• Research in Plant Disease
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• v.22 no.4
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• pp.297-302
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• 2016

Tomato yellow leaf curl virus (TYLCV) is a viral disease causing severe economic losses on tomato. Practical prevention of the TYLCV disease is to control tabacco whitefly (Bemisia tabaci) or to cultivate TYLCV-resistant tomato cultivars, because no agrochemical products are available to control TYLCV. In this study, TYLCV resistance of the commercial tomato cultivars were evaluated using the DNA markers tightly linked to TYLCV resistance genes Ty-1 and Ty-3 and infection with the TYLCV clones mediated by Agrobacterium. In marker genotyping, resistance alleles were detected from 4 oval type tomato cultivars (Titichal, TY tinny, TY saengsaeng II, TY sense Q). Four cheery type cultiavrs (TY endorphin, TY smartsama, Tiara TY, Olleh TY) and 6 round type cultivars (TY kingdom, TY ace, TY homerun, TY altorang, Dotaerang TY winner, Styx TY). The seedling bioassay indicated that tomato cultivars of the oval type and cherry type showed consistancy in marker genotype and phenotype while slight disease symptom was observed from some round type cultivras (TY ace, TY homerun, Styx TY) with resistance marker genotype. For fruit yields, TY tinny was greater than its control cultivar Titichal in oval types, TY smartsama was greater than its control Smile in cherry type, and TY ace and TY kingdom were greater than their control Dabok. These cutliavrs can be a good choice for high-yielding TYLCV-resistant tomato cultivars.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.133-133
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• 2017

Lodging is one of the important constraints in rice production. The lodging destroys the canopy structure, and sharply reduces the capacity of photosynthetic rate and dry matter production. In cereal crops, stem lodging can be classified into two types: stem breaking type and stem bending type. To improve stem lodging resistance, it is important to reveal strong culm traits of superior lodging resistant varieties. There are large varietal differences in parameters associated with the bending moment at breaking (M) and flexural rigidity (FR). The indica variety Takanari possesses large M due to its large section modulus (SM) despite of its small bending stress (BS), while Takanari also has large FR due to its large secondary moment of inertia (SMI) and Young's modulus (YM). To identify quantitative trait loci (QTLs) and the corresponding genes associated with the parameters for M ($=SM{\times}BS$) and FR ($=SM{\times}YM$) should enable to develop lodging resistant varieties, efficiently. In order to identify QTLs for cell wall materials such as cellulose, hemicellulose and lignin associated with BS and YM, a set of Chromosome Segment of Substitution Lines (CSSLs) consisted of 37 lines with chromosome segments of Koshihikari in the genetic background of Takanari were used. Takanari had large M and small BS as compared with Koshihikari. The QTLs for BS were estimated on chromosomes 3, 5, 6, 8, 9, 10, 11 and 12. Koshihikari alleles increased BS in these QTLs. Takanari had a large FR due to its large SMI and YM as compared with Koshihikari. The YM was increased by substitution of the Koshihikari chromosomal segments on chromosomes 2, 10 and 11. Other QTLs estimated on chromosomes 7 and 12 that Koshihikari alleles contributed to the decrease of YM. For lignin, only one major QTL for lignin density was detected on chromosome 11. Hollocellulose densities were increased by the substitution of Koshihikari segments on chromosomes 5 and 11. On the other hand, these were decreased on chromosomes 1 and 3 by substitution of Koshihikari segments. QTLs for cellulose density were estimated on chromosomes 1, 3 and 5 by substitution of Koshihikari segments. For hemicellulose, QTL on chromosome 3 showed that hemicellulose density decreased by the substitution of Koshihikari segment. However, hemicellulose densities on chromosomes 5, 8 and 11 showed the opposite effects. The QTLs for hemicellulose, cellulose, and hollocelulose densities identified on chromosome 5 overlapped with that for bending stress, indicating the positive effect of Koshihikari segment on increasing bending stress. These results suggest that some QTLs for the densities of cell wall materials contribute to increasing bending stress and Young's modulus, and could be utilized to improve the lodging resistance for both types of breaking and bending in rice varieties.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.127-133
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• 2014

Four transgenic rice lines harboring insect-resistant gene cry3A showed ideal field performances characterized by high considerable resistance to rice water weevil (Lissorhoptrus oryzophilus Kuschel). In this study, we estimated the insertion number of foreign genes, and analyzed the flanking sequences of T-DNAs in rice genome. As a result, T-DNA of BT12R1 line was inserted in exon region of rice chromosome 10. Two copies of T-DNAs were inserted in line BT12R2. BT12R3 line was analyzed at only left border flanking sequence. BT12R4 line was confirmed one copy of foreign gene insertion at the position 24,516,607 ~ 24,516,636 of rice chromosome 5, accompanied by a deletion of 30 bp known genomic sequences. This intergenic position was confirmed none of expressed gene and any deletion/addition of T-DNA sequence. In conclusion, these molecular data of rice water weevil resistant Bt rice would be used to conduct the biosafety and environment risk assessment for GM crop commercialization.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3309-3315
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• 2016

Helicobacter pylori as the second most common cause of gastric cancer in the world infects approximately half of the developed countries population and 80% of the population living in developing countries. Integrons as genetic reservoirs play major roles in dissemination of antimicrobial resistance genes. To the best of our knowledge, this is the first study to report carriage of class 1 and 2 integrons and associated gene cassettes in H. pylori isolates from Iran. This cross-sectional study was conducted in Tehran among 110 patients with H. pylori infection. Antimicrobial susceptibility testing (AST) for H. pylori strains were assessed by the micro broth dilution method. Class 1 and 2 integrons were detected using PCR. In order to determine gene cassettes, amplified fragments were subjected to DNA sequencing of both amplicon strands. The prevalence of resistance to clarithromycin, metronidazole, clarithromycin, tetracycline, amoxicillin, rifampin, and levofloxacin were 68.2% (n=75), 25.5% (n=28), 24.5% (n=27), 19.1% (n=21), 18.2% (n=20) and 16.4% (n=18), respectively. Frequency of multidrug resistance among H. pylori isolates was 12.7%. Class 2 integron was detected in 50 (45.5%) and class 1 integron in 10 (9.1%) H. pylori isolates. The most predominant gene cassette arrays in class 2 integron-bearing H. pylori were included sat-era-aadA1, dfrA1-sat2-aadA1, blaoxa2 and, aadB whereas common gene cassette arrays in class 1 integron were aadB-aadA1-cmlA6, aacA4, blaoxa2, and catB3. The high frequency of class 2 integron and multidrug resistance in the present study should be considered as a warning for clinicians that continuous surveillance is necessary to prevent the further spread of resistant isolates.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.281-287
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• 1999

Codonopsis lanceolata ("Deoduck" in Korea) is a perennial herb, and belongs to family, Campanulaceae. Its taproot is used a good source of a wild vegetable as well as an herbaceous medicine. In this study, to develop a bialaphos-resistant transgenic Codonopsis, seed germination mechanism and somatic embryogenesis of the plant were investigated, and Agrobacterium-mediated transformation with bar gene encoding phosphinothricin acetyltransferase (PAT) was performed. Attempt were made to regenerate plant from cells via somatic embryogenesis. When the cotyledons, nodes and leaf disks were cultured on MS medium containing 2,4-D and zeatin, embryogenic calli were induced. Upon transferring the somatic embryos to N6 solid medium without plant growth regulators, they developed into plantlets under continuous illumination. All plants were dead on MS basal medium containing 10 mg/L phosphinothricin (PPT) and Basta, respectively. The explants did not produce calli in the medium containing 200 mg/L kanamycin. The explants were cocultured with Agrobacterium tumefaciens for 2 days, and transformants were selected in MS basal medium containing 1.0 mg/L 2,4-D, 100 mg/L kanamycin and 500 mg/L carbenicillin. After the selection, embryogenic calli were induced and then somatic embryos were produced by subsequent subculturing. The somatic embryos were germiated on N6 basal medium containing 200 mg/L kanamycin and 500 mg/L carbenicillin. PCR analysis showed that nptII and bar genes were introduced in the Deoduck transformants. After the confirmation of bar gene expression in RNA and protein level, the transgenic Deoduck will be used to study the genetics of filial generation with the herbicide control gene, bar.gene, bar.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.163-169
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• 1999

This study was conducted to produce herbicide resistant plants by transferring phosphinothricin acetyltransferase (PAT) gene into Populus alba $\times$ Populus glandulosa No .3 using Agrobacterium tumefaciens MP 90/PAT. Leaf segments from in vitro grown shoots of hybrid poplar No. 3 were soaked in a AB medium containing Agrobacterium tumefaciens MP 90/PAT for 10 min and cocultivated for 2 days on MS medium containing 1.0 mg/L 2,4-D and 0.2mg/L kinetin (CIM). Putative transformed calli could be selected after cocultivation of leaf segments on CIM supplemented with 50mg/L kanamycin and 500mg/L cefotaxime for 3 weeks. The selected calli were cultured on CIM supplemented with 50 mg/L kanamycin and 500 mg/L cefotaxime for 5~8 weeks before transfer to WPM containing 1.0mg/L zeatin, 0.1mg/L BAP, 50 mg/L kanamycin and 500mg/L cefotaxime for shoot regeneration. Shoots were regenerated from the callus after 4 week cultivation, and the regenerants were grown on the same medium for 7~l0 weeks. The plants rooted on 1/2 WPM containing 0.2 mg/L IBA and 50 mg/L kanamycin. To confirm the gene insertion into plants, GUS activity was detected by histochemical assay in the transformed plants. Finally, the presence of both NPT II and PAT genes from the transgenic plants were confirmed by PCR amplification with the gene specific primers and subsequent PCR-Southern blot with DIG-labeled PAT gene probe. After acclimatization in pots for 4 weeks, the plants were sprayed by 3 mL/L of Basta to test resistance to the herbicide. The transgenic plants remained green, whereas all the control plants died after one week.

• Korean Journal of Veterinary Service
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• v.34 no.1
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• pp.45-54
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• 2011

This study was conducted to investigate the distribution of Salmonella spp. from pigs and cattle in slaughterhouse, the antimicrobial resistance pattern and the prevalence of resistance genes of isolates. A total of 640 fecal samples from pigs and cattle in slaughterhouse were collected for isolation of Salmonella spp.. Isolation rate was revealed as 15% in pigs and 1.6% in cattle. As result of serotyping, group B (56.6%) were identified as most common in pigs and cattle isolates, in order of group C (24.5%) and group E (15.1%). S. Typhimurium (50.9%) was most common serotype. The major serotypes were in order of S. Rissen and S. London (11.3%) and S. Riggil (7.6%). In antimicrobial test, all isolates were demonstrates susceptibility to nitrofurantoin. But isolates were revealed resistance other antibiotics in order of tetracycline (64.6%), streptomycin (68.3%), ampicillin and amoxicillin (56.3%) and spectinomycin (47.9%). With polymerase chain reaction, antimicrobial resistance gene strA (75.0%) and aadA1 (3.1%) were detected in streptomycin resistance isolates and tetA (94.3%) and tetB (11.3%) gene were detected in tetracycline resistant isolates, but tetG was not detected. Class 1 integron gene was detected in all Salmonella isolates.

• Korean Journal of Medicinal Crop Science
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• v.11 no.2
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• pp.161-166
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• 2003

Korean ginseng(Panax gmseng C.A. Meyer) is very difficult to obtain stable production of qualified ginseng roots because of variable stresses in soil environments. In environment stresses, soil condition is the most important factor, among which nutrients, especially inorganic materials such as N, P, K, Ca, Mg, Fe, etc., influence greatly on the ginseng growth. However, present ginseng field soils in Korea contain so much amount of such inorganic materials that a variety of remarkable disorders were noted in many ginseng plantations, resulting in decrease of qualitative ginseng production. Therefore, it is required to search for genetic resources and genes tolerant to salt stress for the development of ginseng cultivars. Selection of stress-tolerant ginseng lines in fields is very difficult because it is almost impossible to control properly the environmental conditions of soil. On the contrary, it can be studied with ease to search for stress-tolerant ginseng lines through in vitro culture because of easy manipulation of stress conditions. Murashige & Skoog(MS) media with 2.5 folds of $KNO_3,\;NH_4NO_3,\;MgSO_4\;7H_2O,\;KH_2PO_4,\;and\;CaCl_2\;2H_2O$ was established for the selection of ginseng lines tolerant to salt stress under the embryo culture.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.156-161
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• 2002

Two different cDNA clones for superoxide dismutase (SOD) were isolated from an weedy rice variety (Oryza sativa, cv. Bhutan14Ad) and were introduced into a cultivated rice variety (Oryza sativa, cv. Nakdong) in order to develop the environmental stress-resistant rice plants. Sequence analysis of the cloned cDNAS indicated that the deduced amino acid sequence of SOD-A is 88.4% identical to that of SOD-B. Furthermore, the nucleotide sequence of SOD-A is 99.3% identical to that of a Cu/Zn SOD gene of Oryza sativa (GenBank accession No. L36320). The nueleotide sequence of SOD-B was identical to that of the previously published SOD gene (Accession No. D01000). A cultivated rice variety, Nakdong-byeo, was transformed with chimeric SOD genes containing a actin promoter of rice and pin2 terminator using a particle bombardment technique. Transformed calli were selected on an selection medium containing phosphinothricin (PPT). Transgenic rice plants were regenerated from the PPT-resistant calli. PCR analysis with genomic DNAs from transgenic plants revealed that transgenes are introduced into rice genome.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.100-109
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• 2018

The emergence and dissemination of multidrug-resistant (MDR) Acinetobacter baumannii isolates have been reported worldwide, with most of these possessing the ability to form biofilms. Biofilm formation is an important virulence factor associated with the resistance to disinfection and desiccation. This study examined the genetic basis of antimicrobial resistance mechanisms of biofilm-forming A. baumannii clinical isolates. Imaging and quantification of biofilms were performed by a crystal violet assay and 46 biofilm-forming A. baumannii isolates were selected. Subsequently, 16 isolates belonging to different clones were identified using REP-PCR, and detection of the antimicrobial determinants in the isolates was carried out. The 16 isolates included 9 non-MDR and 7 MDR isolates. The mean biomass $OD_{560}$ values of the non-MDR (0.96) and MDR (1.05) isolates differed but this difference was not significant. In this study, most biofilm-forming MDR A. baumannii isolates contained various antimicrobial resistance determinants ($bla_{OXA-23}$, armA, and mutations of gyrA and parC). On the other hand, most biofilm-forming non-MDR A. baumannii isolates did not contain antimicrobial resistance determinants. These results suggest that there is little correlation between the biofilm-forming ability and antimicrobial susceptibility in A. baumannii isolates. In addition, the emergence of MDR A. baumannii clinical isolates is generally caused by mutations of the genes associated with antimicrobial resistance and/or the acquisition of various antimicrobial resistance determinants.