antibacteriana de 6 extractos vegetales (Alchornea triplinervia, Annona muricata, Averrhoa carambola, Brunfelsia grandiflora, Caraipa grandifolia y Cedrela odorata) mediante la técnica de difusión en disco, y a aquellos que presentaron actividad se les determinó la Concentración Inhibitoria Mínima y la Concentración Bactericida Mínima mediante la técnica de macrodilución en caldo. Ninguno de los extractos tuvieron actividad frente a las cepas de E. coli; cuatro extractos tuvieron actividad frente a las cepas de P. aeruginosa, siendo los extractos de Cedrela odorata y Alchornea triplinervia los que tuvieron mayor actividad frente a esta bacteria, con CIM = 15.62 y 62.5 mg/ml, respectivamente; todos los extractos tuvieron actividad frente a las cepas de S. aureus, siendo los extracto de C. odorata, A. triplinervia y Caraipa grandiflora, los de mayor actividad con una CIM = 3.91 mg/ml para cada uno.  Se obtuvieron prometedores resultados de actividad antibacteriana de los extractos en estudio frente a cepas intrahospitalarias, mayormente contra S. aureus. Descriptores: Actividad antibacteriana, extractos vegetales, cepas intrahospitalarias Abstract The Amazon region is one of the areas with the largest biodiversity in the world, hosting several thousand species of plants, many of which are used by its people as medicinal plants. In recent years, the use of these plant resources or products has been increasing significantly, which could be due to a number of factors, among them the knowledge of their chemical composition, and the fact that at present there have been numerous pharmacological tests both in vivo and in vitro. The emergence of antibiotic-resistant strains in recent years, is creating a need for other strategies or ways to control them, as in the case of the use of plants (traditional medicine), because the active ingredients bearing. This work is intended to determine probable alternatives to combat bacterial infections of those agents antibiotic-resistant, this problem is particularly critical in developing countries, where perhaps there are no antibiotics or expensive second line, if any, price is unavailable. The study was conducted in Iquitos city, Province of Maynas, Department of Loreto. Microbiological tests were performed at Microbiology Laboratory of Research Center of Natural Resources of the Amazon (CIRNA) of the National University of the Peruvian Amazon (UNAP). The antibacterial activity of six plant extracts (Alchornea triplinervia, Annona muricata, Averrhoa carambola, Brunfelsia grandiflora, Caraipa grandifolia y Cedrela odorata) by the disk diffusion method was determined, and those that showed activity were determined Minimum Inhibitory Concentration and Minimum Bactericidal Concentration by macrodilution technique. None of the extracts were active against strains of E. coli; four extracts had activity against strains of P. aeruginosa, with Cedrela odorata and Alchornea triplinervia extracts which had greater activity against these bacteria, with MIC = 15.62 and 62.5 mg/ml, respectively; all extracts were active against strains of S. aureus, with the extract of C. odorata, A. triplinervia and Caraipa grandiflora, the most active with an MIC = 3.91 mg/ml for each. Was obtained Promising results of antibacterial activity of the extracts in study against nosocomial strains, mostly against S. aureus. Keywords: Antibacterial activity, plant extracts, nosocomial strains


Plant Disease ◽  
2016 ◽  
Vol 100 (7) ◽  
pp. 1460-1465 ◽  
Author(s):  
A. Strayer ◽  
I. Ocsoy ◽  
W. Tan ◽  
J. B. Jones ◽  
M. L. Paret

Bacterial spot, caused by four Xanthomonas spp., is one of the most damaging diseases of tomato worldwide. Due to limited disease management options, growers rely heavily on copper-based bactericides, which are often ineffective due to the presence of copper-resistant Xanthomonas strains. This study was undertaken to characterize the antibacterial activity of a silver-based nanocomposite, Ag-dsDNA-GO, and its potential as an alternative to copper. Ag-dsDNA-GO at rates as low as 10 μg/ml killed all bacterial cells of copper-tolerant and -sensitive Xanthomonas perforans strains in suspensions containing approximately 103 CFU/ml within 15 min of exposure in vitro, whereas equivalent rates of copper (10, 25, and 50 μg/ml) were unable to significantly reduce populations compared with the untreated control after 24 h of exposure (P = 0.05). All copper concentrations killed the copper-sensitive X. perforans strain but required exposure for ≥1 h. Ag-dsDNA-GO also exhibited antibacterial activity against copper-tolerant X. vesicatoria, X. euvesicatoria, and X. gardneri strains. In greenhouse studies, tomato plants treated with Ag-dsDNA-GO at either 75 or 100 μg/ml prior to artificial inoculation significantly reduced disease severity when compared with copper-mancozeb and negative controls (P = 0.05). This study highlights the potential of Ag-dsDNA-GO as an alternative to copper in tomato transplant production.


2010 ◽  
Vol 45 (12) ◽  
pp. 1381-1387 ◽  
Author(s):  
Roberto Lanna Filho ◽  
Reginaldo da Silva Romeiro ◽  
Eduardo Alves

The objective of this work was to evaluate in vitro and in vivo biocontrol of bacterial spot (Xanthomonas vesicatoria) and early blight (Alternaria solani) by the epiphytic bacteria Paenibacillus macerans and Bacillus pumilus. Tomato plants were previously sprayed with epiphytic bacteria, benzalkonium chloride and PBS buffer and, after four days, they were inoculated with A. solani and X. vesicatoria. To determine the phytopathogenic bacteria population, leaflet samples were collected from each treatment every 24 hours, for seven days, and plated on semi-selective medium. The effect of epiphytic bacteria over phytopathogens was performed by the antibiosis test and antagonistic activity measured by inhibition zone diameter. The epiphytic and benzalkonium chloride drastically reduced the severity of early blight and bacterial spot in comparison to the control (PBS). In detached leaflets, the epiphytic bacteria reduced in 70% the number of phytopathogenic bacteria cells in the phylloplane. The antibiosis test showed that the epiphytic bacteria efficiently inhibit the phytopathogens growth. In all the bioassays, the epiphytic bacteria protect tomato plants against the phytopathogens


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1503
Author(s):  
Carla Guijarro-Real ◽  
Mariola Plazas ◽  
Adrián Rodríguez-Burruezo ◽  
Jaime Prohens ◽  
Ana Fita

Antiviral treatments inhibiting Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication may represent a strategy complementary to vaccination to fight the ongoing Coronavirus disease 19 (COVID-19) pandemic. Molecules or extracts inhibiting the SARS-CoV-2 chymotripsin-like protease (3CLPro) could contribute to reducing or suppressing SARS-CoV-2 replication. Using a targeted approach, we identified 17 plant products that are included in current and traditional cuisines as promising inhibitors of SARS-CoV-2 3CLPro activity. Methanolic extracts were evaluated in vitro for inhibition of SARS-CoV-2 3CLPro activity using a quenched fluorescence resonance energy transfer (FRET) assay. Extracts from turmeric (Curcuma longa) rhizomes, mustard (Brassica nigra) seeds, and wall rocket (Diplotaxis erucoides subsp. erucoides) at 500 µg mL−1 displayed significant inhibition of the 3CLPro activity, resulting in residual protease activities of 0.0%, 9.4%, and 14.9%, respectively. Using different extract concentrations, an IC50 value of 15.74 µg mL−1 was calculated for turmeric extract. Commercial curcumin inhibited the 3CLPro activity, but did not fully account for the inhibitory effect of turmeric rhizomes extracts, suggesting that other components of the turmeric extract must also play a main role in inhibiting the 3CLPro activity. Sinigrin, a major glucosinolate present in mustard seeds and wall rocket, did not have relevant 3CLPro inhibitory activity; however, its hydrolysis product allyl isothiocyanate had an IC50 value of 41.43 µg mL−1. The current study identifies plant extracts and molecules that can be of interest in the search for treatments against COVID-19, acting as a basis for future chemical, in vivo, and clinical trials.


2021 ◽  
Vol 22 (6) ◽  
pp. 3253
Author(s):  
Clarisse Roblin ◽  
Steve Chiumento ◽  
Cédric Jacqueline ◽  
Eric Pinloche ◽  
Cendrine Nicoletti ◽  
...  

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 285
Author(s):  
Manuela Rodríguez-Romero ◽  
Belén Godoy-Cancho ◽  
Isabel M. Calha ◽  
José António Passarinho ◽  
Ana Cristina Moreira

The ability of three herbaceous plants (Diplotaxis tenuifolia (L.) DC., Eruca vesicaria L. and Raphanus raphanistrum L.) from Iberian wood pastures to reduce Phytophthora cinnamomi Rands pathogen populations through allelopathic relationships is studied. The inhibitory capacity of their aqueous root extracts (AREs) on mycelial growth and production of P. cinnamomi reproductive structures is analysed in vitro. In addition, Quercus seedlings were grown in infested by P. cinnamomi-soils and with the presence or absence of allelopathic and susceptible herb species to the pathogen to assess the defensive chemical response of Quercus seedlings through their leaf phenolic compounds. Results show a strong inhibitory capacity of AREs on P. cinnamomi activity in vitro and a protective effect of these herb species on Quercus plants against P. cinnamomi in vivo. D. tenuifolia would be especially suited for biological control in the pathogen suppression.


Sign in / Sign up

Export Citation Format

Share Document