Nectar- and stigma exudate-specific expression of an acidic chitinase could partially protect certain apple cultivars against fire blight disease

Abstract Main conclusion Certain apple cultivars accumulate to high levels in their nectar and stigma exudate an acidic chitinase III protein that can protect against pathogens including fire blight disease causing Erwinia amylovora. Abstract To prevent microbial infections, flower nectars and stigma exudates contain various antimicrobial compounds. Erwinia amylovora, the causing bacterium of the devastating fire blight apple disease, is the model pathogen that multiplies in flower secretions and infects through the nectaries. Although Erwinia-resistant apples are not available, certain cultivars are tolerant. It was reported that in flower infection assay, the ‘Freedom’ cultivar was Erwinia tolerant, while the ‘Jonagold’ cultivar was susceptible. We hypothesized that differences in the nectar protein compositions lead to different susceptibility. Indeed, we found that an acidic chitinase III protein (Machi3-1) selectively accumulates to very high levels in the nectar and the stigma exudate of the ‘Freedom’ cultivar. We show that three different Machi3-1 alleles exist in apple cultivars and that only the 5B-Machi3-1 allele expresses the Machi3-1 protein in the nectar and the stigma exudate. We demonstrate that the 5B-Machi3-1 allele was introgressed from the Malus floribunda 821 clone into different apple cultivars including the ‘Freedom’. Our data suggest that MYB-binding site containing repeats of the 5B-Machi3-1 promoter is responsible for the strong nectar- and stigma exudate-specific expression. As we found that in vitro, the Machi3-1 protein impairs growth and biofilm formation of Erwinia at physiological concentration, we propose that the Machi3-1 protein could partially protect 5B-Machi3-1 allele containing cultivars against Erwinia by inhibiting the multiplication and biofilm formation of the pathogen in the stigma exudate and in the nectar.

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Nectar- and stigma-specific expression of a chitinase could partially protect against fire blight in certain apples

10.1101/606046 ◽

2019 ◽

Author(s):

Anita Kurilla ◽

Timea Toth ◽

Laszlo Dorgai ◽

Zsuzsanna Darula ◽

Tamas Lakatos ◽

...

Keyword(s):

Biofilm Formation ◽

Fire Blight ◽

Erwinia Amylovora ◽

Specific Expression ◽

Physiological Concentration ◽

Apple Cultivars ◽

Nectar Protein ◽

Blight Disease ◽

Stigma Exudate

AbstractTo attract pollinators many angiosperms secrete stigma exudate and nectar in their flowers. As these nutritious fluids are ideal infection points for pathogens, both secretions contain various antimicrobial compounds. Erwinia amylovora, the causing bacterium of the devastating fire blight apple disease, is the model pathogen that multiplies in flower secretions and infects through the nectaries. Although Erwinia resistant apples are not available, certain cultivars are tolerant. It was reported that in stigma infection assay, the ‘Freedom’ cultivar was Erwinia tolerant while the ‘Jonagold’ was susceptible. We hypothesized that differences in the nectar protein compositions lead to different susceptibility. Indeed we found that an acidic chitinase III protein (Machi3-1) selectively accumulates in the nectar and stigma of the ‘Freedom’ cultivar. We demonstrate that MYB binding site containing repeats of the ‘Freedom’ Machi3-1 promoter are responsible for the strong nectar- and stigma-specific expression. As we found that in vitro the Machi3-1 protein impairs growth and biofilm formation of Erwinia at physiological concentration, we propose that the Machi3-1 contribute to the tolerance by inhibiting Erwinia multiplication in the stigma exudate and in the nectar. We show that the Machi3-1 allele was introgressed from Malus floribunda 821 into different apple cultivars including the ‘Freedom’.HighlightCertain apple cultivars accumulate to high levels in their nectar and stigma an acidic chitinase III protein that can protect against pathogens including fire blight disease causing Erwinia amylovora

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Management of Erwinia amylovora by Potential Bio-Pesticides in vitro and in vivo Conditions

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v8isp1.38-45.3933 ◽

2020 ◽

Vol 8 (sp1) ◽

pp. 38-45

Author(s):

Kubilay Kurtulus Bastas

Keyword(s):

Fire Blight ◽

Erwinia Amylovora ◽

Shoot Length ◽

Absolute Methanol ◽

Diffusion Method ◽

Thymus Vulgaris ◽

Blight Disease ◽

Santa Maria

Erwinia amylovora, the causative agent of fire blight disease, threatens a lot of species of the Rosaceae family. Antibiotics and copper compounds in chemical applications are most frequently are applied, but these can be phytotoxic and cause resistant strains of the pathogen. In our experiments, 20 herbal materials were tested for their antimicrobial effectiveness against the fire blight pathogen in vitro and in planta. The air-dried plants ground into fine powder and extraction was performed at room temperature by maceration with 80% (v/v) methanol/distilled water. The minimum inhibitory concentration values were determined by using disc diffusion method and streptomycin was used as control in all experiments. Antimicrobial activity was evaluated by measuring the inhibition zones in reference to the pathogen. Among the tested plants, Szygium aromaticum, Thymus vulgaris and Rhus cararia showed a good antibacterial activity and they inhibited the growth of E. amylovora with inhibition zone diameter ranging from 21 to 27 mm at 20% (w/v) in absolute methanol compared to streptomycin (31 mm) in vitro conditions. In vivo tests were performed by using highly virulent E. amylovora isolate (Eak24b, 91%) grown on TSA medium and inoculation on young shoots of 3-year-old Gala variety of apple and Santa Maria variety of pear seedlings at 107 CFU ml-1 density of the pathogen. Disease severity (%) was assessed by by proportion of blighted shoot length to the whole shoot length and also efficacy of the extracts was determined by using Abbott formula. The highest efficacy was obtained by S. aromaticum and T. vulgaris extracts of reducing shoot blight of cv. Gala and cv. Santa Maria by 67.81% - 64-12% and 51.50% - 51.04% ratios, respectively. Obtaining results showed that some medicinal and aromatic plant extracts might be used against fire blight disease as potential new generation chemicals on pome fruits within integrated and organic control programs.

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Antagonistic Activity of Bacillus spp. Against Fire Blight Disease In vitro and In planta

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v9isp.2486-2492.4888 ◽

2022 ◽

Vol 9 (sp) ◽

pp. 2486-2492

Author(s):

Haris Butt ◽

Kubilay Kurtulus Bastas

Keyword(s):

Fire Blight ◽

Positive Control ◽

Antagonistic Activity ◽

In Vivo Studies ◽

In Planta ◽

Bacillus Spp ◽

Apple Cultivars ◽

Blight Disease

Fire blight, affecting more than one hundred and thirty species in the Rosaceae, is probably the most destructive disease affecting pear and apple cultivars in many countries. Currently, there are no effective synthetic compounds with systemic properties. Other major problem is the occurrence and spread of strains of Erwinia amylovora with resistance to streptomycin and copper. Taken into consideration the human and environmental health, the use of biocontrol agents either as an alternative or as a supplement within an integrated fire blight management strategy has attracted worldwide attention. In this study, E. amylovora solution of 107 CFU ml-1 was treated with bio-control agents, Bacillus subtilis str. QST 713, B. amyloliquefaciens str. MBI 600 and their mixture (at solution densities of 106, 107 and 108 CFU ml-1 for each one) on Petri dishes, containing King’s B medium and, compared with positive (streptomycin sulphate) and negative (sterile distilled water) controls. In vivo studies were performed on two-year-old apple cv. Gala seedlings grown in 45-cm-diameter pots containing a sterilized mix of soil–sand–peat under controlled greenhouse conditions (85% relative humidity, 25°C temperature and 16h of day light). The plants were irrigated as needed by drip-irrigation and each pot received a mineral solution (NPK: 20–20–20) at 2 g l-1 twice. When plant shoots reached a length of 30-35 cm, bio-control agents, individually and their mixture, were applied to the plants by a hand-sprayer. Obtaining the data, 108 CFU ml-1 of Bacillus spp. suspension mixture showed strongest in vitro antibacterial effect (26mm) among the tested treatments after positive control streptomycin (28.6mm). Parallel to in vitro findings, the mixture was most effective against the pathogen on cv. Gala (66.03%). Findings show that the use of mixture of beneficial microorganisms with individual antagonistic properties against the pathogen can be an effective strategy as a natural alternative to agrochemicals in the scope of good agriculture practices.

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Effectiveness of a Peptide-rich Fraction from Xenorhabdus budapestensis Culture against Fire Blight Disease on Apple Blossoms

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4329997 ◽

2015 ◽

Vol 43 (2) ◽

pp. 547-553 ◽

Cited By ~ 2

Author(s):

Dávid VOZIK ◽

Katalin BÉLAFI-BAKÓ ◽

Mária HEVESI ◽

Erzsébet BÖSZÖRMÉNYI ◽

András FODOR

Keyword(s):

Fire Blight ◽

Erwinia Amylovora ◽

Control Method ◽

Plant Protection ◽

Test Method ◽

In Planta ◽

Phytopathogenic Bacterium ◽

Protection Potential ◽

Blight Disease

Erwinia amylovora is one of the most frequently occurred plant pathogenic bacterium. It causes necrosis and blight symptoms on host plantsand it lead to considerable yield losses throughout the world on apple trees. There is no effective chemical treatment is currently available against fire blight. The purpose of the present study was to search a new, alternative control method. The evaluation of the plant protection potential of an enriched fraction of Xenorhabdus budapestensis cell-free conditioned media was investigated. Purified samples were tested in vitro and in plantaagainst the phytopathogenic bacterium. A reproducible method for isolation of a peptide-rich fraction from Xenorhabdus cell-free conditionedmedia was established. The process resulted in 400 mg of dry sample prepared from three litres of Xenorhabdus cell culture. Significant correlation was found between the concentration of the purified preparation and the induced inactivation zones against Erwinia amylovora Ea1 in agardiffusion test method. The minimum inhibitory concentration and minimum bactericidal concentration of the purified fraction against Ea1strain were 8 ;g/mL and 16 ;g/mL, respectively. In planta experiments were tested on an apple cultivar (‘Watson Jonathan’) susceptible to fireblight. The effective range of concentration was 62-200 μg/mL, while treatment with 300 μg/mL and larger amounts caused necrotic symptomson the petals of flowers. Current study pointed to the effectiveness of the compounds produced by X. budapestensis against fire blight. Thedevelopment of a commercially applicable formulation of these compounds would allow growers to effectively control fire blight in apple and pearorchards.

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In vitro testing of New Zealand manuka oil and Lema oil for inhibition of Erwinia amylovora

New Zealand Plant Protection ◽

10.30843/nzpp.2011.64.5999 ◽

2011 ◽

Vol 64 ◽

pp. 290-290

Author(s):

E.G. Hough ◽

Y. Jia ◽

M.B. Horner

Keyword(s):

New Zealand ◽

Fire Blight ◽

Erwinia Amylovora ◽

Bacterial Suspension ◽

Inhibition Zones ◽

Blight Disease ◽

Small Inhibition ◽

Initial Results ◽

Manuka Oil

Current tools for the control of fire blight disease of apples caused by Erwinia amylovora have limitations including the increasing pressure by markets against the use of streptomycin Coast Manuka and Coast Lema Oil products have been previously shown to provide control against some bacterial fungal and yeast diseases Experiments were carried out to determine whether either of these products provided control against Erwinia amylovora Coast Lema Oil (05 1 2 3 4 w/v) inhibited E amylovora when added to a bacterial suspension Coast Manuka Oil (04 w/v) failed to inhibit E amylovora when added to the bacterial suspension It was also demonstrated that Coast Lema Oil (05 1 2 3 4 w/v) and Coast Manuka Oil (05 1 2 3 4 w/v) inhibited E amylovora replication when added to agar Filter paper discs soaked in Coast Lema Oil (2 3 4 w/v) caused small inhibition zones around the product when placed directly onto E amylovora Coast Manuka Oil (04 w/v) was unsuccessful in causing inhibition zones around the discs when placed directly onto E amylovora These initial results indicate that Lema oil has the potential to control fire blight in pipfruit trees

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Antibacterial Activity of Antagonistic Bacteria and Plant Extract on Erwinia amylovora the Pathogen of Fire Blight Disease in Egypt

International Journal of Phytopathology ◽

10.33687/phytopath.004.02.1187 ◽

2015 ◽

Vol 4 (2) ◽

pp. 73-79 ◽

Cited By ~ 3

Author(s):

Khaled H. Arafat ◽

Shaheen A. Hanan ◽

Abd-El-Aziz M. Rabab

Keyword(s):

Plant Extract ◽

Large Scale ◽

Fire Blight ◽

Erwinia Amylovora ◽

Management Program ◽

Antagonistic Bacteria ◽

Pear Trees ◽

Blight Disease

The blossom blight phase of fire blight disease on pear trees, caused by the bacterium Erwinia amylovora (Burrill), was typically managed by applying the antibiotic, streptomycin sulfate and copper, to trees during blossom. Biological control agents of fire blight can be achieved by applying nonpathogenic bacteria, viz. Bacillus subtilis or Pantoea agglomerans and plant extract, viz. Harmel (Peganum harmala L.) during open flowers as spraying treatments. The objective of this study was to examine the alternative bactericides against bacterium E. amylovora in vitro and in vivo during two seasons (2013-2014) in Al-Gharbia governorate, Egypt. Our results revealed the ability of these antagonistic bacteria and plant extract can decreased fire blight severity on pear trees. Further studies at different locations in Egypt with large scale application would allow us to make stronger recommendations including their ability to prevent disease and used them as main component in integrated pest management program.

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Effect of Erwinia amylovora infection on peroxidase enzyme activity in resistant apple cultivars

International Journal of Horticultural Science ◽

10.31421/ijhs/10/3/485 ◽

2004 ◽

Vol 10 (3) ◽

Author(s):

Kása K. ◽

Hevesi M. ◽

G. Tóth M. ◽

Stefanovits-Bányai É.

Keyword(s):

Enzyme Activity ◽

Fire Blight ◽

Erwinia Amylovora ◽

General Hypothesis ◽

Total Enzyme Activity ◽

Enhanced Resistance ◽

Peroxidase Enzyme ◽

Apple Cultivars ◽

Blight Disease ◽

Total Enzyme

Two apple cultivars that display enhanced resistance to fire blight (causal agent: Erwinia amylovora) were selected. The aim of the present study was to characterize the peroxidase (POD) enzyme activity of `Szemes alma' (a historical cultivar) and MR-03, (a Hungarian multiresistant hybrid of 'Prima') and compare them to susceptible 'Jonathan M 40' and resistant 'Remo' controls. Peroxides enzyme activity during E. amylovora infections was investigated in artificially infected apple shoots. Increases in enzyme activities were observed in a `Jonathan M40' and in 'Remo', MR-03, `Szemes alma' cultivars. There was a consistent relationship between total enzyme activity and fire blight disease severity. High activity of the peroxidase was positively correlated with the degree of resistance to fire blight. A general hypothesis that POD activity is related to fire blight susceptibility/resistance is supported by our results.

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