Bacteriocin production by Pseudomonas syringae PsW-1 in plant tissue

1982 ◽  
Vol 28 (6) ◽  
pp. 600-604 ◽  
Author(s):  
Mary L. Smidt ◽  
Anne K. Vidaver
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Tissue ◽  
Inner Core ◽  
Infected Plant ◽  
Resistant Mutant ◽  
Sensitive Strain ◽  
Bacteriocin Activity ◽  
Outer Sheath ◽  
Red Kidney Bean ◽  
20 Nm

The production and activity of syringacin W-1, a particulate bacteriocin made by Pseudomonas syringae PsW-1, was studied in plant tissue. The bacteriocin is rod shaped, approximately 20 nm wide and 75 nm long, and composed of an outer sheath and inner core. Both the producing strain, PsW-1, and a sensitive strain, 16, grew within red kidney bean stems. Strains PsW-1 and 16, or mutants derived from them, were injected into bean stems singly or in mixtures. All singly inoculated strains grew well. However, when the bacteriocin-producing strain was co-inoculated with the sensitive strain, the latter grew poorly, if at all. This was not due to competition for available nutrients, since the sensitive strain grew as well in the presence of a bacteriocin-nonproducing mutant as it did alone. Also, a bacteriocin-resistant mutant grew as well in the presence of the producing strain as it did alone. Bacteriocin activity and particles were recovered from infected plant tissue.

Isolation and characterization of syringacin W-1, a bacteriocin produced by Pseudomonas syringae pv. syringae

1986 ◽  
Vol 32 (3) ◽  
pp. 231-236 ◽  
Author(s):  
Mary L. Smidt ◽  
Anne K. Vidaver
Keyword(s):  
Pseudomonas Syringae ◽  
Inner Core ◽  
Deae Cellulose ◽  
Sedimentation Coefficient ◽  
Temperature Stability ◽  
Ultrafiltration Rate ◽  
Isolation And Characterization ◽  
Outer Sheath ◽  
Shaped Particle

Syringacin W-1, a bacteriocin produced by Pseudomonas syringae pathovar syringae strain PsW-1, is a 20 × 75 nm rod-shaped particle composed of an inner core and outer sheath. Production of syringacin W-1 in broth was induced with 0.1 μLg/mL mitomycin C. The bacteriocin was purified from culture lysates using ultrafiltration, rate zonal centrifugation in sucrose gradients, and DEAE-cellulose chromatography. Purity was evaluated by subjecting syringacin W-1 preparations to electrophoresis in polyacrylamide gels under nondenaturing and denaturing conditions. The chemical composition was principally protein (67.2%), and also comigrating nonessential carbohydrate (10–35%). The physical properties of purified syringacin W-1 were a sedimentation coefficient of 104 for rod-shaped particles, pH stability of 5.2–8.2, and temperature stability from −20 to 40 °C. The bacteriocin was resistant to proteases and to 12 of 13 surfactants tested.

Freeze-fracture, freeze-etch complementary pairs of virus-infected cells reveal value of etching even when relatively high concentrations of cryoprotectants are used

1978 ◽  
Vol 36 (2) ◽  
pp. 136-137
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Plant Tissue ◽  
Phosphate Buffer ◽  
Infected Plant ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Virus Infected Plant ◽  
Infected Cells ◽  
High Concentrations

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.

scholarly journals Changes in genetic constitution and sterol composition during growth of nystatin-resistant heterokaryons ofNeurospora crassa

1983 ◽  
Vol 42 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Jill E. Ogden ◽  
Morris Grindle
Keyword(s):  
Growth Rates ◽  
Minimal Medium ◽  
Resistant Mutant ◽  
Sterol Composition ◽  
Sensitive Strain ◽  
Genetic Constitution ◽  
Polyene Antibiotic ◽  
Ofneurospora Crassa ◽  
Synthetic Media ◽  
Selection Of

SUMMARYHeterokaryons ofN. crassawere synthesized from homokaryotic strains differing in sterol composition and sensitivity to the polyene antibiotic nystatin. Mycelia of the nystatin-sensitive strainerg-1+contained ergosterol and episterol, and the nystatin-resistant mutanterg-1 contained fecosterol and lichesterol. Mycelia of heterokaryons with different proportions oferg-1+:erg-1 nuclei contained various proportions of the four sterols. Ergosterol was the principal sterol in heterokaryons with more than 5%erg-1+nuclei.Heterokaryons with various proportions oferg-1+:erg-1 nuclei were grown for several weeks along tubes of synthetic media. Growth rates were stable on minimal medium and nutritionally supplemented media but nuclear proportions often fluctuated. Growth rates fell sharply on nystatin-supplemented media and there were adaptive increases in proportions of mutanterg-1 nuclei which resulted in selection of nystatin-resistant homokaryotic mycelia.

Characterization and aggressiveness of take-all root rot pathogens isolated from symptomatic bermudagrass putting greens

2021 ◽  
Author(s):  
Cameron Stephens ◽  
Travis W Gannon ◽  
Marc Cubeta ◽  
Tim L. Sit ◽  
Jim Kerns
Keyword(s):  
Plant Tissue ◽  
Root Rot ◽  
Pathogen Detection ◽  
Infected Plant ◽  
Gaeumannomyces Graminis ◽  
In Planta ◽  
High Resolution Melt ◽  
Putting Greens ◽  
Ultradwarf Bermudagrass ◽  
Take All

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodontis (Cc), and Magnaporthiopsis cynodontis (Mc). Many etiological and epidemiological components of this disease remain unknown. Improving pathogen identification and our understanding of the aggressiveness of these pathogens along with growth at different temperatures will advance our knowledge of disease development to optimize management strategies. Take-all root rot pathogens were isolated from symptomatic bermudagrass root and stolon pieces from 16 different golf courses. Isolates of Gg, Gx, Ggram, Cc, and Mc were used to inoculate ‘Champion’ bermudagrass in an in planta aggressiveness assay. Each pathogen was also evaluated at 10, 15, 20, 25, 30, and 35C to determine growth temperature optima. Infected plant tissue was used to develop a real-time PCR high resolution melt assay for pathogen detection. This assay was able to differentiate each pathogen directly from infected plant tissue using a single primer pair. In general, Ggram, Gg, and Gx were the most aggressive while Cc and Mc exhibited moderate aggressiveness. Pathogens were more aggressive when incubated at 30C compared to 20C. While they grew optimally between 24.4 and 27.8C, pathogens exhibited limited growth at 35C and no growth at 10C. These data provide important information on this disease and its causal agents that may improve take-all root rot management.

scholarly journals Specific and Sensitive Detection of Enterobacter mori Using Reliable RT-PCR

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1070-1074 ◽  
Author(s):  
M. M. Lou ◽  
G. L. Jin ◽  
W. X. Tian ◽  
G. Q. Zhang ◽  
X. Y. Fan ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Infected Plant ◽  
Rpob Gene ◽  
Effective Control ◽  
Bacterial Cells ◽  
Pcr Assay ◽  
Strong Positive Reaction ◽  
Polymerase Chain ◽  
Serious Disease ◽  
Type Strains

Enterobacter mori, the causal agent of bacterial wilt in mulberry, is becoming a serious disease in mulberry orchards in China. Because no effective control strategy has been devised for this disease, the reliable screening of mulberry material for latent infection became necessary. Hence, a fast polymerase chain reaction (PCR) assay for the detection of E. mori was developed in this study. The primers were designed within regions of the RNA polymerase β-subunit (rpoB) gene. The method is fast and simple and showed 100% sensitivity (no false negatives) and 100% specificity (no false positives), which was tested with 4 representative E. mori strains, 9 Enterobacter type strains, 2 strains of the other major mulberry bacterial pathogens (Ralstonia solanacearum and Pseudomonas syringae pv. mori) in China, 7 strains of other plant-associated pathogens, and 50 unidentified epiphytic bacterial isolates from mulberry plants. The real-time PCR assays reliably detected the DNA at at least 10 fg/μl and the bacterial cells at 102 CFU/ml from mulberry shoots and roots suspension. The strong positive reaction in testing of all symptomatic plants (with 100% positive) and parts of asymptomatic latent infected plant samples (with 36.4% positive) provided proof that this method is reliable and sensitive and suitable for screening plant material with latent infections of E. mori.

Electro-Extraction of Viruses from Infected Plant Tissue

1981 ◽  
Vol 11 (3) ◽  
pp. 321-338
Author(s):  
A. Poison ◽  
K. J. van der Merwe
Keyword(s):  
Plant Tissue ◽  
Infected Plant

scholarly journals Antimicrobial and genetic strategies to defend kiwifruit against the bacterial pathogen Pseudomonas syringae pathovar actinidiae (Psa)

2021 ◽  
Author(s):  
◽  
Mathew Ambrose Storey
Keyword(s):  
New Zealand ◽  
Pseudomonas Syringae ◽  
Best Practice ◽  
Gene Knockout ◽  
Virulent Strain ◽  
Antimicrobial Properties ◽  
Bacterial Pathogen ◽  
Resistant Mutant ◽  
Potential Biocontrol Agent ◽  
Near Future

<p>A highly virulent strain of the bacterium Pseudomonas syringae pv. actinidiae (Psa-V), the causative agent of bacterial canker of kiwifruit, is threatening the $1.5 billion New Zealand kiwifruit industry. A strain of Psa-V was first identified in Italy in 2008 and related strain with a similar level of virulence arrived in New Zealand in November 2010. Since then it has been spreading rapidly throughout the country with devastating effects. Currently there is no effective treatment for growers to control Psa-V in their orchards and the potential impact of Psa-V on the New Zealand kiwifruit industry and growers is catastrophic. As part of a collaboration between Seeka Kiwifruit Industries, EastPack NZ, and a group of scientists nationwide (Taskforce Green) this work designed and implemented laboratory tests to quantify the effect of candidate antimicrobial sprays. Novel formulations with strong antimicrobial properties, including silver nanoparticles were also tested. This work was complemented by an investigation into the antibiotic resistance potential of Psa-V. A spontaneous streptomycin resistant mutant of Psa-V was generated and the molecular mechanism of resistance was elucidated. Further, gene knockout strategies aimed at facilitating the study of Psa-V virulence genes and ultimately developing a potential biocontrol agent were tested. Overall, this work together with several recent advances in the field should help advise the kiwifruit industry on best practice around the use of anti-Psa-V agents, and may make it possible to facilitate the generation and testing of candidate biocontrol agents in the near future.</p>

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