• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.17-20
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• 1999

In rice, limited efforts have been made to identify genes by the use of insertional mutagens, especially heterologous transposons such as the maize Ac/Ds. We constructed Ac and gene trap Ds vectors and introduced them into the rice genome by Agrobacterium-mediated transformation. In this report, rice plants that contained single and simple insertions of T-DNA were analyzed in order to evaluate the gene-tagging efficiency. The 3'end of Ds was examined for putative splicing donor sites. As observed in maize, three splice donor sites were identified at the 3'end of the Ds in rice. Nearly 80% of Ds elements wered excised from the original T-DNA sites, when Ac cDNA was expressed under a CaMV 35S promoter. Repetitive ratoon culturing was performed to induce new transpositions of Ds in new plants derived from cuttings. About 30% of the plants carried at least one Ds that underwent secondary transposition in the later cultures. 8% of transposed Ds elements expressed GUS in various tissues of rice panicles. With cloned DNA adjacent to Ds, the genomic complexities of the insertion sites were examined by Southern hybridization. Half of the Ds insertion sites showed simple hybriodization patterns which could be easily utilized to locate the Ds. Our data demonstrate that the Ac/Ds mediated gene trap system could prove an excellent tool for the analysis of functions of genes in rice. We discuss genetic strategies that could be employed in a largee scale mutagenesis using a heterologous Ac/Ds family in rice.

• The Plant Pathology Journal
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• 제39권1호
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• pp.88-107
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• 2023

In the present investigation, bacterial isolates from infected apple trees causing apple canker during winter were studied in the northern Gyeongbuk Province, Korea. The pathogen was identified as Pseudomonas syringae pv. syringae (Pss) through various physiological and biochemical characterization assays such as BIOLOG, gas chromatography of fatty acid methyl esters, and 16S rRNA. Bioassays for the production of phytotoxins were positive for syringopeptin and syringomycin against Bacillus megaterium and Geotrichum candidum, respectively. The polymerase chain reaction (PCR) method enabled the detection of toxin-producing genes, syrB1, and sypB in Pss. The differentiation of strains was performed using LOPAT and GATTa tests. Pss further exhibited ice nucleation activity (INA) at a temperature of -0.7℃, indicating an INA⁺ bacterium. The ice-nucleating temperature was -4.7℃ for a non-treated control (sterilized distilled water), whereas it was -9.6℃ for an INA^- bacterium Escherichia coli TOP10. These methods detected pathogenic strains from apple orchards. Pss might exist in an apple tree during ice injury, and it secretes a toxin that makes leaves yellow and cause canker symptoms. Until now, Korea has not developed antibiotics targeting Pss. Therefore, it is necessary to develop effective disease control to combat Pss in apple orchards. Pathogenicity test on apple leaves and stems showed canker symptoms. The pathogenic bacterium was re-isolated from symptomatic plant tissue and confirmed as original isolates by 16S rRNA. Repetitive element sequence-based PCR and enterobacterial repetitive intergenic consensus PCR primers revealed different genetic profiles within P. syringae pathovars. High antibiotic susceptibility results showed the misreading of mRNA caused by streptomycin and oxytetracycline.

• Carbon letters
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• 제13권3호
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• pp.161-166
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• 2012

Carbon materials were synthesized by pyrolysis from fibers of Corn-straw (Zea mays), Rice-straw (Oryza sativa), Jute-straw (Corchorus capsularis) Bamboo (Bombax bambusa), Bagass (Saccharum officinarum), Cotton (Bombax malabaricum), and Coconut (Cocos nucifera); these materials were characterized by scanning electron microscope, X-ray diffraction (XRD), and Raman spectra. All carbon materials are micro sized with large pores or channel like morphology. The unique complex spongy, porous and channel like structure of Carbon shows a lot of similarity with the original anatomy of the plant fibers used as precursor. Waxy contents like tyloses and pits present on fiber tracheids that were seen in the inherent anatomy disappear after pyrolysis and only the carbon skeleton remained; XRD analysis shows that carbon shows the development of a (002) plane, with the exception of carbon obtained from bamboo, which shows a very crystalline character. Raman studies of all carbon materials showed the presence of G- and D-bands of almost equal intensities, suggesting the presence of graphitic carbon as well as a disordered graphitic structure. Carbon materials possessing lesser density, larger surface area, more graphitic with less of an $sp^3$ carbon contribution, and having pore sizes around $10{\mu}m$ favor hydrogen adsorption. Carbon materials synthesized from bagass meet these requirements most effectively, followed by cotton fiber, which was more effective than the carbon synthesized from the other plant fibers.

• 한국작물학회지
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• 제49권5호
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• pp.434-439
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• 2004

Medicago truncatula is a model plant for molecular genetic studies of legumes and plant-microbe interactions. To accelerate finding of genes that play roles in the early stages of nodulation and stress responses, a trans-genic plant was developed that contains a promoter­reporter fusion. The promoter of rip], a Rhizobium-induced peroxidase gene, was fused to the coding region of $\beta-glucuronidase (GUS)$ gene and inserted into a modified plant transformation vector, pSLJ525YN, in which the bar gene was preserved from the original plasmid but the neomycin phosphotransferase gene was replaced by a polylinker. Transformation of M. truncatula was carried out by vacuum infiltration of young seedlings with Agrobacterium. Despite low survival rates of infiltrated seedlings, three independent transformants were obtained from repeated experiments. Southern blot analyses revealed that 7 of 8 transgenic plants of the T 1 generation contained the bar gene whereas 6 $T_1$ plants contained the GUS gene. These results indicate that vacuum infiltration is an effective method for transformation of M. truncatula. The progeny seeds of the transgenic plants will be useful for mutagenesis and identification of genes that are placed upstream and may influence the expression of rip] in cellular signaling processes including nodulation.

• The Plant Pathology Journal
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• 제31권2호
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• pp.97-107
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• 2015

Alteration of genetic make-up of the isolates and mono-sporidial strains of Tilletia indica causing Karnal bunt (KB) disease in wheat was analyzed using DNA markers and SDS-PAGE. The generation of new variation with different growth characteristics is not a generalized feature and is not only dependant on the original genetic make up of the base isolate/monosporidial strains but also on interaction with host. Host determinant(s) plays a significant role in the generation of variability and the effect is much pronounced in monosporidial strains with narrow genetic base as compared to broad genetic base. The most plausible explanation of genetic variation in presence of host determinant(s) are the recombination of genetic material from two different mycelial/sporidia through sexual mating as well as through parasexual means. The morphological and development dependent variability further suggests that the variation in T. indica strains predominantly derived through the genetic rearrangements.

• Journal of Species Research
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• 제9권3호
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• pp.218-220
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• 2020

A holotype is an element to which the name of a taxon is permanently attached and is key material that facilitates taxonomic research. However, type citation or designation errors due to typographical errors or inadvertent mistakes often exist. When reviewing recently published literature for the type specimens of vascular plants in the herbarium of the National Institute of Biological Resources, we observed that three species, Isoetes laosiensis, Isoetes coreana, and Huperzia jejuensis, had errors, and the actual holotype information and the type descriptions of the protologues did not match. The name Isoetes laosiensis had a collecting number error, while Isoetes coreana and Huperzia jejuensis had collector errors. According to Article 9.2 of the International Code of Nomenclature for algae, fungi, and plants (Shenzhen code), if a holotype designation in the protologue of the name of a taxon is found to contain errors such as collector, collecting number, and illustration errors, the errors are to be corrected. We, therefore, corrected the errors in holotypes of three species, with no alterations made to the intents of the original authors.

• Nuclear Engineering and Technology
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• 제34권6호
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• pp.586-595
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• 2002

The Seismic probabilistic risk assessment (SPRA) or seismic margin assessment (SMA) have been used for the seismic safety evaluation of nuclear power plant structures and equipments. For the SPRA or SMA, the reference response spectrum should be defined. The site-specific median spectrum has been generally used for the seismic fragility analysis of structures and equipments in a Korean nuclear power plant Since the site-specific spectrum has been developed based on the peak ground motion parameter, the site-specific response spectrum does not represent the same probability of exceedance over the entire frequency range of interest. The uniform hazard spectrum is more appropriate to be used in seismic probabilistic risk assessment than the site- specific spectrum. A method for modifying the seismic fragility parameters that are calculated based on the site-specific median spectrum is described. This simple method was developed to incorporate the effects of the uniform hazard spectrum. The seismic fragility parameters of typical NPP components are modified using the uniform hazard spectrum. The modification factor is used to modify the original fragility parameters. An example uniform hazard spectrum is developed using the available seismic hazard data for the Korean nuclear power plant (NPP) site. This uniform hazard spectrum is used for the modification of fragility parameters.

• 한국폐기물자원순환학회지
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• 제35권7호
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• pp.647-652
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• 2018

The emission of nitrogen oxides has a great environmental impact. It leads to Los Angeles type smog, and it recently has attracted attention as a source of ultrafine dust. The main sources of nitrogen oxides are internal combustion engines and industrial boilers. These emission sources are processes that are essential for human industrial activities, so the regulation of original use is impossible. Therefore, special control methods should be applied to reduce NOx emissions into the atmosphere. In this study, we investigated how the supply of ER and urea influences the removal of nitrogen oxides from SRF combustion boilers. Experimental results show that the removal efficiency of nitrogen oxides can be up to 80% under the conditions of ER 2.0 and a urea feed of 0.5 LPM.

• 식물병연구
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• 제29권3호
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• pp.310-315
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• 2023

In May 2021, characteristic soft rot symptoms, including soft, watery, slimy, black rot, wilting, and leaf collapse, were observed on melon plants (Cucumis melo) in Gokseong, Jeollanam-do, Korea. A bacterial strain, designated KNUB-06-21, was isolated from infected plant samples, taxonomically classified, and phylogenetically analyzed using 16S rRNA and housekeeping gene sequencing. Strain KNUB-06-21 was also examined for compound utilization using the API ID 32 GN system and strain KNUB-06-21 was identified as Pectobacterium brasiliense. Subsequent melon stem inoculation studies using strain KNUB-06-21 showed soft rot symptoms similar to field plants. Re-isolated strains shared phenotypic and molecular characteristics with the original P. brasiliense KNUB-06-21 strain. To our knowledge, ours is the first report of P. brasiliense causing melon soft rot disease in Korea.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.30-30
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• 2022

Natural products decursin and decursinol angelate were recently reported as benign fungicides for controlling rice blast. Inspired by the structural similarity of the cumarin compounds and gained hint from the skeletal motifs, we designed and prepared synthetic compounds to increase the natural product efficacy and evaluated their antifungal activities against various plant disease pathogens in vitro. Synthetically prepared compound 4 and 5 indeed suppressed the mycelial growth of B. cinerea, F. oxysporum, P. italicum, and R. quercus-mongolicae. Additionally, compound 5 effectively prevents the growth of C. coccodes and C. parasitica. Furthermore, both 4 and 5 possess better inhibitory activities on spore germination of F. oxysporum and M. oryzae than the natural product decursin. These results suggest that the effect of the lead compound for plant disease protection can be improved by tuning the structure of the original natural product and decursinol chloroacrylates 4 and 5 are candidates for the control of F. oxysporum and M. oryzae.