• The Plant Pathology Journal
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• 제39권1호
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• pp.88-107
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• 2023

In the present investigation, bacterial isolates from infected apple trees causing apple canker during winter were studied in the northern Gyeongbuk Province, Korea. The pathogen was identified as Pseudomonas syringae pv. syringae (Pss) through various physiological and biochemical characterization assays such as BIOLOG, gas chromatography of fatty acid methyl esters, and 16S rRNA. Bioassays for the production of phytotoxins were positive for syringopeptin and syringomycin against Bacillus megaterium and Geotrichum candidum, respectively. The polymerase chain reaction (PCR) method enabled the detection of toxin-producing genes, syrB1, and sypB in Pss. The differentiation of strains was performed using LOPAT and GATTa tests. Pss further exhibited ice nucleation activity (INA) at a temperature of -0.7℃, indicating an INA⁺ bacterium. The ice-nucleating temperature was -4.7℃ for a non-treated control (sterilized distilled water), whereas it was -9.6℃ for an INA^- bacterium Escherichia coli TOP10. These methods detected pathogenic strains from apple orchards. Pss might exist in an apple tree during ice injury, and it secretes a toxin that makes leaves yellow and cause canker symptoms. Until now, Korea has not developed antibiotics targeting Pss. Therefore, it is necessary to develop effective disease control to combat Pss in apple orchards. Pathogenicity test on apple leaves and stems showed canker symptoms. The pathogenic bacterium was re-isolated from symptomatic plant tissue and confirmed as original isolates by 16S rRNA. Repetitive element sequence-based PCR and enterobacterial repetitive intergenic consensus PCR primers revealed different genetic profiles within P. syringae pathovars. High antibiotic susceptibility results showed the misreading of mRNA caused by streptomycin and oxytetracycline.

• 한국작물학회지
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• 제58권2호
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• pp.142-148
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• 2013

국내 콩에서 발생하는 세균병해인 불마름병, 들불병, 세균점무늬병, 세균갈색점무늬병의 다중 진단을 위한 PCR 방법을 요약하면 다음과 같다. 1. 콩에 발생하는 각각의 세균들은 서로 다른 박테리오신(bacteriocin) 이나 파이토톡신(phytotoxin)을 생산하는데 이와 관련한 유전자를 목적으로 하여 진단프라이머를 설계하였다. 2. 불마름병은 glycinecin A, 들불병은 tabtoxin, 세균점무늬병은 coronatine과 세균갈색점무늬병은 syringopeptin을 목적유전자로 하여 다중 진단프라이머 조합을 설계하였다. 3. 1차 선발로 각각의 균주에 대한 단일 진단 프라이머를 선발하였으며, 여기선 선발된 21개의 프라이머들을 조합하여 4종 다중진단프라이머 선발을 위한 2차 선발에 이용하였다. 최종적으로 280 bp의 불마름병, 355 bp의 세균갈색점무늬병, 563 bp의 들불병과 815 bp의 세균점무늬병으로 구성된 다중진단 프라이머 조합이 개발되었다. 4. 선발된 4종 다중 진단 프라이머 조합의 경우 다른 세균들과의 비특이적 반응이 있는지 확인하기 위한 3차 선발을 거쳐 그 특이성을 검증하였다.