• 한국식물병리학회지
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• 제14권3호
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• pp.278-285
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• 1998

Effects of chitosan on growth of tomato plant, and suppression of Fusaruim wilt caused by Fusarium oxysporum f. sp. lycopersici and late blight casued by Phytophthora infestans, were examined. Both late blight and fusarium wilt were suppressed by spray and irrigation of chitosan, respectively. Inhibition of mycelial growth was not greatly affected by molecular size of chitosan but, concentration dependent effects was observed. Ninty percent of P. infestans and 80% of F. oxysporum f. sp. lycopersici of mycelial growth was inhibited by 1,000 ppm of chitosan (MW 30,000~50,000) when amended in plate media. Induction of defense-related gene expression in plant by chitosan treatments were observed when chitosan treated tobacco and tomato RNA samples were hybridized with several defense-related genes as probes. The results revealed that $\beta$-1,3-glucanase and chitinase genes were strongly induced, while pathogenesis-related protein-1, 3-hydroxy-3-methylglutaryl coenzyme A reductase, anionic peroxidase, phenylalanine ammonia lyase genes were weakly induced by chitosan treatment. These results suggest that chitosan have dual effects on these host-pathogen interactions. Possible roles of chitosan in suppression of tomato diseases by inhibition of mycelial growth and activation of plant defense responses are discussed.

• 대한수의학회지
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• 제34권4호
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• pp.759-768
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• 1994

E coli strains isolated from pigs were investigated with respect to antimicrobial resistances and prevalence of R-plasmids. Also determined were properties of R-plasmids by plasmid conjugation, curing and southern hybridization using gene probes. All of 400 E coli strains were resistant to CL and SU, and 0.3% to 96.8% of the strains were resistant to most antimicrobials such as TC, PG, AM, SM, CP, GM, EM, NM, etc, while all strains were sensitive to AK. All strains were also multiply resistant to three to twelve antimicrobials. The resistances to PG, SM, TC, AM, CP, SU and ST were transferable and supposed to be mediated by R-plasmids which were opportunistic for transposition into chromosome. Plasmids bigger in size than chromosomal DNA were considered as R-plasmids and most plasmids in small size (<4Kb) proved as cryptic plasmids or nonconjugative R-plasmids. In a strain(No 99), AM resistant property was determined from both chromosomal DNA and R-plasmid DNA which is bigger in size than chromosome.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.152-157
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• 2003

Diesel-contaminated soils were ozonated for different times (0 - 900 min) and incubated for 9 wk to monitor petroleum hydrocarbons (PH)-degradative potential of indigenous microorganisms in the soils. Increased ozonation time decreased not only concentration of PH but also number of microorganisms in the soils. Microorganisms in the ozonated soils increased during 9-wk incubation as monitored by culture- and nonculture-based methods. Higher (1-2 orders of magnitude) cell number was observed by quantitative analysis of soil DNA using probes detecting genes encoding 165 rRNA(rrn), naphthalene dioxygenase (nahA), toluene dioxygenase (todC), and alkane hydroxylase (alkB) than microbial abundance estimated by culture-based methods. Such PH-degraders were relatively a few or under detection limit in 900-min ozonated soil. Further PH-removal observed during the incubation period supported the presence of PH-degraders in ozonated soils. Highest reduction (25.4%) of total PH (TPH) was observed in 180-min ozonated soil white negligible reduction was shown in 900-min ozonated soil during the period, resulting in lowest TPH-concentration in 180-min ozonated soil among the ozonated soils. Microbial community composition in 9-wk incubated soils revealed slight difference between 900-min ozonated and unozonated soils as analyzed by whole cell hybridization using group-specific rRNA-targeted oligonucleotides. Results of this study suggest that appropriate ozonation and subsequent biodegradation by indigenous microorganisms may be a cost-effective and successful remediation strategy for PH-contaminated soils.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.197-201
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• 2004

A 2-D gel protein analysis of Lactobacillus reuteri ATCC 55739 produced spots corresponding to subunits of the pyruvate dehydrogenase complex, as identified by N-terminal protein sequencing. Oligonucleotide probes specific for the subunits of the pyruvate dehydrogenase complex were synthesized ,md used to screen a L. reuteri genomic library to clone the structural genes. Two positive clones were isolated and identified as having the same 2.2 kb insert. A pdhB encoding the $\beta$-subunit of El subunit (pyruvate dehydrogenase component) of the pyruvate dehydrogenase complex was located in the middle of the insert. Furthermore, a 5' truncated pdhA encoding the $\alpha$-subunit of the E1 subunit and a 3' truncated pdhC encoding the E2 subunit (dihydrolipoamide acetyltransferase) were also located upstream and downstream of the pdhB, respectively.

• Journal of Photoscience
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• 제5권3호
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• pp.131-135
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• 1998

Using differential display reverse transcription technique, the present study attempted to isolate and characterize genes specifically expressed in cotyledons of Pharbitis nil Choisy cv. Violet during floral induction. A total of 107 bands specific to the inductive condition were initially obtained with 80 primer sets of 20 different arbitrary primers combined with 4 kinds of T12MN. In northern blot analysis with reamplified cDNAs as probes, three cDNAs were detected to be expressed specificcally in the induced cotyledon tissues, and designated PnFL-1, PnFL-2 and PnFL-3 , the size of which were 228 bp, 317 bp and 272 bp, respectively. A search for sequences similar to the decuced amino acid sequences was conducted using GenBank and EMBL database ; seequence encoded by PnFL-1 had 29% identity with the clone of Arabidopsis thaliana similiar to reverse trascriptase (Genbank Acc. N0.3047086), PnFL-2 shared 50% identity with hydroxiyproline-rich glycoprotein of Glycine max(GenBank Acc. No.347455), and PnFL-3 had 46% identity with TAMU 4. Thaliana genomic clone T23E16 (GenBank Acc. No.B67574). None of them was known gene in the plant system up to date, implying that the fragments may comprise parts of genes which are associated with the floral induction in Pharbitis nil.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권6호
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• pp.265-270
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• 2002

The determination of DNA hybridization reaction can apply the molecular biology research, clinic diagnostics, bioengineering, environment monitoring, food science and application area. So, the improvement of DNA hybridization detection method is very important for the determination of this hybridization reaction. Several molecular biological techniques require accurate predictions of matched versus mismatched hybridization thermodynamics, such as PCR, sequencing by hybridization, gene diagnostics and antisense oligonucleotide probes. In addition, recent developments of oligonucleotide chip arrays as means for biochemical assays and DNA sequencing requires accurate knowledge of hybridization thermodynamics and population ratios at matched and mismatched target sites. In this study, we report the characteristics of the probe and matched, mismatched target oligonucleotide hybridization reaction using thermodynamic method. Thermodynamic of 5 oligonucleotides with central and terminal mismatch sequences were obtained by measured UV-absorbance as a function of temperature. The data show that the nearest-neighbor base-pair model is adequate for predicting thermodynamics of oligonucleotides with average deviations for $\Delta$H$^{0}$ , $\Delta$S$^{0}$ , $\Delta$G$_{37}$ $^{0}$ and T$_{m}$, respectively.>$^{0}$ and T$_{m}$, respectively.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.1-8
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• 2013

Taenia solium, T. saginata, and T. asiatica are taeniid tapeworms that cause taeniasis in humans and cysticercosis in intermediate host animals. Taeniases remain an important public health concerns in the world. Molecular diagnostic methods using PCR assays have been developed for rapid and accurate detection of human infecting taeniid tapeworms, including the use of sequence-specific DNA probes, PCR-RFLP, and multiplex PCR. More recently, DNA diagnosis using PCR based on histopathological specimens such as 10% formalin-fixed paraffin-embedded and stained sections mounted on slides has been applied to cestode infections. The mitochondrial gene sequence is believed to be a very useful molecular marker for not only studying evolutionary relationships among distantly related taxa, but also for investigating the phylo-biogeography of closely related species. The complete sequence of the human Taenia tapeworms mitochondrial genomes were determined, and its organization and structure were compared to other human-tropic Taenia tapeworms for which complete mitochondrial sequence data were available. The multiplex PCR assay with the Ta4978F, Ts5058F, Tso7421F, and Rev7915 primers will be useful for differential diagnosis, molecular characterization, and epidemiological surveys of human Taenia tapeworms.

• The Plant Pathology Journal
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• 제39권6호
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• pp.614-624
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• 2023

Botrytis cinerea is a major fungal plant pathogen that causes gray mold disease in strawberries, leading to a decrease in strawberry yield. While benzimidazole is widely used as a fungicide for controlling this disease, the increasing prevalence of resistant populations to this fungicide undermines its effectiveness. To investigate benzimidazole resistant B. cinerea in South Korea, 78 strains were isolated from strawberries grown in 78 different farms in 2022, and their EC₅₀ values for benzimidazole were examined. As a result, 64 strains exhibited resistance to benzimidazole, and experimental tests using detached strawberry leaves and the plants in a greenhouse confirmed the reduced efficacy of benzimidazole to control these strains. The benzimidazole resistant strains identified in this study possessed two types of mutations, E198A or E198V, in the TUB2 gene. To detect these mutations, TaqMan probes were designed, enabling rapid identification of benzimidazole resistant B. cinerea in strawberry and tomato farms. This study utilizes TaqMan real-time polymerase chain reaction analysis to swiftly identify benzimidazole resistant B. cinerea, thereby offering the possibility of effective disease management by identifying optimum locations and time of application.

• 한국동물학회지
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• 제27권2호
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• pp.103-116
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• 1984

유전자 구조 및 유전정보 흐름의 차이로 인하여 고등생물의 유전자를 미생물에 직접 cloning하면 원하는 유전자 산물을 얻지 못하는 경우가 많다. 이것을 극복하기 위해서는 화학적인 방법으로 유전자를 합성하든지, 또는 역제효소를 사용하여 고등생물의 mRNA로부터 유전자를 합성하여 cloning하는 방법을 사용한다. 본 연구에서는 oligo(dT)-cellulose column 방법으로 순수분리한 plasmid pBR322의 Pst I site에 cloning하였다. 우선 AMV reverse transcriptase로 primary cDNA를 합성하고, 알칼리를 처리하여 주형 RNA를 제거했다. 이번에는 이 primary cDNA를 주형으로 Klenow enzyme과 reverse transcriptase를 차례로 처리하여 double stranded DNA를 합성하고, 이 때 5' end 근처에 형성되는 hairpin loop을 Sl nuclease로 제거했다. Terminal deoxynucleotidyl transferase를 사용하여, 합성된 dsDNA에는 poly(dC) track을, Pst I endonuclease를 처리한 plasmid DNA에서는 poly(dG) track을 각각 붙인다음 이들을 서로 annealing시키고 E. coli에 transformation시켜서 크기가 큰 plasmid를 갖는 clone을 cracking 방법으로 일처 선별하였다. 이렇게 선별된 clone을 in 냐셔 hybridization 방법으로 조사하여 globin DNA가 들어간 colony를 이차 선별하고 여러 restriction enzyme으로 잘라보아 globin DNA가 cloning된 것을 확인하였다. 토끼 hemoglobin으로 immunize한 rat (Wistar)에서 뽑은 제일차 혈청과 염소에서 뽑은 제이차 혈청의 antibody를 사용한 radioimmunoassay방법으로, cloning된 globin gene이 대장균내에서 발현되는 지의 여부를 살펴 보았는데, 박테리아의 $\\beta$-lactamase와 토끼의 globin이 결합된 chimeric protein이 대장균 내에서 다량 합성되며, 이 단백질은 토끼 hemoglobin의 antigenic determinant를 가지고 있음을 알 수 있었다.

• Parasites, Hosts and Diseases
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• 제56권5호
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• pp.419-427
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• 2018

This study aimed to develop a new multiplex real-time PCR detection method for 3 species of waterborne protozoan parasites (Cryptosporidium parvum, Giardia lamblia, and Cyclospora cayetanensis) identified as major causes of traveler's diarrhea. Three target genes were specifically and simultaneously detected by the TaqMan probe method for multiple parasitic infection cases, including Cryptosporidium oocyst wall protein for C. parvum, glutamate dehydrogenase for G. lamblia, and internal transcribed spacer 1 for C. cayetanensis. Gene product 21 for bacteriophage T4 was used as an internal control DNA target for monitoring human stool DNA amplification. TaqMan probes were prepared using 4 fluorescent dyes, $FAM^{TM}$, $HEX^{TM}$, $Cy5^{TM}$, and CAL Fluor $Red^{(R)}$ 610 on C. parvum, G. lamblia, C. cayetanensis, and bacteriophage T4, respectively. We developed a novel primer-probe set for each parasite, a primer-probe cocktail (a mixture of primers and probes for the parasites and the internal control) for multiplex real-time PCR analysis, and a protocol for this detection method. Multiplex real-time PCR with the primer-probe cocktail successfully and specifically detected the target genes of C. parvum, G. lamblia, and C. cayetanensis in the mixed spiked human stool sample. The limit of detection for our assay was $2{\times}10$ copies for C. parvum and for C. cayetanensis, while it was $2{\times}10^3$ copies for G. lamblia. We propose that the multiplex real-time PCR detection method developed here is a useful method for simultaneously diagnosing the most common causative protozoa in traveler's diarrhea.