• Mycobiology
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• 제30권2호
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• pp.88-92
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• 2002

Rehmannia glutinosa is a perennial medicinal plant belonging to the family Scrophulariaceae with more than 300 species known in the world, especially in temperate regions. Its roots have been used widely in Korea for medicinal purposes. However, it is commonly infected by various pathogens during storage, causing great damage to the roots, and impedes the intensive farming of the crop. Therefore, an attempt has been made to isolate and screen a resistance gene against the pathogen Fusarium oxysporum using differential display. We treated salicylic acid(SA), and isolated a resistance gene that responds to SA. As a result, we found that SA was involved in plant defense mechanism in pathogenicity tests with SA treated and non-treted plants, and we isolated a partial PR-la gene through differential display polymerase chain reaction(DD-PCR) method.

• 생명과학회지
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• 제23권5호
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• pp.703-709
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• 2013

본 연구에서는 ESBL을 생성하는 Escherichia coli의 Extended-spectrum ${\beta}$-lactamase (ESBL) 유전자와 퀴놀론 내성결정부위(qnr)의 유전자형과 항생제 내성 양상을 규명하고자 하였다. 임상검체에서 분리 된 E. coli 274개 균주를 대상으로 double-disk synergy test 검사를 실시하여 42개의 ESBL 생성 균주를 분리하였다. 검체별로는 소변에서 28균주가 분리되었으며, 객담에서 6균주, 농에서 3균주, 상처에서 2균주, 혈액에서 2균주 그리고 조직에서 1균주가 분리되었다. 이 균주들을 대상으로 ESBL 유전자와 퀴놀론 내성 유전자를 PCR을 이용하여 검색하였다. 35개의 균주가 1개 혹은 2개의 ESBL 유전자를 보유하고 있었다. ESBL 유전자의 분포는 CTX-M-1이 가장 많았으며, CTX-M-9과 TEM 유전자 순이었다. SHV, CTX-M-2와 CTX-M-8는 검출되지 않았다. qnr 유전자는 10개 균주에서 검출되었으며 유전형별로는 qnrB4, qnrB1, qnrS 1 순이었다. 2가지 이상의 ESBL 유전자를 동시에 보유한 균주와 ESBL과 qnr 유전자를 동시에 보유한 균주가 검출되었다. ESBL 유전자 보유균주는 cefotaxmie (80.0%), levofloxacin (82.9%)과 ampicillin (100%)에 고도내성을 보였다. qnr 유전자 보유 균주의 cefotaxmie, levofloxacin과 ampicillin에 대한 내성율은 각각 70%, 70%, 100%였다. ESBL 유전자들간의 그리고 qnr 유전자와의 동시 보유가 항생제 내성에 미치는 상승효과는 없었다. qnr 유전자 보유와 퀴놀론에 대한 내성 사이의 상관관계도 없었다.

• 한국자원식물학회지
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• 제29권6호
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• pp.658-669
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• 2016

Rice blast, caused by a fungus Magnaporthe oryzae, is one of the most devastating diseases of rice worldwide. Analyzing the valuable genetic resources is important in making progress towards blast resistance. Molecular screening of major rice blast resistance (R) genes was determined in 2,509 accessions of rice germplasm from different geographic regions of Asia and Europe using PCR based markers which showed linkage to twelve major blast R genes, Pik-p, Pi39, Pit, Pik-m, Pi-d(t)2, Pii, Pib, Pik, Pita, Pita/Pita-2, Pi5, and Piz-t. Out of 2,509 accessions, only two accessions had maximum nine blast resistance genes followed by eighteen accessions each with eight R genes. The polygenic combination of three genes was possessed by maximum number of accessions (824), while among others 48 accessions possessed seven genes, 119 accessions had six genes, 267 accessions had five genes, 487 accessions had four genes, 646 accessions had two genes, and 98 accessions had single R gene. The Pik-p gene appeared to be omnipresent and was detected in all germplasm. Furthermore, principal component analysis (PCA) indicated that Pita, Pita/Pita-2, Pi-d(t)2, Pib and Pit were the major genes responsible for resistance in the germplasm. The present investigation revealed that a set of 68 elite germplasm accessions would have a competitive edge over the current resistance donors being utilized in the breeding programs. Overall, these results might be useful to identify and incorporate the resistance genes from germplasm into elite cultivars through marker assisted selection in rice breeding.

• The Plant Pathology Journal
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• 제26권1호
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• pp.70-79
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• 2010

Rice blast is one of the serious devastating diseases. This study was carried out to determine the genetic diversities of blast resistance (R) genes form 86 accessions of aromatic rice with eight SNP markers, z4792, zt4792, z60510, zt6057, k6415, k6411, k39575 and t256, which showed the close-set linkage to 6 major genes, Piz, Piz-t, Pik, Pik-m, Pik-p, and Pit. Four accessions of indica type, Mayataung, Yekywin Yinkya Hmwe, Basmati9-93, and Basmati5854, showed the positive amplicons of six major genes. Among 86 accessions, 83 accessions were detected both or one of Piz and Piz-t genes. Seventy three accessions contained the Piz gene with z4792 marker. In addition, 30 and 71 accessions possessed Piz-t gene with zt4792 and zt6057 markers, respectively. Ten accessions showed the positive bands for the Piz-t gene with both zt4792 and zt6057 markers. Only one accession, Khau Nua Keo, was not amplified for both Piz and Piz-t gene. But japonica type, Gerdeh, possessed only Piz gene between Piz and Piz-t. Fifty two accessions showed the three of Pik multiple genes and Pit gene. Four accessions, Iari7447, Daebunhyangdo2, Shiyayuuine, and Basmati 6129 possessed a Pik-p gene. Especially, Pit gene on chromosome 1 was detected with t256 marker in all of 83 accessions, exception of A-2, one accession of japonica type.

• Pediatric Infection and Vaccine
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• 제3권2호
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• pp.133-138
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• 1996

Purpose : In the treatment of MRSA infection, rapid detection of MRSA is extremely important. The mecA gene codes the new drug resistant polypeptides called PBP2' which mediates the clinically relevant resistance to all beta-lactam antibiotics. The identical mecA gene has been found in coagulase-negative staphylococcus with the methicillin-resistant phenotype. On the other hand, the femA gene was absent from coagulase negative staphylococcus strains with the methicillin resistant phenotype. This study is aimed at early detection and definite diagnosis of MRSA. Methods : A total of 24 MRSA strains were studied. All strains were tested for antimicrobial susceptibility and purified DNA. We amplified both mecA and femA genes by PCR in 24 strains. Results : In MRSA all the 16 strains (100%) carried femA gene and 11 strains (68.7%) carried mecA gene. In contrast, in methicillin sensitive staphylococcus all the 8 strains (100%) carried femA and only 3 strains (37.5%) were detected mecA. Conclusions : As results, there are difference in the phenotype and genotype of methicillin resistance by PCR of mecA and femA. Such disparities between methicillin resistance and the presence of mecA gene suggest the presence of control gene of the mecA.

• 대한의생명과학회지
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• 제10권4호
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• pp.507-514
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• 2004

The Pseudomonas aeruginosa isolated from the clinical specimens has a mutation on the QRDR (quinolone resistance determining region). There were obvious mutations in both gyrA and parC gene which are major targets of quinolone. Simultaneous mutations were found two sites or more on these genes in all of ten strains. GyrB or parE gene had only silent mutation without converted amino acids. We confirmed that P. aeruginosa from clinical specimens exhibited decreased sensitivity to fluroquiolone due to changed Thr-83→lle and Asp-87→Asn types on gyrA and altered Ser-87→Leu type on parC. This is the first finding that a new Met-93→Thr type on parC as well as mutations on gyrB or parE genes differed from existing patterns. This study showed more mutations of gyrA rather than parC, suggesting that change of Type Ⅳ topoisomerase is more serious than that of type Ⅱ (DNA gyrase).

• Archives of Pharmacal Research
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• 제15권1호
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• pp.58-61
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• 1992

Bacillus anthracis 590 having an inducibla resistance determinant to MLS antibiotics was isolated from a soli sample in Korea. The resistance gene (ernJ) was cloned by Southern blotting of chromosomal DNA fragment digested by various restriction enzymes and coloy hybridization method and the cloned plasmid was named as pBA423. The size of inserted DNA fragment of pBS42 vector was about 2.9 kb and the DNA sequence of the subcloned fragment (Hinc II-Hinc II, 1.4kb) WAS determined. The DNA sequence of ernJ was composed of 357 bp for leader region and 861 bp for the structural gene. Because the leader sequence of ernJ was homologous to that of ermK, the expression of ernJ is also thought to be controlled by a transcriptionl attenuation mechanism.

• Journal of Microbiology
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• 제42권2호
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• pp.143-146
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• 2004

Vancomycin-resistant Enterococcus faecium (VREFM) is becoming a threatening pathogen. We identified a gene called DD1.5K by differential display-PCR, which was preferentially expressed in the bloodstream isolates of VREFM. Due to its amino acid similarity to transfer complex protein, trsE, and tissue-specific expression, this gene may be involved in virulence of VREFM.

• 한국육종학회지
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• 제41권2호
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• pp.73-83
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• 2009

To investigate genes related to vernalization and cold- resistance in barley (Hordeum vulgare L. cv. Nagaoka), differentially expressed genes were identified from cold-resistant barley leaves with suppression subtractive hybridization (SSH) and Northern blot analyses. The nucleotide and the deduced amino acid sequences of the putative gene products were compared. The bvrn-7 showed high homology(84%) with gene related to vernalization, and the bvrn-3, bvrn-12, bvrn-28, bvrn-29 and bvrn-36 related to cold-resistant genes had high identity of 88~98% with low temperature-induced genes. The results indicate that the 6 genes were closely related to vernalization and cold-resistance during low temperature treatment.

• 한국응용곤충학회지
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• 제41권2호
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• pp.113-121
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• 2002

벼멸구를 저항성 품종에서 도태시켰을 때 새로운 생태형으로 발전되는 속도와 벼멸구의 생태형과 벼의 품종저항성 간에 유전적으로 대응하고 있는지를 알아보고자, 감수성품종(동진벼)으로 사육하던 벼멸구를 Bph1 gene을 가진 저항성품종(청청벼)으로 각각 3세대 및 6세대 도태시킨 후, 같은 Bph1 gene을 가진 4개 품종(Mudgo, IR26, IR64, 청청벼)과, 다른 bph2 gene을 가진 2개 품종(밀양63호 및 가야벼)및 저항성이 없는 2개 품종(동진벼, TN-1)을 공시하여 각 계통의 벼멸구의 산란 및 섭식선호성, 수명, 발육기간, 사충율, 산란수 등을 조사하였다. 그 결과 감수성 벼멸구(생태형-1)를 저항성 Bph1 유전자를 갖인 청청벼에서 3세대(청청3세대계)및 6세대(청청6세대계)로 도태시켰을 때, 사육세대가 많아질수록 청청벼에서의 성충의 수명은 길어지고, 산란수는 많아지며, 또한 약충의 우화율이 높아지고, 약충기간이 짧아지는 등 빠르게 저항성을 극복하였다. 청청3세대계 및 6세대계 벼멸구는 청청벼와 같은 Bph1저항성 유전자를 가진 다른 품종들(Mudgo, IR26, IR64)에 대해서도 도태세대수가 많아지면서 선호성이 점점 높아지는 경향이었다. 성충의 수명과 산란수에 있어서도 청청3세대계, 청청6세대계 등으로 도태세대가 많아질수록 같은 저항성 Bph1유전자를 가진 Mudgo, IR26, IR64등에서 수명이 길어지고 산란수도 많아졌다. 벼멸구의 약충기간은 품종과 벼멸구 도태계통간에 큰 차이가 없었다. 그러나, 약충기간 중 사망률은 도태가 진행되면서 역시 Bph1저항성 gene의 4개 품종 모두에서 낮아졌고, 죽은 개체의 수명도 길어졌다. 밀양 63호(bph2 gene)와 가야벼(Bph1+bph2 gene) 등 2개 품종에서는 벼멸구의 3개 계통 모두 우화하지 못했다.