• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.142-148
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• 2013

Bacterial diseases in soybean are bacterial pustule by Xanthomonas axonopodis pv. glycines, wildfire by Pseudomonas syringae pv. tabaci, bacterial blight by Pseudomonas savastanoi pv. glycines and bacterial brown spot by Pseudomonas syringae pv. syringae in Korea. It is difficult to identify each disease by early symptoms in fields, because the initial symptoms of these diseases are very similar to each other. In this study, we developed multiplex PCR detection method for rapid and accurate diagnosis of bacterial diseases. The glycinecin A of X. axonopodis pv. glycines, the tabtoxin of P. syringae pv. tabaci, the coronatine of P. savastanoi pv. glycines and the syringopeptin of P. syringae pv. syringae have been reported previously. These bacteriocin or phytotoxin producing genes were targeted to design the specific diagnostic primers. The primer pairs for diagnosis of each bacterial diseases were selected without nonspecific reactions. The studies on simultaneous diagnosis method were also conducted with primarily selected 21 primers. As a result, we selected PCR primer sets for multiplex PCR. Sizes of the amplified PCR products using the multiplex PCR primer set consist of 280, 355, 563 and 815 bp, respectively. This multiplex PCR method provides a efficient, sensitive and rapid tool for the diagnosis of the bacterial diseases in soybean.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.11-20
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• 1996

한 쌍의 R16-1과 R23-2R primer를 이용한 PCR에 의해 증폭된 16S와 23S rDNA 사이의 rDNA spacer 부위의 다형성들이 Pseudomonas avenae, P. glumae, P. fuscovaginae, P. syringae pv. syrngae, Xanthomonas oryzae pv. oryzae, X. oryzae, Xanthomonas herbicola 등 벼 종자전염성 51개 균주의 구분을 위하여 적용되었다. 증폭산물은 820∼950bp의 크기였으며, 각각의 종에 특이적이었고 구분이 가능하였다. Pseudomonas species의 증폭산물은 P. avenae는 950bp, P. glumae는 850bp, P. fuscovaginae는 770pb 및 P. syringae pv. syringae는 1,240, 1,100 및 820bp로 특이적이었다. P. avenae와 P. glumae의 국내균주들은 다형성에 있어 종내 변이는 없었다. X. oryzae pv. oryzae의 860bp와 X. oryzae pv. oryzicola의 890, 440 및 370bp의 이차산물에서 Xanthomonas species의 종내에서 균주에 관련없이 단일화된 다형성을 보였다. CXO 211을 제외한 모든 국내 균주는 a형에 속한 반면 하나의 국내 균주를 포함하여 4개 균주는 b형이었다. E. herbicola의 spacer 부위 증폭은 여러 개의 band를 보였으며, 증폭상은 각각 동일하였고, strain간의 종내 변이는 없었다. 본 실험 결과에 의하여 16S와 23S rDNAdp R16-1과 R23-2R primer를 이용하여 PCR 증폭된 spacer 다형성의 구별은 종자전염성 세균의 신속한 구별에 이용될 수 있을것이다.

• The Plant Pathology Journal
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• v.32 no.2
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• pp.162-167
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• 2016

Pseudomonas syringae pv. actinidiae, the causal agent of canker in kiwifruit, can be divided into three biovars (biovars 1, 2, and 3). Strains belonging to biovar 1 produce phaseolotoxin and were isolated in Japan and Italy before 2008. Strains of biovar 2 produce coronatine instead of phaseolotoxin and have been isolated only in Korea. Strains belonging to biovar 3 produce neither phaseolotoxin nor coronatine and are responsible for the global outbreak of bacterial canker of kiwifruit in recent years. The biovar 3-specific primer set was developed in a previous work. In this study, two sets of PCR primers specific to strains of biovars 1 and 2, respectively, were developed based on random amplified polymorphic DNA analyses. Primers PsaJ-F and PsaJ-R produced a 481-bp region with genomic DNA of biovar 1 strains, whereas primers PsaK-F and PsaK-R amplified a 413-bp region present only in the genome of biovar 2 strains.

• The Plant Pathology Journal
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• v.32 no.4
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• pp.363-370
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• 2016

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker disease in kiwifruit. Antibacterial activity of plant essential oils (PEOs) originating from 49 plant species were tested against Psa by a vapor diffusion and a liquid culture assays. The five PEOs from Pimenta racemosa, P. dioica, Melaleuca linariifolia, M. cajuputii, and Cinnamomum cassia efficiently inhibited Psa growth by either assays. Among their major components, estragole, eugenol, and methyl eugenol showed significant antibacterial activity by only the liquid culture assay, while cinnamaldehyde exhibited antibacterial activity by both assays. The minimum inhibitory concentrations (MICs) of estragole and cinnamaldehyde by the liquid culture assay were 1,250 and 2,500 ppm, respectively. The MIC of cinnamaldehyde by the vapor diffusion assay was 5,000 ppm. Based on the formation of clear zones or the decrease of optical density caused by these compounds, they might kill the bacterial cells and this feature might be useful for managing the bacterial canker disease in kiwifruit.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.608-617
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• 2020

The type III secretion system (T3SS) is a key virulence determinant in the infection process of Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Pathogen constructs a type III apparatus to translocate effector proteins into host cells, which have various roles in pathogenesis. 4-Hydroxybenozic acid and vanillic acid were identified from root extract of Sedum middendorffianum to have inhibitory effect on promoter activity of hrpA gene encoding the structural protein of the T3SS apparatus. The phenolic acids at 2.5 mM significantly suppressed the expression of hopP1, hrpA, and hrpL in the hrp/hrc gene cluster without growth retardation of Pst DC3000. Auto-agglutination of Pst DC3000 cells, which is induced by T3SS, was impaired by the treatment of 4-hydroxybenzoic acid and vanillic acid. Additionally, 2.5 mM of each two phenolic acids attenuated disease symptoms including chlorosis surrounding bacterial specks on tomato leaves. Our results suggest that 4-hydroxybenzoic acid and vanillic acid are potential anti-virulence agents suppressing T3SS of Pst DC3000 for the control of bacterial diseases.

• Research in Plant Disease
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• v.23 no.1
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• pp.1-18
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• 2017

Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker, is currently causing severe economic losses to kiwifruit production worldwide. The pathogen has affected green-fleshed kiwifruit cutlivars and yellow-fleshed kiwifruit cultivars since 1988 and 2006 in Korea, respectively. In recent years, the biovar 3 strains of P. syringae pv. actinidiae were introduced through imported contaminated pollens and have rapidly spread to neighboring kiwiruit orchards by secondary infection, leading to outbreaks of bacterial canker and tremendous damages on yellow- and red-fleshed kiwifruit cultivars. In this review, we summarize the various management practices of bacterial canker of kiwifruit such as disease escaping, cultural practices, blocking of dissemination, early diagnosis, eradication of inoculum sources, chemical control, and trunk injection on the basis of our research works and field experiences and important research products conducted during the last three decades in the world. Finally, we propose a manual for the efficient management of the disease that can be practically utilized at the farmers' orchards in order to keep kiwifruit vines healthy in the future.

• Journal of Life Science
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• v.30 no.1
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• pp.1-9
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• 2020

Pseudomonas syringae pv. actinidiae, the causal agent of a bacterial canker disease in kiwifruit, is subdivided into five genetically distinct populations, namely biovars 1, 2, 3, 5, and 6. Of these, strains belonging to biovar 3 are responsible for a pandemic bacterial canker of kiwifruits since 2008. This study aimed to characterize the structure of the biovar 3 population and investigate the origin of biovar 3 strains isolated in Korea. The genetic variability of fifteen biovar 3 strains, thirteen Korean and two Chinese, were evaluated through random amplified polymorphic DNA (RAPD)-PCR. The RAPD results revealed the presence of eight lineages, designated as subgroups I-VIII, across the biovar 3 strains used in this study. As the strains in subgroups II and III from China were not found in the Korean examples, we concluded that six genetically different biovar 3 subgroups (I, IV, V, VI, VII, and VIII) are present in Korea. In PCR analysis using primers specific to the strains of New Zealand and Europe, Korean strains in subgroups V and VI amplified the relevant DNA bands, suggesting that these were introduced from these two origins, respectively. PCR primers specific to subgroup VIII were developed to monitor the spread of the first biovar 3 strain in Korea, and investigations revealed that this strain was not found in Korea after its first occurrence.

• Journal of Life Science
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• v.31 no.1
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• pp.52-58
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• 2021

Pseudomonas syringae pv. actinidiae, which causes bacterial canker in kiwifruit, is divided into five biovars (1, 2, 3, 5, 6) on the basis of genetic characteristics and toxin productivity. Among them, biovar 3 is responsible for the current global outbreak, and has been isolated in Korea since 2011. Biovar 3 strains isolated from Korea are subdivided into six genetically different lineages (subgroup I, IV, V, VI, VII, and VIII) based on random amplified polymorphic DNA (RAPD) analysis. In this work, the subgroup-specific sequence characterized amplified region (SCAR) primers were developed from sequenced differential RAPD bands. Distribution of the subgroups of the biovar 3 strains collected in Korea from 2011-2017 were examined using these subgroup-specific primer sets. Among the 54 strains tested, 35 strains (64.8%) belonged to subgroup V, 9 strains (16.7%) belonged to subgroup IV, 4 strains (7.4%) belonged to subgroup VI, 3 strains (5.6%) belonged to subgroup VII, 2 strains (3.7%) belonged to subgroup VIII, and 1 (1.9%) strain belonged to subgroup I. Strains belonging to subgroups IV, V, and VI were shown to be related to strains isolated from China, New Zealand, and Chile, respectively. The study revealed that the biovar 3 strains in Korea are genetically diverse and are estimated to have been introduced through pollen sourced from foreign countries.

• BMB Reports
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• v.38 no.6
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• pp.748-754
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• 2005

Pseudomonas syringae pv. tomato (Pst) causes a bacterial speck disease in tomato and Arabidopsis. In Chinese cabbage, in which host-pathogen interactions are not well understood, Pst does not cause disease but rather elicits a hypersensitive response. Pst induces localized cell death and $H_2O_2$ accumulation, a typical hypersensitive response, in infiltrated cabbage leaves. Pre-inoculation with Pst was found to induce resistance to Erwinia carotovora subsp. carotovora, a pathogen that causes soft rot disease in Chinese cabbage. An examination of the expression profiles of 12 previously identified Pst-inducible genes revealed that the majority of these genes were activated by salicylic acid or BTH; however, expressions of the genes encoding PR4 and a class IV chitinase were induced by ethephon, an ethylene-releasing compound, but not by salicylic acid, BTH, or methyl jasmonate. This implies that Pst activates both salicylate-dependent and salicylate-independent defense responses in Chinese cabbage.

• Plant Disease and Agriculture
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• v.5 no.2
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• pp.95-99
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• 1999

Chemical control of bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae was attempted by spraying of streptomycin sulfate ·oxytetracycline WP streptomycin WP streptomycin ·copper hydroxide WP kasugamycin SL kasugamycin·copper oxychloride WP and copper hydroxide WP. The control efficacies of the bactericides were variable depending upon the spraying schedule,. Application of streptomycin WP and streptomycin sulfate·oxytetracycline WP from middle April to early May was found to be the most effective in controlling the bacterial canker. For copper hydroxide WP the spraying from middle January to early February showed the highest control efficacy. Kasugamycin SL was the most effective in controlling the disease by spraying from middle April to early May but it was still relatibvely effective during other spray periods. Foliar application of copper hydroxide WP and copper-antibiotic formulaions after middle April caused severe phytotoxicity. Kasgamycil SL streptomycin WP streptomycin·copper hydroxide WP and copper hydroxide WP were potential bactericides which could substitute streptomycin sulfate·oxytetracycline WP. Selective applications of the bactericides according to their optimum spray time can enhance the control efficacies against bacterial canker of kiwifruit and retard the emergency of resistant strains of P. syringae pv. actinidiae to the bactericides. The optimum spray number of streptomycin sulfate·oxytetracycline WP was 3 times with 15-day-intervals or 4 times with 10-day-intervals. The result suggested that the potential bactericides to bacterial canker of kiwifruit should be also used according to their optimum spray schedules in order to get their highest control efficacies.