• 식물병과 농업
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• 제5권2호
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• pp.105-110
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• 1999

Bacterial leaf spot by Xanthomonas campestris pv. vesicatoria has been known to cause serious problem in red pepper in Korea. However recent survey showed that most smptoms in the leaves were mixed with two different symptoms one was leaf spot and the other was canker. bacteria isolated from canker were identified as Clavibacter michiganensis subsp. michiganensis on the basis of biochemical and physiological characteristics. The causal bacteria were non-motile rod-shaped and Gram-positive. The lesions on pepper leaves appeared at first as small blisters or pimple-like white spots which enlarged in size at a later stage. The centers of some of the spots became necrotic and brown and were surrounded by a white halo. Pathogenicity tests were performed on pepper cv. Alchan seedling by spraying of bacterial suspension. During 1997 and 1998 total 17% of 527 fields surveyed were infected by C. michiganensis subsp. michiganensis. The canker of red pepper caused by C. michiganensis subsp. michiganensis was first identified in this study in Korea, and new name "gueyangbyung" was tentatively given to the disease.

• The Plant Pathology Journal
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• 제36권5호
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• pp.450-458
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• 2020

Pepper and tomato plants infected with two Clavibacter species, C. capsici and C. michiganensis have shown different patterns of disease development depending on their virulence. Here, we investigated how pepper and tomato plants respond to infection by the high-virulent or low-virulent Clavibacter strains. For this, we chose two strains of each Clavibacter species to show different virulence level in the host plants. Although low-virulent strains showed less disease symptoms, they grew almost the same level as the high-virulent strains in both plants. To further examine the response of host plants to Clavibacter infection, we analyzed the expression patterns of plant defense-related genes in the leaves inoculated with different strains of C. capsici and C. michiganensis. Pepper plants infected with high-virulent C. capsici strain highly induced the expression of CaPR1, CaDEF, CaPR4b, CaPR10, and CaLOX1 at 5 days after inoculation (dai), but their expression was much less in low-virulent Clavibacter infection. Expression of CaSAR8.2 was induced at 2 dai, regardless of virulence level. Expression of GluA, Pin2, and PR2 in tomato plants infected with high-virulent C. michiganensis were much higher at 5 dai, compared with mock or low-virulent strain. Expression of PR1a, Osmotin-like, Chitinase, and Chitinase class 2 was increased, regardless of virulence level. Expression of LoxA gene was not affected by Clavibacter inoculation. These results suggested that Clavibacter infection promotes induction of certain defense-related genes in host plants and that differential expression of those genes by low-virulent Clavibacter infection might be affected by their endophytic lifestyle in plants.

• 식물병연구
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• 제16권3호
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• pp.290-293
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• 2010

국내에서 Clavibacter michiganensis subsp. michiganensis에 의한 궤양병은 토마토 농가에 심각한 피해를 주고 있다. 이에 병 발생의 감소와 방제를 위해서는 저항성 품종이 최선의 해결책으로 제시되고 있다. 따라서 국내에서 시판되고 있는 완숙토마토 39품종, 방울토마토 20품종, 대목토마토 13품종에 대한 궤양병 저항성 품종을 선별하기 위해 저항성 검정을 실시하였다. 시판되는 72품종 중 선명, 스위트, 다다끼, 아기꼬, 매치, 마그네트, 프렌즈, 그린파워, 품종이 궤양병에 대해 저항성을 나타내었다.

• 식물병연구
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• 제24권4호
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• pp.342-347
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• 2018

Clavibacter michiganensis는 토마토에 궤양병을 일으키는 식물병원성 세균으로 인공배지에서 자라는 속도가 매우 느리기 때문에 감염조직으로부터 병원균을 분리 배양하는 방법을 통해서는 진단하기가 쉽지 않다. 또한 토마토 궤양병균은 식물체 내에서 오랜 잠복기를 거친 후에 병징을 나타내기 때문에 방제하기 어려운 세균병 중에 하나이므로 발병 시 신속한 진단을 통해 빠른 방제가 이루어져야 한다. 본 연구에서는 토마토 궤양병균의 검출을 위한 특이 프라이머를 제작함으로써 감염 식물체의 direct PCR을 통해 토마토 궤양병에 대한 빠르고 정확한 진단이 가능하도록 하였다. 새로 개발된 CmmF와 CmmR 프라이머 세트로 PCR을 수행했을 때, 토마토 궤양병균의 16-23S ribosomal RNA intergenic spacer 영역에서 약 165 bp의 단일 밴드가 특이적으로 증폭되었다. 반면에 토마토 궤양병균과 유연관계에 있는 고추 궤양병균이나 다른 Clavibacter 종 세균에서는 전혀 증폭되지 않는 것을 확인할 수 있었다. 이 방법은 감염 식물체로부터 DNA를 추출하지 않더라도 감염조직의 즙액에서 바로 토마토 궤양병균의 DNA 증폭이 가능하고 총 진단시간을 줄일 수 있다는 이점이 있기 때문에 토마토 궤양병의 진단에 유용하게 사용될 수 있을 것으로 판단된다.

• The Plant Pathology Journal
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• 제30권3호
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• pp.245-253
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• 2014

Antimicrobial peptides (AMPs) are small but effective cationic peptides with variable length. In previous study, four hexapeptides were identified that showed antimicrobial activities against various phytopathogenic bacteria. KCM21, the most effective antimicrobial peptide, was selected for further analysis to understand its modes of action by monitoring inhibitory effects of various cations, time-dependent antimicrobial kinetics, and observing cell disruption by electron microscopy. The effects of KCM21 on Gram-negative strain, Pseudomonas syringae pv. tomato DC3000 and Gram-positive strain, Clavibacter michiganensis subsp. michiganensis were compared. Treatment with divalent cations such as $Ca^{2+}$ and $Mg^{2+}$ inhibited the bactericidal activities of KCM21 significantly against P. syringae pv. tomato DC3000. The bactericidal kinetic study showed that KCM21 killed both bacteria rapidly and the process was faster against C. michiganensis subsp. michiganensis. The electron microscopic analysis revealed that KCM21 induced the formation of micelles and blebs on the surface of P. syringae pv. tomato DC3000 cells, while it caused cell rupture against C. michiganensis subsp. michiganensis cells. The outer membrane alteration and higher sensitivity to $Ca^{2+}$ suggest that KCM21 interact with the outer membrane of P. syringae pv. tomato DC3000 cells during the process of killing, but not with C. michiganensis subsp. michiganensis cells that lack outer membrane. Considering that both strains had similar sensitivity to KCM21 in LB medium, outer membrane could not be the main target of KCM21, instead common compartments such as cytoplasmic membrane or internal macromolecules might be a possible target(s) of KCM21.

• The Plant Pathology Journal
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• 제31권2호
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• pp.123-131
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• 2015

Clavibacter michiganensis subsp. sepedonicus (Cms) multiplies very rapidly, passing through the vascular strands and into the stems and petioles of a diseased potato. Therefore, the rapid and specific detection of this pathogen is highly important for the effective control of the pathogen. Although several PCR assays have been developed for detection, they cannot afford specific detection of Cms. Therefore, in this study, a computational genome analysis was performed to compare the sequenced genomes of the C. michiganensis subspecies and to identify an appropriate gene for the development of a subspecies-specific PCR primer set (Cms89F/R). The specificity of the primer set based on the putative phage-related protein was evaluated using genomic DNA from seven isolates of Cms and 27 other reference strains. The Cms89F/R primer set was more specific and sensitive than the existing assays in detecting Cms in in vitro using Cms cells and its genomic DNA. This assay was also able to detect at least $1.47{\times}10^2copies/{\mu}l$ of cloned-amplified target DNA, 5 fg of DNA using genomic DNA or $10^{-6}$ dilution point of 0.12 at $OD_{600}$ units of cells per reaction using a calibrated cell suspension.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.569-570
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• 2021

수경 재배는 고품질의 녹색 식물 생산에 상당한 관심을 가지고 있다. 그러나 수경 재배에서 식재 운영 체제를 구축하면 순환하는 배양액 전체에 유해한 박테리아가 번식하는 등 만성적인 문제가 발생할 수 있다. 배양액 오염을 방지하기 위해 자외선 살균 시스템을 사용하는 것에 대한 광범위한 연구가 수행되었다. 이 연구에서 제안 된 모듈은 270 ~ 285nm 파장을 방출하는 UV-C LED를 사용하여 센서 및 컨트롤러와 함께 설계되었다. 모듈은 대장균, Clavibacter michiganensis, Pseudomonas cichorii 및 Fusarium oxysporum을 제거하는 능력을 조사하기 위해 다른 배양액 유속에 대해 300, 500 및 700mW를 방출하도록 설정되었다.

• 식물병연구
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• 제29권2호
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• pp.168-173
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• 2023

본 연구에서는 시중에 판매되고 있는 3종의 농용 항생제를 대상으로 Pectobacterium carotovorum, Pseudomonas syringae pv. actinidiae, Clavibacter michiganensis subsp. michiganensis, C. michiganensis subsp. capsici 및 Xanthomonas arboricola pv. pruni를 포함하는 식물병원세균 91 균주에 대한 저항성을 평가하였으며 다양한 농도의 발리다마이신에이 단독성분에 의한 흡광도 측정을 통해 분광학적으로 균주 생장을 확인하였다. 주성분으로 옥시테트라사이클린과 스트렙토마이신이 합제된 농용 항생제의 경우 안전사용기준 농도의 100배에서도 모든 균주가 생장하지 않았다. 그러나 스트렙토마이신이 주성분인 농용 항생제의 경우 안전사용농도와 그 10배의 농도에서 91개 균주 중 각각 4%와 2%에서 생장하는 것으로 나타났다. 또한 발리다마이신에이의 경우에는 안전사용농도와 그 10배, 100배의 농도에서 각각 97%, 93%, 73%의 균주가 저항성을 가지는 것으로 확인되었으며 그 중에서도 특히 P. carotovorum이 발리다마이신에이에 가장 높은 저항성을 가지는 것으로 나타났다. 발리다마이신에이 단독성분을 통한 저항성을 확인한 결과, 농용 항생제 발리다마이신에이에 저항성을 가지는 균주와 가지지 않는 균주 간의 경향성은 보이지 않는 것으로 나타났다. 그러므로, 식물병원세균에서 항생제 저항성 발달을 이해하기 위한 추가적인 연구가 필요할 것으로 생각된다.

• The Plant Pathology Journal
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• 제34권2호
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• pp.104-112
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• 2018

Accurate and rapid detection of bacterial plant pathogen is the first step toward disease management and prevention of pathogen spread. Bacterial plant pathogens Clavibacter michiganensis subsp. nebraskensis (Cmn), Pantoea stewartii subsp. stewartii (Pss), and Rathayibacter tritici (Rt) cause Goss's bacterial wilt and blight of maize, Stewart's wilt of maize and spike blight of wheat and barley, respectively. The bacterial diseases are not globally distributed and not present in Korea. This study adopted comparative genomics approach and aimed to develop specific primer pairs to detect these three bacterial pathogens. Genome comparison among target pathogens and their closely related bacterial species generated 15-20 candidate primer pairs per bacterial pathogen. The primer pairs were assessed by a conventional PCR for specificity against 33 species of Clavibacter, Pantoea, Rathayibacter, Pectobacterium, Curtobacterium. The investigation for specificity and sensitivity of the primer pairs allowed final selection of one or two primer pairs per bacterial pathogens. In our assay condition, a detection limit of Pss and Cmn was $2pg/{\mu}l$ of genomic DNA per PCR reaction, while the detection limit for Rt primers was higher. The selected primers could also detect bacterial cells up to $8.8{\times}10^3cfu$ to $7.84{\times}10^4cfu$ per gram of grain seeds artificially infected with corresponding bacterial pathogens. The primer pairs and PCR assay developed in this study provide an accurate and rapid detection method for three bacterial pathogens of grains, which can be used to investigate bacteria contamination in grain seeds and to ultimately prevent pathogen dissemination over countries.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.66.1-66.1
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• 2008