• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.327-333
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• 2021

The two main hypotheses that explain why invasive alien plants successfully colonize new environments are: 1) invasive alien plants are functionally different from native plants in a community, and 2) the plants can adapt well to new environments because they are functionally similar to native plants. The present study investigated the functional traits of naturalized alien herbaceous plants and their native neighbors in a riparian park area near the Hapcheon-Changyeong weir along the Nakdong River to determine which of the two hypotheses applied to the study area. According to the results, leaf functional traits, such as leaf area, specific leaf area, leaf thickness, leaf dry matter content, leaf nitrogen content, and leaf carbon content differed between naturalized alien and native plants, which could be attributed to the higher leaf nitrogen contents in naturalized alien plants than in native plants. The high leaf nitrogen contents are associated with high photosynthetic rates, which lead to effective resource use and rapid growth; therefore, naturalized alien plants growing in the study area were considered to have such functional traits. The results of the present study support the hypothesis that the successful establishment of invasive alien plants is attributed to the functional trait differences between invasive and native plants.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.3
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• pp.113-119
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• 2018

The probabilistic seismic safety assessment is one of the methodology to evaluate the seismic safety of the nuclear power plants. The site characteristics of the nuclear power plant should be reflected when evaluating the seismic safety of the nuclear power plant. The Korea seismic characteristics are strong in high frequency region and may be different from NRC Regulatory Guide 1.60, which is the design spectrum of nuclear power plants. In this study, seismic response of a nuclear power plant structure by Pohang earthquake (2017.11.15. (KST)) is investigated. The Pohang earthquake measured at the Cheongsong seismic observation station (CHS) is scaled to the peak ground acceleration (PGA) of 0.2 g and the seismic acceleration time history curve corresponding to the design spectrum is created. A nuclear power plant of the containment building and the auxiliary buildings are modeled using OPENSEES to analyze the seismic response of the Pohang earthquake. The seismic behavior of the nuclear power plant due to the Pohang earthquake is investigated. And the seismic performances of the equipment of a nuclear power plant are evaluated by the HCLPF. As a result, the seismic safety evaluation of nuclear power plants should be evaluated based on site-specific characteristics of nuclear power plants.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.325-328
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• 2001

Gelatin particle agglutination test (GPAT) was used to detect Cymbidum mosaic virus (CymMV) in Cattleya plants. Gelatin particles were coated with purified anti-CymMV immunoglobulin of 25-100 $\mu\textrm{g}$/ml and were subjected to several different concentrations of purified CyMfV as well as varying dilutions of orchid leaf extracts. The GPAT detected purified CymMV up to a minimum concentration of 10 $\mu\textrm{g}$/ml. CymMV was detected from crude sap extract of infected Cattleya leaves and roots up to 1:51,200 and 1:25,600 dilutions, respectively. However, the optimum range of leaf and root sap dilutions was between 50-100. Non-specific reactions were not encountered from any of the healthy orchid plants tested. The entire GPAT process was completed within 2-3 hours. This test was found to be very useful for the detection of CymMV in orchids because it is sensitive, economical, and easy to perform.

• Journal of Plant Biology
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• v.33 no.2
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• pp.119-126
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• 1990

The content of canavanine was measured and analyzed in leaves, roots and xylem exudate of Canavalia lneata. In non-nodulated plants, the cotyledons were removed after a week of sowing and the plants were grown for 3 weeks. The quantity of canavanine measured by canavanine specific-PCAF colorimetric assay was 9-10 $\mu$mol/g fresh wt. in leaves, 5-6 $\mu$mol/g fresh wt. in roots, and 0.3-0.5 $\mu$mol/ml in xylem exudate. When free amino acids of leaves, roots, and xylem exudate were analysed by HPLC, the relative proportion of asparagine plus glycine was the highest and canavanine was high secondarily. And the relative proportion of canavanine among total free amino acids was 30-35% in leaves and roots, and 12-13% in xylem exudate. In non-nodulated plants grown for 8 weeks, the canavanine content of each part was similar to that of 3-week-old plants. By the formation of nodules, the canavanine content of leaves, roots, xylem exudate, and nodules decreased apparently. In xylem exduate, the nitrogenous compounds were also analyzed. The relative contents of NO3-, free amino acids, and ureides(allantoin and allantoic acid) were 60-80%, 20-30%, and 5%, respectively. From these results, it can be assumed that canavanine is synthesized in the root of plant and nodulation affects the canavanine content. It is obvious that canavanine is considered one of the reduced-N forms transported via xylem.

• Korean Journal of Plant Resources
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• v.21 no.2
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• pp.139-143
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• 2008

Enzyme activity and expression of cytochrome P450 gene involved in the pathway of capsidiol biosynthesis were compared in five different solanaceae plants such as red pepper, green pepper, tobacco, potato and egg plant. Base on genomic DNA and/or RT-PCR results, four solanaceae plants such as red pepper, green pepper, tobacco and egg plant possess P450 gene in the genome and specifically expressed by elicitor treatment. However, potato was appeared to have neither P450 nor cyclase gene in the genome. P450 genes did not show any expression in the plants under normal condition, but showed highly specific expression under elicitation condition in various organs and tissue such as leaf, root, stem and culture cells.

• Molecules and Cells
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• v.25 no.2
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• pp.258-264
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• 2008

Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.

• Mycobiology
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• v.29 no.1
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• pp.48-53
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• 2001

Plants have the ability to acquire an enhanced level of resistance to pathogen attack after being exposed to specific biotic stimuli. To obtain plant growth-promoting rhizobacteria inducing resistance against cucumber anthracnose by Colletotrichum orbiculare, more than 800 strains of rhizobacteria were screened in the greenhouse. Among these strains, Bacillus amyloliquefaciens solate EXTN-1 showed significant disease control efficacy on the plants. Induction of pathogenesis-related(PR-la) gene expression by EXTN-1 was assessed using tobacco plants transformed with PR-1a::$\beta$-glucuronidase(GUS) construct. GUS activities of tobacco treated with EXTN-1 and salicylic acid-treated transgenic tobacco were significantly higher than those of tobacco plants with other treatments. Gene expression analyses indicated that EXTN-1 induces the accumulation of defense-related genes of tobacco. The results showed that some defense genes are expressed by the treatment with EXTN-1 suggesting the similar resistance mechanism by salicylic acid.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.969-980
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• 2017

Purpose: The purpose of this study was to estimate the lifetime, and verify the target lifetime at steady state temperature, of communication cable jackets used in nuclear power plants. Method: This study was completed according to test and analysis methods required by international standards. After measuring the residual elongation(%) of specimens at specific points in time with the accelerated degradation test, average failure time of each temperature was computed. Thus, the activation energy could be derived by applying the temperature-Arrhenius law to estimate cable jacket lifetime at steady state temperature. Results: The cable jacket lifetime was estimated as 363.8 years assuming a normal nuclear power plant operating temperature of $90^{\circ}C$. Conclusion: To ascertain stable operating conditions for a nuclear power plant, accelerated degradation tests were performed according to the Arrhenius law for components of the nuclear power plants. The lifetime was estimated from the degradation data collected during the accelerated degradation test.

• The Plant Pathology Journal
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• v.29 no.2
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• pp.201-208
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• 2013

Drought stress is one of the major yield affecting factor for pepper plant. The effects of PGPRs were analyzed in relation with drought resistance. The PGPRs inoculated pepper plants tolerate the drought stress and survived as compared to non-inoculated pepper plants that died after 15 days of drought stress. Variations in protein and RNA accumulation patterns of inoculated and non-inoculated pepper plants subjected to drought conditions for 10 days were confirmed by two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and differential display PCR (DD-PCR), respectively. A total of six differentially expressed stress proteins were identified in the treated pepper plants by 2D-PAGE. Among the stress proteins, specific genes of Cadhn, VA, sHSP and CaPR-10 showed more than a 1.5-fold expressed in amount in B. licheniformis K11-treated drought pepper compared to untreated drought pepper. The changes in proteins and gene expression patterns were attributed to the B. licheniformis K11. Accordingly, auxin and ACC deaminase producing PGPR B. licheniformis K11 could reduce drought stress in drought affected regions without the need for overusing agrochemicals and chemical fertilizer. These results will contribute to the development of a microbial agent for organic farming by PGPR.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.370-378
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• 2010

This review describes the stratagies of development of virus-resistant Alstroemeria plants using the genetic modification system. Despite of increasing of its importance in cut flower market, improvements of some horticultuirally important traits such as fragrance, long vase-life, virus resistance and tolerance against abiotic stresses are lack of the breeding program in Alstroemeria. Of these traits, virus-resistance is quite difficult to develop in Alstroemeria plants due to the limitations of genetic variation in the existed germplasm. To extend the genetic variation, plant biotechnological techniques such as genetic transformation and tissue culture should be combined to develop virus-resistant line in Alstroemeria. In this review, several strategies for the generation of virus-resistance by using natural resistance genes, pathogen-derived genes and other sources including pathogen-derived proteins, virus-specific antibodies and ribosome-inactivating proteins are presented. Also, brief histories of breeding, tissue culture, and transformation system in Alstroemeria plants are described to inderstand of the application of transgenic approach for the development of virus-resistance in Alstroemeria species.