• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.453-456
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• 2005

This study was carried out to select DNA markers closely linked to brown planthopper (BPH) resistance gene originated from a rice cultivar 'Cheongcheong­byeo'. For the mapping of resistant gene to BPH, a doubled-haploid (DH) population was developed by anther culture of $F_1$ plants from a cross 'Cheongcheong­byeo/Nagdongbyeo'. In BPH bioassay and marker screen­ing for the DH population, the segregation of resistant and susceptible plants to BPH fitted to a 1:1 ratio. A total of 310 RAPDs of 520 markers showed polymorphism in parental survey using 'Cheongcheongbyeo' and 'Nag­dongbyeo'. In the analysis of relationship between BPH resistance and marker pattern for 40 DH lines, the OPE16 produced a specific dominant fragment, 700 bp, which was closely linked with BPH resistance gene of 'Cheong­cheongbyeo'. Based on the linkage analysis using 7 markers, BPH resistance of 'Cheongcheongbyeo' was mapped on chromosome 12, which was closely linked with $OPE16_{700}$ at a distance of 4.6 cM.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.50-56
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• 2007

Barley S-adenosylmethionine synthetase1 gene, which was differentially expressed in seed development of extra early barley, was regulated by the phytohormones and abiotic stresses. In order to identify the regulation regions which were involved in transcriptional control of the phytohormones and abiotic stresses, we isolated 1459 bp fragment of HvSAMS1 gene promoter using genome walking strategy and deletion series were constructed. Deleted upstream fragments(-1459, -1223, -999, -766, -545, -301 bp) were fused to the GUS reporter gene and evaluated via Agrobacterium-mediated transient expression assay. Increased GUS activity of HvSMAS1 promoter -301/GUS construct under each of NaCl, $GA_3$, ABA and ethylene application was found. However, GUS activity was negligible in the leaves transformed with the HvSMAS1 promoter(-1459, -1223, -999, -766 and -545)/GUS constructs. No significant induction of GUS activity was observed for the ethionine and spermidine treatments. In order to locate promoter sequence of the HvSAMS1 gene that was critical for the activation of gene expression, deletion and addition promoter derivatives(+, includes 43 bp of 5' ORF) of the HvSAMS1 gene fused to the GUS reporter gene were applied. The tobacco leaves which harbored the additional HvSAMS1 promoter(-1459+, -1459 to -546, -545+ and -301+)/GUS construct did not significantly induce GUS activity as compared to the HvSAMS1 promoter(-1459, -545 and -301)/GUS constructs under each of NaCl, ABA and $GA_3$ treatment. However, the GUS activity was high in the tobacco leaves which harboring the -211 to -141 regions of the HvSAMS1 promoter. This result suggested that HvSAMS1 gene expression might be regulated by this region(from -211 to -141).

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.241-248
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• 2017

BACKGROUND: RNA interference (RNAi) eliminates or decreases gene expression by disrupting the target mRNA or by interfering with translation. Recently, RNAi technique was applied to generate new crop traits which provide protection against pests. To establish the environmental risk assessment protocol of RNAi LMO in lab scale, we developed dsRNA expression system using E. coli and tested acute oral toxicity assay to honey. METHOD AND RESULTS: The dsRNA expression vector, L4440, was chosen and cloned 240 bp of Snf7 and GFP gene fragment. To develop the maximum dsRNA induction condition in E. coli, we tested induction time, temperature and IPTG concentration in media. To estimate the risk assessment of dsRNA to honey bee, it has been selected and cultured with dsRNA supplement for 48 hours according to OECD guideline. As a result, the optimum condition of dsRNA induction was $37^{\circ}C$, 4 hours and 0.4 mM IPTG concentration and the difference between Snf7 and GFP dsRNA molecules from E. coli was not significant in survival and behavior to honey bee. Furthermore, blast search results indicated that effective match of predicted dsRNA fragments were not existed in honey bee genome. CONCLUSION: In this study, we developed and tested the acute oral toxicity of dsRNA using E. coli expression system to honey bee.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.169-176
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• 2016

Although chemical fertilizers have a quick effect and broad applicability to agricultural fields, they have caused many problems like increasing soil acidity or decreasing soil organic matters. Environmental-friendly agriculture has been attempted in various ways such as organic agriculture, natural farming, low input and sustainable agriculture. The common interest of all environmental-friendly systems is to decrease burden to agricultural environment by low input of agricultural labor and materials. This study was conducted to estimate overwintering capacity and genetic distance among Chinese Milk Vetch (Astragalus sinicus, CMV) collections based on morphological characteristics and AFLP (Amplified fragment length polymorphism) analysis. Furthermore, the effect of CMV as green manure was observed in mix-cultured paddy fields with rice, sesame and sweet-potato. An another objective of this study was also to compare the pattern of weed occurrence in paddy fields with or without CMV and different rice transplanting times. The CMV collected from Paju district in central region of Korea was successively occurring through self-reseeding without artificial management. However, there was no noticeable difference in growth habit between Paju native CMV and introduced CMV from China which is currently used in farm fields. On the basis of multi-dimensional scaling and tree analyses, there are no significant difference of agricultural growth characteristics among Paju and chinese collections only excepting leaf angle and root length. The flowering time of Gurye collection was fast for 1 week as compared to other collections. AFLP that was commonly used for plant classfication, was applied to exam the genetic variation of CMV collections. Total 579 PCR products and 336 polymorphic fragments were generated using 8 primer pairs.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.474-478
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• 2005

This study was conducted to analyze genetic characteristics and to develop the specific marker for Cheju native horse (Coo) at the level of sequence characterized amplified regions (SCARs). We collected blood samples from Cheju native horse and Thoroughbred horse (Th) and obtained genomic DNA from the blood of 50 individuals randomly selected within the breeds. Seven hundred primers were chosen randomly and were used to examin the polymorphism and 40 kinds of primers showed polymorphic RAPD band patterns between two breeds. Thirty primers of them showed horse specific bands. With the primer MG 30, amplified band of 2.0 kb showed the specificity to Cheju native horse (Cnh). Additionally MG 53 detected the thoroughbred horse (Th) specific markers at size of 2.3 kb. As the next, 2.3 kb band from MG 53 was checked with the all individuals from all the breeds of this study, and it maintained the reproducible breed specificity to thoroughbred horse (Th). With this results, 2.3 kb band was cloned into plasmid vector and sequenced bidirectionally from both ends of the cloned fragment. With the obtained sequences 10 nucleotide extended primers including the original arbitray primer were designed as a SCARs primer. Finally, the primer with extended sequence showed the reproducible breed differentiation pattern and it was possible to identify Cheju native horse (Cnh) from other breeds. The SCARs marker 2.3 kb from MG 53 could be used to identify Cheju native horse (Cnh) for not only registration but also horse breeding programe.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.425-430
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• 2015

The objective of the study was to investigate the off-flavor generated from PET water bottles and their caps by using a mass spectrometry-based electronic nose. The ion fragment data obtained from the electronic nose were used for discriminant function analysis (DFA). In the case of increased concentrations of the contamination of water, the off-flavor pattern depended on the discriminant function second score instead of the discriminant function first score. To identify the cause of off-flavor in polyethylene terephthalate (PET) bottled water, the PET bottle and its cap were analyzed by DFA. The results showed that the cap generated more volatile compounds than the bottle or mineral water did. The substances causing the off-flavor were predicted to be 2,4-di-tert-butylphenol (2,4-DTBP), nonanal, and decanal when the main peak of the mass spectrum was compared with the major ion fragments of the electronic nose. Thus, using this method, we could determine whether the PET water bottle was contaminated and whether the off-flavor resulted from contamination of the bottle cap.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.267-272
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• 2011

Several reports indicated that astaxanthin and zeaxanthin have more active anticancer activity than pro-vitamin A carotenes. ${\beta}$-carotene hydroxylase is a key enzyme to synthesize zeaxanthin and astaxanthin in carotenoids biosynthesis pathway. We isolated the ChyB gene encoding ${\beta}$-carotene hydroxylase from tomato leaves. The ChyB gene (1.5Kbp) fragment was cloned into the binary vector and designated to pIG121-ChyB-tom. Agrobacterium-mediated infiltration was used for transient assay in Nicotiana benthamiana. Leaf samples were collected 0, 1, 2, 3 days after infiltration (DAI). RT-PCR result showed that the expression of ${\beta}$-carotene hydroxylase transcripts was not detected in control (0DAI), but its expression was detected after 1 DPI and increased later on. When the activity of ${\beta}$-carotene hydroxylase was measured, the 1,1-diphenyl-pricryl hydrazyl (DPPH) radical scavenging activity (27%) at 2 DAI was significantly higher than that (21%) at 0 DAI. These results indicated that anti-oxidant activity dramatically increased at 2 DAI in tobacco leaves was due to over expression of tomato ${\beta}$-carotene hydroxylase. These results can be the foundation to develop tomato cultivars with high oxy-carotenoids content using the ChyB gene transformation.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.818-827
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• 2010

A full-length cDNA and genomic DNA of a $leucoanthocyanidin$ $dioxygenase$ ($DgLDOX$) gene was isolated from the petals of chrysanthemum 'Argus', and comparative features of the gene among three flower color mutants derived from a gamma-ray mutagenesis were characterized. The cDNA coding region of the gene was 1068 bp and was translated into 356 amino acids accordingly. The genomic DNA size was 1346 bp for 'Argus', while three mutants revealed ranges of 1363 to 1374 bp. A single intron between two coding exons for the $DgLDOX$ gene was found, of which size was 112 bp for 'Argus', but 128 or 137 bp for three flower color mutants, indicating that a genomic insertion in the intron occurred during the gamma-ray mutagenesis. DNA blot analysis revealed the $DgLDOX$ gene presenting as a single copy in the chrysanthemum genome. The $DgLDOX$ gene was expressed in both 'Argus' of light-pink color and two purple color mutants (AM1 and AM3) but had very weak expression in only white color mutant (AM2). The results demonstrated that variations in the flower color of the mutants might be associated with changes in the amino acid moieties in the coding exons or fragment insertions in the intron of the $DgLDOX$ gene, which potentially resulted in less expression of the gene in the white colored mutant.

• Journal of Life Science
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• v.26 no.1
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• pp.75-82
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• 2016

Pseudomonas rhodesiae KK1 has been reported to degrade polycyclic aromatic hydrocarbons (PAHs), such as anthracene, naphthalene, and phenanthrene, which are considered major environmental contaminants. Interestingly, antioxidant genes, including superoxide dismutase, are known to be expressed at different levels in response to environmental contaminants. This study was performed to identify the superoxide dismutase gene in strain KK1, which may be indirectly involved with degradation of PAHs, as well as to investigate the expression pattern of the superoxide dismutase gene in cells grown on different PAHs. Two types of superoxide dismutase genes responsible for the antioxidant defense mechanism, Mn-superoxide dismutase (sodA) and Fe-superoxide dismutase (sodB), were identified in P. rhodesiae KK1. The sodA gene in strain KK1 shared 95% similarity, based on 141 amino acids, with the Mn-sod of P. fluorescens Pf-5. The sodB strain, based on 135 amino acids, shared 99% similarity with the Fe-sod of P. fluorescens Pf-5. Southern hybridization using the sod gene fragment as a probe showed that at least two copies of superoxide dismutase genes exist in strain KK1. RT-PCR analysis revealed that the sodA and sodB genes were more strongly expressed in response to naphthalene and phenanthrene than to anthracene. Interestingly, sodA and sodB activities were revealed to be maintained in cells grown on all of the tested substrates, including glucose.

• Journal of Life Science
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• v.27 no.7
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• pp.746-753
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• 2017

In order to rapidly identify four drums species, Larimichthys polyactis, L. crocea, Atrobucca nibe, and Pseudotolithus elongates, a highly efficient and quick method has been developed using multiplex polymerase chain reaction (PCR) with species-specific primers. Around 1.4 kbp of the mitochondrial COI gene sequences from the four drums species were aligned, and species-specific forward primers were designed, based on the single nucleotide polymorphism (SNP). The optimal conditions for PCR amplification were selected through cross-reactivity, using a gradient PCR method. The PCR results demonstrated species-specific amplification for each species at annealing temperatures between 50 and $62^{\circ}C$. Multiplex species-specific PCR (MSS-PCR) amplification reactions with four pairs of primers were performed for sixteen specimens of each species. MSS-PCR lead to a species-specific amplification of a 1,540 bp fragment in L. polyactis, 1,013 bp in A. nibe, 474 bp in L. crocea, and 182 bp in P. elongates, respectively. The four different sizes of each PCR product can be quickly and easily detected by single gel electrophoresis. The sensitivity of the MSS-PCR of the DNA was up to $0.1ng/{\mu}l$ as a starting concentration for the four different species tested. These results suggest that MSS-PCR, with species-specific primers based on SNP, can be a powerful tool in the rapid identification of the four drums species, L. polyactis, L. crocea, A. nibe, and P. elongates.