• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.64.2-64
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• 2003

Twenty-seven monogenic rice lines harboring major resistant gene for blast were screened to analyze their resistance spectrum to Korean blast fungus population using 190 isolates collected from 1985 to 2002. Especially, the monogenic line containing Pi-9 gene was screened using 320 isolates. Based on the monogenic lines-blast isolate interactions, the 27 rice lines were classified into 9 groups. The chinese rice cultivar LTH showed susceptible to all the tested isolates. Those lines IRBLz-Fu, ERBL5-M and IRBL9-W harboring Pi-z, Pi-5, and Pi-9, respectively showed broader spectrum of resistance than those rice lines having Pi-19, Pi-7 etc. Interestingly, the Pi-9 gene(IRBL9-W) showed resistance to most isolates collected before 2000, but it showed susceptible reactions to 5％ and 20％ of blast fungus population in 2001 and 2002, respectively. Population of virulent isolates to Pi-ta, Pi-b, and Pi-7 also were increased in 2002 compared to those before 2000.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.177-180
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• 2008

Worldwide, cyst nematode(Heterodera glycines Ichinohe) is the most destructive pathogen of cultivated soybean. In the USA, current annual yield losses are estimated to be nearly a billion dollars. Crop losses are primarily reduced by the use of resistant cultivars. Nematode populations are variable and have adapted to reproduce on resistant cultivars over time because resistance primarily traces to two soybean accessions. It is important to use diverse resistance sources to develop new nematode resistant cultivars. Soybean PI 494182 is a recent introduction from Japan and found to be resistant to multiple nematode populations. It is yellow seeded and maturity group 0. We have determined inheritance of resistance in PI 494182 using $F_{2:3}$ families derived from cross PI 494182 X cv. Skylla. Skylla is a susceptible parent. Three nematode populations, races 1, 3, and 5, corresponding to HG types 2.5.7, 0, and 2.5.7 were used to bioassay 162 $F_{2:3}$ families in greenhouse experiments. Based on Chi-square tests, a two-gene model is proposed for resistance to race 1 and a three-gene model is proposed for conditioning resistance to both races 3 and 5. Correlation coefficient analysis indicated that some genes conditioning resistance to races 1, 3, and 5 are shared or closely linked with each other. These results will be useful to soybean breeders for developing soybean cultivars for broad resistance to nematodes.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.154-158
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• 2010

Early nematode development and subcellular responses in resistant soybean lines PI 88788 and PI 437654 infected with races 3 (R3) and 14 (R14) of soybean cyst nematode (SCN), Heterodera glycines Ichinohe, were compared. SCN R14 nematodes penetrated and developed significantly more than R3 at 5-6 days after inoculation. Both races also penetrated and developed more in PI 88788 than in PI 437654. Syncytia, characterized by cell wall dissolution and cellular hypertrophy, were developed more in PI 88788 than in PI 437654 and more by R14 than R3, for which less necrotic responses occurred in the former than the latter. This suggests that the latter two may be more resistant and less virulent than the former two, respectively. A common structural feature found in each of PI 437654 and PI 88788 in relation to SCN-resistance was the formation of prominent cell wall appositions and nuclear degeneration prior to cytoplasmic degradation in syncytial cells, respectively. Necrosis and cell wall apposition are types of hypersensitive responses occurring at early stages of the nematode infection so that these structural modifications indicate the inhibition of initial syncytial development related to the early nematode development. As soybean cultivars and lines with identical or similar genotypes have the same types of structural features related to SCN-resistance, the structural modifications induced by SCN infection may result from the expression of inheritable resistance genes, of which the information can be used for breeding soybean cultivars and lines specifically resistant to SCN races.

• Journal of Life Science
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• v.9 no.1
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• pp.40-44
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• 1999

Glutathione S-transferase (GST) is a multifunctional protein that catalyzes the catalyzes the conjugation of glutathione with electrophilic compounds. It exists in a variety of isoenzy-matic froms with a wide range of substrate specificity and plays a pivotal role in detoxification of various drugs. In order to elucidate the GST-${\pi}$'s involvement of multidrug resistance (MDR) in drug-resistant tumor cell lines, we determined GST-${\pi}$ content by "1 step sandwich method". Consequently, adriamycin resistant cells of MCF-7 (MCF-7/ADM) have 7-fold increase of GST-${\pi}$ content than that of MCF-7 cells, while its {TEX}$IC_{50}${/TEX} was 116-fold greater than parent cell line. By northrn blotting, we compared whether MCF-7/ADM cells express GST-${\pi}$ mRNA. The GST-${\pi}$ mRNA expression in these cells was not inducible, but constitutive when treated for 24 h with a concentration of 0, 20, 200, and 2000 nM of adriamycin, respectively. Taken together, these results suggest that GST-${\pi}$ may not be directly associated with multidrug resistance in these human cancer cell lines.ell lines.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.13-16
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• 2008

Pepper fruit anthracnose caused by Colletotrichum species is an economically important disease that causes serious yield loss and quality deterioration in many Asian countries including South Korea and Taiwan. Recently, Capsicum baccatum PI594137 was found to exhibit broad-spectrum resistance to Colletotrichum acutatum. The inheritance of anthracnose resistance to C. acutatum was analyzed in an intraspecific population derived from a cross between C. baccatum Golden-aji and PI594137. Detached mature green fruits were inoculated using the microinjection method. The disease response was evaluated as the disease incidence and the overall lesion diameter at 7 days after inoculation(DAI). The segregation ratios of resistance and susceptibility to C. acutatum in the $F_2$ and $BC_s$ populations significantly fit a 3:1 Mendelian model. This result indicates that the resistance of PI594137 to C. acutatum is controlled by a single dominant gene.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5619-5625
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• 2012

Gastric carcinoma is a leading cause of cancer death in the world and multi-drug resistance (MDR) is an essential aspect of gastric carcinoma chemotherapy failure. Recent studies have shown that integrin-linked kinase (ILK) is involved in metastasis of human tumors, expression silencing of ILK inhibiting the metastasis of several types of cultured human cancer cells. However, the role and potential mechanism of ILK to reverse the multi-drug resistance in human gastric carcinoma is not fully clear. In this report, we focused on roles of expression silencing of ILK in multi-drug resistance reversal of human gastric carcinoma SGC7901/DDP cells, including increased drug sensitivity to cisplatin, cell apoptosis rates, and intracellular accumulation of Rhodamine-123, and decreased mRNA and protein expression of multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), glutathione S-transferase -${\pi}$ (GST-${\pi}$) and RhoE, and transcriptional activation of AP-1 and NF-${\kappa}B$ in ILK silenced SGC7901/DDP cells. We also found that there was a decreased level of p-Akt and p-ERK. The results indicated that ILK might be used as a potential therapeutic strategy to combat multi-drug resistance through blocking PI3K-Akt and MAPK-ERK pathways in human gastric carcinoma.

• Korean Journal of Plant Resources
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• v.29 no.6
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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.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.437-444
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• 1996

경북지역 재래종에 더뎅이병 저항성을 도입하기 위하여 작성한 칼미초$\times$PI271322, 수비초$\times$PI271322 조합의 BC\ulcornerF\ulcorner와 BC\ulcornerF\ulcorner세대로부터 BC\ulcornerF\ulcorner와 BC\ulcornerF\ulcorner세대까지 선발과 자식을 실시하였다. 이 결과 각 재래종의 원예적 특성에 PI271322에 들어있는 과민반응형 저항성 유전자 Bs\ulcorner와 비과민형의 일반저항성을 함께 가지는 계통이 육성되었다.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.73-77
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• 1994

Experiments were conducted to determine the method of nioculation and inoculum level, and the optimum age of pepper seedlings for evaluation of resistance to bacterial wilt in pepper. Injection of bacterial suspension(107~108 cells/ml) to the leaf axil of the 3rd or 4th leaf of pepper, and drenching the soil planted with pepper seedling after wounding roots with scalpel, resulted in good varietal difference in resistance to bacterial wilt. PI377688, PI358812 and PI369994 of 298 open-pollinated lines and 10 hybrids tested for resistance to bacterial wilt were highly resistant and such local cultivars as Masan, Anjinbaengi, Kimyongcho and Punggakcho moderately resistant.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.23-28
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• 1994

A leading sweet pepper cultivar, Keystone Resistant Giant #3, was crossed with a line with resistance to Xanthomonas campestris pv. vesicatoria, PI271322, for incorporation of the resistance and to study the inheritance of resistance to the disease. Seedlings of parents, $F_1$, $F_2$ and backcross populations of a cross between Keystone Resistant Giant #3 and PI271322 were inoculated with race 1 and race 3 of Xanthamonas campestris pv. vesicatoria by infiltrating bacterial suspension into abaxial side of leaves. PI271322 was carrying a gene ($Bs_3$) for hypersensitive resistance to race 1 of X. c. pv. vesicatoria and also a component of non-hypersensitive resistance to race 3 inheriting in a quantitative mode. Correlation coefficient between disease indices to race 1 and race 3 of non-hypersensitive plants in $F_2$ population was highly significant, thus indicating that a component of non-hypersensitive general resistance in PI271322 acted consistently to both races. Individual plants with resistance to both race 1 and race 3 of X. c. pv. vesicatoria were selected and a breeding program for incorporation of the resistance is continued.