• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.292-296
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• 1994

Main tobacco diseases were surveyed on tobacco plants in the northern Kyeongbuk area to evaluate the effectiveness of current disease control techniques from 1993 to 1994. The major disease in seedlings was the anthracnose (Colletotrichum tabacum) but the mosaic (TMV) in adult plants. Wild fire (Psedomonas syringae pv. tabaci) and hollow stalk (Erwinia carotovora subsp. carotovora) were more severe in 1993 than those in 1994 because of more rain. Establishment of drain-outlet at the bottom of the temporary transplanting pot gave a significant reduction in anthracnose severity. Most farmers have ignored the protection effect of using milk during transplanting and the removal of diseased roots from the fields on mosaic (TMV). It was considered that the educating program on disease diagnosis and fungicide application might help farmers for the proper use of chemicals.

• The Plant Pathology Journal
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• v.19 no.1
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• pp.43-45
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• 2003

Soft rot symptom was observed on lily bulb in the fields and at a low temperature storage house from 1999 to 2000 in Korea. The small dark-brown lesion appeared on the bulb, and enlarged and developed into the inner scales of the bulb. The bulb became water soaked and gave out unpleasant odor. Two different pathogenic bacteria were isolated from infected tissues. The causal bacteria were identified as Pectobacterium carotovorum subsp. carotovorum (Erwinia carotovora subsp. carotovora) and Pseudomonas marginalis based on bacteriological characteristics. Pathogenicity of the bacteria was proven by Koch's postulations. This is the first report of bacterial soft rot of lily bulb in Korea caused by the two bacteria.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.61-68
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• 1993

From the early 1,100 to 1,900, ginseng cultivation seemed to be practiced with management of the diseases which were, in general, referred to a "disaster" at that time. Farmers had individually developed their own methods to manage the disaster with a try and error from generations to generations. It was not determined until 1909, however, that plant pathogens as a new concept was involved in the disaster and thirteen ginseng diseases were reported in Korea by Japanese plant pathologists. The intensive researches have been carried out from 1978 when Korea Ginseng and Tobacco Research Institute was established. Among the ginseng diseases reported in ginseng growing countries, Altemaria Panax, Eotrytis sp., Cylindrocarpon destmctans, Colletotrichum gloeosporioides, Erwinia carotovora subsp. carotovora, Pythium app. Phytophthora cactomm, Sclerotinia sp., Sclerotium rolfsii, and root rot caused by nitylenchus destructor have been observed in Korea and the appropriate control methods for the major diseases were developed. However, the other nine diseases reported by former researchers have not been confirmed for their pathogenicities and/or occurrences on ginseng yetinseng yet.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2000.10a
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• pp.51.2-51
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• 2000

• The Plant Pathology Journal
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• v.24 no.2
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• pp.183-190
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• 2008

Plant-cell-wall-degrading enzymes (PCWDEs) of Pectobacterium carotovorum subsp. carotovorum are the key virulence factor in pathogenesis of soft rot disease of vegetables. The production of PCWDEs is controlled in a cell density dependent manner to avoid the premature production of PCWDEs and subsequent activation of plant defense. N-oxoacyl-homoserine lactone (OHL) is essential for quorum sensing in the soft rot pathogen and the expI gene is responsible for OHL production. The ExpI homolog isolated from P. carotovorum subsp. carotovorum SL940 had 94% identity with ExpI of E. carotovora subsp. carotovora scc3193 and 74% identity with Carl of E. carotovora subsp. atroseptica. The transgenic plants that express exp I uner the control of CaMV35S promoter were able to produce diffusible OHL. Transgenic plants producing OHL were very resistant to the infection of P. carotovorum subsp. carotovorum. Since the PR1 gene was strongly induced and NPR1 and NPR4 were induced weakly in transgenic plants compared to the wild type, salicylic acid-dependent pathways is likely involved in the resistance to the soft rot pathogen P. carotovorum subsp. carotovorum in ExpI transgenic plants.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.586-593
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• 2007

Seed coating by a phenazine-producing bacterium, Pseudomonas chlororaphis O6, induced dose-dependent inhibition of germination in wheat and barley seeds, but did not inhibit germination of rice or cucumber seeds. In wheat seedlings grown from inoculated seeds, phenazine production levels near the seed were higher than in the roots. Deletion of the gacS gene reduced transcription from the genes required for phenazine synthesis, the regulatory phzI gene and the biosynthetic phzA gene. The inhibition of seed germination and the induction of systemic disease resistance against a bacterial soft-rot pathogen, Erwinia carotovora subsp. carotovora, were impaired in the gacS and phzA mutants of P chlororaphis O6. Culture filtrates of the gacS and phzA mutants of P. chlororaphis O6 did not inhibit seed germination of wheat, whereas that of the wild-type was inhibitory. Our results showed that the production of phenazines by P. chlororaphis O6 was correlated with reduced germination of barley and wheat seeds, and the level of systemic resistance in tobacco against E. carotovora.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1605-1613
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• 2010

Twenty-nine P. polymyxa strains isolated from rhizospheres of various crops were clustered into five genotypic groups on the basis of BOX-PCR analysis. The characteristics of several plant growth-promoting factors among the isolates revealed the distinct attributes in each allocated group. Under gnotobiotic conditions, inoculation of pepper roots with P. polymyxa isolates significantly increased the biomass in 17 of total 29 treated plants with untreated plants. Experiments on induced systemic resistance (ISR) against bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria in pepper by P. polymyxa strains were conducted and only one isolate (KNUC265) was selected. Further studies into ISR mediation by the KNUC265 strain against the soft-rot pathogen Erwinia carotovora subsp. carotovora in tobacco demonstrated that the tobacco seedlings exposed to either bacterial volatiles or diffusible metabolites exhibited a reduction in disease severity. In conclusion, ISR and plant growth promotion triggered by P. polymyxa isolates were systemically investigated on pepper for the first time. The P. polymyxa KNUC265 strain, which elicited both ISR and plant growth promotion, could be potentially used in improving the yield of pepper and possibly of other crops.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.191-201
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• 2016

BACKGROUND: The aim of this study was to investigate the antimicrobial effects of the ethanol extracts from various medicinal herbs against plant pathogens to understand the possible the crop protection agents.METHODS AND RESULTS: Among the tested medicinal herbs, Zizyphus jujuba ethanol extract had the potent antimicrobial activity against Phytophthora capsici, Erwinia carotovorum subsp. carotovora, Pseudomonas syringae pv. syringae and Ralstonia solanacearum. The major constituents of Z. jujuba were identified to eugenol(40.45%), dodecanoic acid(18.40%), β-caryophyllene (10.05%) and isoeugenol(9.85%) by GC/MS. Eugenol and isoeugenol had strong inhibitory activity on spore germination against P. capsici and growth against E. carotovorum subsp. carotovora, P. syringae pv. syringae and R. solanacearum.CONCLUSION: In this regard, eugenol and isoeugenol were found to be responsible for the antimicrobial activity of Z. jujuba ethanol extract against plant pathogens. In addition, Z. jujuba ethanol extract, eugenol and isoeugenol can be used the potent antimicrobial agents.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.157-163
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• 2020

Calmodulin (CaM) mediates cellular Ca²⁺ signals in the defense responses of plants. We previously reported that GmCaM-4 and 5 are involved in salicylic acid-independent activation of disease resistance responses in soybean (Glycine max). Here, we generated a GmCaM-4 cDNA construct under the control of the cauliflower mosaic virus (CaMV) 35S promoter and transformed this construct into potato (Solanum tuberosum L.). The constitutive over-expression of GmCaM-4 in potato induced high-level expression of pathogenesis-related (PR) genes, such as PR-2, PR-3, PR-5, phenylalanine ammonia-lyase (PAL), and proteinase inhibitorII (pinII). In addition, the transgenic potato plants exhibited enhanced resistance against a bacterial pathogen, Erwinia carotovora ssp. Carotovora (ECC), that causes soft rot disease and showed spontaneous lesion phenotypes on their leaves. These results strongly suggest that a CaM protein in soybean, GmCaM-4, plays an important role in the response of potato plants to pathogen defense signaling.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.62-68
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• 2011

Calmodulin (CaM), a $Ca^{2+}$ binding protein in eukaryotes, mediates cellular $Ca^{2+}$ signals in response to a variety of biotic and abiotic external stimuli. The $Ca^{2+}$-bound CaM transduces signals by modulating the activities of numerous CaM-binding proteins. As a CaM binding protein, AtCBP63 ($\b{A}$rabidopsis thaliana $\b{C}$aM-binding protein $\underline{63}$ kD) has been known to be positively involved in plant defense signaling pathway. To investigate the pathogen resistance function of AtCBP63 in potato, we constructed transgenic potato (Solanum tuberosum L.) plants constitutively overexpressing AtCBP63 under the control of cauliflower mosaic virus (CaMV) 35S promoter. The overexpression of the AtCBP63 in potato plants resulted in the high level induction of pathogenesis-related (PR) genes such as PR-2, PR-3 and PR-5. In addition, the AtCBP63 transgenic potato showed significantly enhanced resistance against a pathogen causing bacterial soft rot, Erwinia carotovora ssp. Carotovora (ECC). These results suggest that a CaM binding protein from Arabidopsis, AtCBP63, plays a positive role in pathogen resistance in potato.