• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.273-276
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• 2002

Rehmannia glutinosa is one of the most important medicinal crops in Korea. However, various plant pathogens including Fusarium sp. cause great damages and cause enormous economic losses. Therefore, this study was conducted to select Fusarium resistant plants by using mutagen-treated Rehmannia glutinosa. The plant material used was a native accession of Rehmannia glutinosa. As a result, among the Rehmannia glutinosa treated with various concentrations of EMS, R. glutinosa treated with 0. 03M EMS showed higher resistance against infection of F. oxysporum in pot tests, and Rehmannia glutinosa plants treated with 0.12M EMS showed higher resistance against infection of F. oxysporum in field tests.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.40-60
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• 2003

Fruit ripening represents a genetically synchronized system that involves developmental process unique to plant species, The phenomenon of ripening includes changes in color, texture, respiration rate, flavor, and aroma. Ripe fruits generally exhibit increased susceptibility to pathogen infection. However, fruits as a reproductive organ have their own protection mechanism against pathogens to maintain their integrity during seed maturation. In several nonclimacteric fruits, such as cherry, grape, and pepper, that do not have an ethylene burst during ripening, resistance against phytopathogens increases during ripening. Colletotrichum gloeosporioides is a causal agent of anthracnose disease in pepper plants (Capsicum annuum). We have established that C. gloeosporioides has susceptible and resistant interactions with pepper fruits during pre- and post-ripening stages, respectively. And we have interested in looking for a molecular mechanism that would explain the fungal resistance during ripening of nonclimacteric pepper fruit. In this presentation, a molecular characterization of the pepper esterase gene (PepEST) that is highly expressed in the resistant response will be demonstrated as an example of development and industrial applications of versatile-usable genes of plant.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.11-26
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• 1994

Crown gall of stonefruit and nut trees is one of the very few plant diseases subject to efficient biological control. The disease is caused by the soil-inhabiting bacteria Agrobacterium tumefaciens and Agrobacterium rhizogenes and the original control organism was a non-pathogenic isolate of A. rhizogenes strain K84. Control is achieved by dipping planting material in a cell suspension of strain K84 which specifically inhibits pathogenic strains containing a nopaline Ti plasmid. Because the agrocin 84-encoding plasmid (pAgK84) is conjugative, it can be transmitted from the control strain to pathogenic strains which, as a result, become immune to agrocin 84 and cannot be controlled. To prevent this happening, the transfer genes on pAgK84 were located and then largely eliminated by recombinant DNA technology. The resulting construct, strain K1026, is transfer deficient but controls crown gall just as effectively as does strain K84. Field data from Spain confirm that pAgK84 can transfer to pathogenic recipients from strain K84 but not from strain K1026. The latter has been registered in Australia as a pesticide and is the first genetically engineered organism in the world to be released fro commercial use. It is recommended as a replacement for strain K84 to prevent a breakdown in the effectiveness of biological control of crown gall. Several reports indicate that both strains K84 and K1026 sometimes control crown gall pathogens that are resistant to agrocin 84. A possible reason for this is that both strains produce a second antibiotic called 434 which inhibits growth of nearly all isolates of A. rhizogenes, both pathogens and non-pathogens. Crown gall of grapevine is caused by another species, Agrobacterium vitis. It is resistant to agrocin 84 and cannot be controlled by strains K84 or K1026. It is different from other crown gall pathogens in several characteristics, including the fact that, although a rhizosphere coloniser, its also lives systemically in the vascular tissue of grapevine. Pathogen free propagating material can be obtained from tissue culture or, less surely, by heat therapy of dormant cuttings. A number of laboratories are searching for a biocontrol strain that will prevent, or at least delay, reinfection. A non-pathogenic A. vitis strain F/25 from South Africa looks very promising in this regard.

• Biomedical Science Letters
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• v.14 no.4
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• pp.269-274
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• 2008

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. It is associated with hospitals is now being isolated in the community. The aim of this study was to evaluate the antibacterial effect of photodynamic therapy using Photogem and 630 nm LED on MRSA and methicillin-sensitive Staphylococcus aureus (MSSA). The broth cultured MRSA and MSSA incubated with various concentrations of Photogem (500,50,5 and $0.5{\mu}g/mL$) for 4 h. Then 630 nm LED was given at $9\;J/cm^2$, $20{\mu}l$ of the exposed bacteria solution was inoculated onto agar plate. Plates were incubated for 24 hand colonies were counted. The PDT group was effective in killing MRSA and MSSA at the Photogem dose of $50{\mu}g/mL$. But MSSA is more sensitive than MRSA in photodynamic effect. Other groups (light only, sensitizer only, or no treatment) observed no bacterial cell killing. These results raise the possibility of using PDT with or without antimicrobial drugs to eradicate MRSA and MSSA. In order to confirm this result, we need to further study bacterial death mechanism and in vivo study.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.164-171
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• 2020

Transgenic Alstroemeria plants resistant to Alstroemeria mosaic virus (AlMV) were generated through RNA-mediated resistance. To this end, the friable embryogenic callus (FEC) of Alstroemeria was induced from the leaf axil tissue and transformed with a DNA fragment containing the coat protein gene and 3'-nontranslated region of AlMV through an improved particle bombardment system. The bar gene was used as a selection marker. More than 300 independent transgenic FEC lines were obtained. Among these, 155 lines resistant to phosphinothricin (PPT) were selected under low stringent conditions. After increasing the stringency of PPT selection, 44 transgenic lines remained, and 710 somatic embryos from these lines germinated and developed into shoots. These transgenic shoots were then transferred to the greenhouse and challenged with AlMV. In total, 25 of the 44 lines showed some degree of resistance. PCR analysis confirmed the presence of the viral sequence. Virus resistance was observed at various levels. Establishment of an efficient transformation system for Alstroemeria will allow inserting transgenes into this plant to confer resistance to viral and fungal pathogens. Accordingly, this is the first report on the production of a transgenic virus-resistant Alstroemeria and lays the foundation for alternative management of viral diseases in this plant.

• KSBB Journal
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• v.26 no.6
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• pp.543-551
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• 2011

Bacterial antibiotic resistance is a real and growing problem for both Gram positive and Gram negative bacterial pathogens in the hospital setting. Among Gram negative bacteria, the ubiquitous bacterium Pseudomonas aeruginosa is a particular concern in immunocompromised and burn patients. The present study evaluated antibacterial activity and efficacy of a Korean herbal medicine against eight multi-drug resistant clinical isolates of P. aeruginosa (0225, 0254, 0347, 0826, 1113, 1378, 1731, and 2492) isolated at Daegu Catholic University Hospital. Methanol extracts of Galla rhois (5 and 10 mg/mL) displayed inhibition diameters for isolate 2492 of 10 and 12 mm, respectively, in a conventional disc diffusion assay. In seven kinds of Korean herbal medicines, increased inhibitory power of Lonicera japonica, Gardenia jasminoides, Galla rhois, and Scultellaria baicalensis was evident with the fermentation of six kinds of lactic acid bacteria. Three lactic acid bacteria (Lactobacillus plantarum subsp. plantarum KCTC 3108, L. casei KCTC 3109, and L. fermentum KCTC 3112) were identified as excellent strains for the production of antibacterial materials. In the six Korean herbal medicine extracts, strong inhibitory activity of fermented Forsythia suspensa, Glycyrrhizae radix, Lycium chinense, Platycodon grum, and Schizandra chinensis with five kinds of lactic acid bacteria was evident for seven multi-drug resistant P. aeruginosa isolates.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.37-48
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• 2016

The transcriptional profiles of 'Tamnara' grapevine (Vitis labruscana L.) to Rhizobium vitis were determined using 12,000 gene oligonucleotide microarray chips constructed with 6,776 unigenes based on the EST sequencing. Among them, 95 clones were up-regulated more than three times and 90 were down-regulated more than 5-times in the R. vitis-inoculated grapevines relative to the control vines. Treatment of salicylic acid showed that 337 clones were upregulated and 52 clones were down regulated in grapevines. Microarray analysis, reverse transcription-polymer chain reaction, and slot blot hybridization analysis revealed that 5, 14, and 64 clones were up-regulated and 10, 12, and 61 clones were down-regulated in wounded, salicylic acid-treated, and R. vitis-inoculated 'Tamnara' grapevine leaves, respectively. The expression patterns of ${\beta}$-1,3-glucanase, proline-rich protein, and lipoxygenase genes of 'Tamnara' moderately resistant to R. vitis were similar to those of resistant 'Concord' and 'Delaware' grapevines. However, chalcone synthase genes in 'Tamnara' grapevines showed similar expression patterns to susceptible grapevines 'Neomuscat' and 'Rizamat'. Further expression studies with various clones for each gene should be conducted to elucidate their roles in resistant responses against pathogens or other stimuli in grapevines. These results could provide better resources for understanding the mechanism of defense responses against crown gall disease and clues for identifying new genes that may play a role in defense against R. vitis in grapevines.

• Biomedical Science Letters
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• v.18 no.1
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• pp.83-85
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• 2012

Vancomycin-resistant (VR)-E. faecium and VR-E. faecalis were isolated simultaneously from a rectal swab of a patient diagnosed with pneumonia in an intensive care unit (ICU). The patient was treated with various antibiotics including vancomycin. Only VR-E. faecium was continually isolated from the rectal swab at one and two weeks of the treatment. Identical vanA, IS1216V, and IS1542 genes were detected in both VR-E. faecium and VR-E. faecalis isolates which showed equal resistance against vancomycin and teicoplanin, but IS1251 was not detected. VR-E. faecium showed stronger multi-drug resistance than VE-E. faecalis. This result supports the reason why VR-E. faecium is one of the major pathogens in nosocomial infections.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.595-598
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• 2000

Aeromonas hydrophila is a pathogen to fish as well as human. It is a food-borne disease, and causes severe mortality in fish, and sometimes severe septicemia in human. In this study, a rapid detection method using latex agglutination has been developed for A. hydrophila. Polyclonal antibodies were raised against membrane and whole cells of three isolates from rainbow trout. Among these, latex particles coated with antibodies raised against whole cells of isolate No. 2 showed the best sensitivity. With latex particles coated with this antibody, we could detect $5{\times}10^4$ CFU of A. hydrophila in 5 min. The cross-reactivity with bacteria constituting the normal intestinal microflora and other pathogens for rainbow trout was insignificant. This latex agglutination assay method produced positive reaction with all clinical isolates of A. hydrophila which were identified by species-specific PCR for 16S rRNA in A. hydrophila.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.119-124
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• 2011

Currently, people are exposed to many harmful diseases. Therefore, there are many schemes, such as automation of productive facilities, development of information and communication technology, enhanced the quality of human life and wealth. However, these processes lead to weakened immune system. Thus, people are more vulnerable to infections from pathogens and environmental stress. Misuse and abuse of drugs resulted in the rapid emergence of multidrug-resistant microbes and tumors, therefore, to find new antibiotics are urgently needed. One of them is a peptide-antibiotic, that is not or less occurred a drug-resistance, comparing to conventional drugs. Peptides with various antibiotic activities have been identified from life organisms. The present review provides an overview of activities and application of peptide antibiotics.