• 식물병연구
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• 제17권2호
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• pp.111-120
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• 2011

A bacterial artificial chromosome library of Pectobacterium carotovorum 35 was constructed to characterize the genome and to sequence its hrp region. The hrp cluster of P. carotovorum 35 consisted of 26 open reading frames in five operons. A promoter-based green fluorescent protein technology was used to identify the genes regulated by the alternative sigma factor, HrpL, in P. carotovorum 35. The majority of the selected clones contained the hrpJ operon promoter sequence, which harbors a hrp box, but no putative hrp boxes were detected within the promoter sequences of two other hrpL-regulated genes encoding for pectate lyase and large repetitive protein. Although the promoters of five other hrp operons also contained hrp boxes, their expression was not HrpL-dependent in the promoter-based selection in E. coli. However, transcriptional analysis showed that expression from all operons harboring hrp boxes, except for the hrpN operon, was reduced significantly in the hrpL mutant. The severity of soft-rot symptoms when the hrpL mutant was applied to the surface of tobacco leaves, mimicking natural infection, was greatly attenuated. These results indicate that the hrpL gene of P. carotovorum 35 may be involved in the development of soft-rot symptoms.

• 원예과학기술지
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• 제30권2호
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• pp.137-143
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• 2012

Chinese cabbage plant was grown hydroponically for 4 weeks in order to examine the temporal relationship of calcium concentration of the nutrient solution with calcium content in the leaf tissue and susceptibility of the tissue to soft rot disease by $Pectobacterium$ $carotovorum$ ssp. $carotovorum$ (Pcc). Calcium concentration from 0.5 to 32.0 mM was maintained for 1 week using Hoagland & Arnon solution. The calcium content of the leaf was proportionally increased to the concentration of the nutrient in the solution (r = 0.912). In contrast, the severity of soft rot symptom in the young leaves was inversely related with the amount of calcium supplied to the nutrient solution (r = 0.899). Water-soluble chitosan, prepared by hollow fiber filtration (> 100 kDa) was applied into the nutrient solution from 0.0 to 5,000 ppm. The chitosan of 10 ppm was the most effective to promote calcium uptake of the leaf, showing 155% of the control. The same chitosan solution prohibited most soft rot development of the leaf by Pcc, exhibiting only 53% of the control. Among different molecular weight fractions, chitosan fraction obtained from 30-100 kDa molecular weight cut-off promoted calcium uptake the most up to 163% of the control, and reduced the development of soft rot disease recording merely 36% of the control of the leaf tissue. The results obtained in the present study suggest that large scale production of water-soluble chitosan with an optimum molecular weight and its commercial application to Chinese cabbage production will be important to improve yield and quality of the crop.

• 한국유기농업학회지
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• 제26권1호
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• pp.129-140
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• 2018

Pectobacterium carotovorum subsp. carotovorum은 배추를 포함한 대부분의 채소작물에 강한 병원성을 나타낸다. 포장 방제 효과 검정을 통하여 배추 무름병 억제인자로 선발된 CAB12243-2 균주는 16S rRNA gene의 염기서열 상동성 분석으로 Bacillus toyonensis로 확인되었다. B. toyonensis CAB12243-2 균주는 무름병균의 펙틴분해 작용을 억제하였고 탄소원으로 glucose와 trehalose를 이용하였다. 또한 이 균주는 '노랑봄' 품종으로 봄배추 재배 시 73%, '불암3호' 품종으로 가을배추 재배 시 68.9%의 포장 방제 효과를 보였다. 이러한 결과로 B. toyonensis CAB12243-2 균주는 채소류의 무름병에 대한 효과적인 생물적 방제제로 활용이 가능한 것을 확인할 수 있었다.

• The Plant Pathology Journal
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• 제16권2호
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• pp.98-104
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• 2000

For the taxonomic evaluaition, 15 strains of the genus Pectobacterium and Erwinia were analyzed for 16S-23S rDNA intergenic spacer regions (ISRs). These species contained two types of ISRs, large and small ISRs. Large ISRs were on the range of 474-569 bp size, and coding transfer $\textrm{RNA}^{11e}$($\textrm{tRNA}^{11e}$) and $\textrm{tRNA}^{Ala}$. Small ISRs were 354-459 bp in length and coding $\textrm{tRNA}^{Glu}$. The sequence variations of two ISRs among species and strains were very high as compared with 16S rRNA gene sequences. By phylogenetic trees on the basis of two ISRs, Pectobacterium ere differentiated into P. carotovorum-P. cactiaidum group and P. chrysanthemi group. However, the taxonomic position of E. cypripedii and E. rhapontici, which were not clear on taxonomic delineation between Pectobacterium and Erwinia, were not clearly resolved on the basis of ISRs.

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.792-802
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• 2009

Antimicrobial peptides (AMPs) are considered to be a promising alternative to conventional antibiotics for future generations. We identified four novel hexapeptides with antimicrobial activity: KCM11 (TWWRWW-$NH_2$), KCM12 (KWRWlW-$NH_2$), KCM21 (KWWWRW-$NH_2$), and KRS22 (WRWFIH-$NH_2$), through positional scanning of a synthetic peptide combinatorial library (PS-SCL). The ability of these peptides to inhibit the growth of a variety of bacteria and unicellular fungi was evaluated. KCM11 and KRS22 preferentially inhibited the normal growth of fungal strains, whereas KCM12 and KCM21 were more active against bacterial strains. Bactericidal activity was addressed in a clear zone assay against phytopathogenic bacteria, including Pectobacterium spp., Xanthomonas spp., Pseudomonas spp., etc. KCM21 showed the highest activity and was effective against a wide range of target organisms. Application of KCM21 with inoculation of Pectobacterium carotovorum subsp. carotovorum on detached cabbage leaves resulted in an immune phenotype or a significant reduction in symptom development, depending on the peptide concentration. Cytotoxicity of the four hexapeptides was evaluated in mouse and human epithelial cell lines using an MTT test. The results revealed a lack of cytotoxic effects.

• Mycobiology
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• 제37권1호
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• pp.48-52
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• 2009

Essential oils are mixtures of volatile, lipophilic compounds originating from plants. Some essential oils have useful biological activities including antimicrobial, spasmolytic, antiplasmodial, and insect-repelling activities. In this study, we tested the antimicrobial activity of essential oil prepared from the aromatic plant, Cymbopogon citrates, against three important plant pathogenic and medical microorganisms, Pectobacterium carotovorum, Colletotrichum gloeosporioides, and Aspergillus niger. It effectively inhibited the growth of the bacterium, Pectobacterium carotovorum, in a dose-dependent fashion, and 0.5% of the oil inhibited the growth of bacteria completely. Similarly, the essential oil inhibited the growth of plant pathogenic fungus, Colletotrichum gloeosporioides, and the addition of 1% of essential oil completely inhibited the growth of fungus even after 5 days of culture. Finally, it effectively inhibited the growth of the medically and industrially important fungal species, Aspergillus spp. These results suggest that the essential oil from Cymbopogon citrates may be an environmentally safe alternative to inhibit antimicrobial agents for various uses.

• 식물병연구
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• 제24권3호
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• pp.193-201
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• 2018

Pactobacterium carotovorum subsp. carotovorum (Pcc)에 의한 무름병은 전세계적으로 문제가 되고 있고 특히 온난 다습한 지역에서 문제가 심각하다. 본 연구는 Pcc에 의해 발생하는 무 무름병에 대한 효율적인 저항성 검정법을 확립하기 위하여 수행되었다. 시판 무 품종 60개의 Pcc에 대한 저항성 정도를 조사하고, 추후 실험을 위해 저항성에 차이를 보이는 6개 품종을 선발하였다. 이들 6개 품종의 접종하는 무의 생육 시기, 접종원 농도, 접종 후 재배 온도 등의 발병 조건에 따른 무름병 발생을 조사하였다. 이들 실험의 결과로부터 무의 무름병에 대한 저항성을 검정하기 위해서는, 무 종자를 파종하고 온실($25^{\circ}C{\pm}5^{\circ}C$)에서 20일 동안 재배한 유묘에 Pcc 균주의 세균현탁액($8{\times}10^5cfu/ml$)을 분무하여 접종하고, 접종한 식물은 $25^{\circ}C$ 습실상에 24시간 동안 배양한 후에 $25^{\circ}C$, 상대습도 80%의 생육상으로 이동하여 재배하는 것을 제안하고자 한다.

• 식물병연구
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• 제16권3호
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• pp.312-315
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• 2010

본 연구는 애기장대에서 무름병에 대한 저항성 유전자를 탐색하고자 2만여개의 T-DNA 삽입 돌연변이군을 이용하여 Pcc에 대한 스크리닝을 수행하고 이 방법을 소개한 연구다. 1차 선발을 통하여 15개의 저항성 line과 20개의 감수성 line을 선발하였으며, 이로부터 2차 선발하여 3개의 저항성 line과 4개의 감수성 line을 선발하였고, 최종적으로 3차 선발을 통하여 1개의 감수성 line (Atstp1)을 선발할 수 있었다. 현재 Atstp1을 이용해 flanking sequencing 하여 유전자를 탐색하고 있으며, 앞으로 클로닝을 통하여 다양한 무름병 저항성 식물 개발에 유용하게 이용될 것으로 기대한다.

• The Plant Pathology Journal
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• 제38권6호
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• pp.656-664
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• 2022

Pectobacterium odoriferum is the primary causative agent in Kimchi cabbage soft-rot diseases. The pathogenic bacteria Pectobacterium genera are responsible for significant yield losses in crops. However, P. odoriferum shares a vast range of hosts with P. carotovorum, P. versatile, and P. brasiliense, and has similar biochemical, phenotypic, and genetic characteristics to these species. Therefore, it is essential to develop a P. odoriferumspecific diagnostic method for soft-rot disease because of the complicated diagnostic process and management as described above. Therefore, in this study, to select P. odoriferum-specific genes, species-specific genes were selected using the data of the P. odoriferum JK2.1 whole genome and similar bacterial species registered with NCBI. Thereafter, the specificity of the selected gene was tested through blast analysis. We identified novel species-specific genes to detect and quantify targeted P. odoriferum and designed specific primer sets targeting HAD family hydrolases. It was confirmed that the selected primer set formed a specific amplicon of 360 bp only in the DNA of P. odoriferum using 29 Pectobacterium species and related species. Furthermore, the population density of P. odoriferum can be estimated without genomic DNA extraction through SYBR Green-based real-time quantitative PCR using a primer set in plants. As a result, the newly developed diagnostic method enables rapid and accurate diagnosis and continuous monitoring of soft-rot disease in Kimchi cabbage without additional procedures from the plant tissue.

• 농약과학회지
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• 제13권4호
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• pp.325-331
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• 2009

세 종류의 유용세균, Lactobacillus KLF01, Lactococcus KLC02 그리고 Paenibacillus KPB3는 무름병원세균 Pectobacterium carotovorum subsp. carotovorum (Pcc)에 대한 기내 길항효과를 나타내었으며, 온실 내 포트에서 배추 무름병에 대한 생물적 방제 효과를 병원균 접종 4, 8, 12일 후 각각 조사한 결과 KLC02 균주는 64%, 50%, 56%, KPB3 균주는 66%, 57%, 58%로 나타났다. 반면, KLF01 균주는 KLC02 및 KPB3 균주에 비해 그 효과가 다소 낮았으나 유의성이 인정될 수 있는 방제효과로 조사되었다. 또한 재배포장에서 배추 무름병에 대한 생물적 방제효과는 KLF01, KLC02 및 KPB3 모두 각각 55%, 60% 그리고 62%로 매우 효과적임을 알 수 있었다. 따라서 세 종류의 유용세균 Lactobacillus KLF01, Lactococcus KLC02 그리고 Paenibacillus KPB3 균주를 이용하여 배추 무름병을 억제하기 위한 생물적 방제제로 활용할 수 있음을 보고한다.