• Research in Plant Disease
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• v.14 no.2
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• pp.134-137
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• 2008

A strain of Cucumber mosaic virus(CMV) was isolated newly from sweet pepper(Capsicum annuum var. angulosum) showing necrosis with large necrotic spots on fruits and vein banding with malformation on leaf at Cheongdo area in Gyeongsangbukdo. The new strain was designated as a CMV-NP and the shape of virus particles was isometric of 26 nm in diameter from the sweet pepper fruit by Dip method. The strain of CMV-NP was identified genetically by VC/RT-PCR. CMV-NP could infect systemically on the 9 indicator plants including Cucumis sativus, but it could infect locally on Chenopodim amaranticolor and C. quinoa. CMV-NP induced the specific symptoms of necrotic rings on the inoculated and the upper leaves of N. rustica and Tetragonia expansa. On Cucumis sativus, the large chlorotic ring and vein chlorosis were produced on the upper leaves. CMV-NP had no virulence on Datura stramonium.

• The Plant Pathology Journal
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• v.34 no.3
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• pp.199-207
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• 2018

Tomato chlorosis virus (ToCV) is a whitefly-transmitted and phloem-limited crinivirus. In 2013, severe interveinal chlorosis and bronzing on tomato leaves, known symptoms of ToCV infection, were observed in greenhouses in Korea. To identify ToCV infection in symptomatic tomato plants, RT-PCR with ToCV-specific primers was performed on leaf samples collected from 11 tomato cultivating areas where ToCV-like symptoms were observed in 2013 and 2014. About half of samples (45.18%) were confirmed as ToCV-infected, and the complete genome of 10 different isolates were characterized. This is the first report of ToCV occurring in Korea. The phylogenetic relationship and genetic variation among ToCV isolates from Korea and other countries were also analysed. When RNA1 and RNA2 are analysed separately, ToCV isolates were clustered into three groups in phylogenetic trees, and ToCV Korean isolates were confirmed to belong to two groups, which were geographically separated. These results suggested that Korean ToCV isolates originated from two independent origins. However, the RNA1 and RNA2 sequences of the Yeonggwang isolate were confirmed to belong to different groups, which indicated that ToCV RNA1 and RNA2 originated from two different origins and were reassorted in Yeonggwang, which is the intermediate point of two geographically separated groups.

• Journal of Life Science
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• v.8 no.5
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• pp.492-496
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• 1998

Intact measurement of leaf water content was attempted using the transmission of beta radiation. Prior to the experiments, two tested plants, rice and soybean, were grown in 1/5000a wagner pot. The moisure ratio of plant leaves were measured with the beta radiation transmission method using a G-M detector and $^{99}$ Tc as the beta ray sou-rce. Beta radiation transmission showed a tendancy to increase with the passage of time after leaf cutting. However, it showed a tendancy to decrease with water supply for the lack of water. A positive correlation was found between the leaf water content and beta radiation transmission. The mutiple regression analysis about leaf water content was obtained that the coefficient of partial regression for beta radiation transmission was much higher(rice; -0.863, soybean; -0.904) than that for specific leaf area(rice; 0.007, soybean: 0.004).

• Journal of Ginseng Research
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• v.36 no.3
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• pp.298-307
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• 2012

Panax ginseng has been cultivated for centuries, and nine commercial cultivars have been registered in Korea. However, these nine elite cultivars are grown in less than 10% of ginseng fields, and there is no clear authentication system for each cultivar even though their values are higher than those of local landraces. Here, we have developed 19 microsatellite markers using expressed gene sequences and established an authentication system for all nine cultivars. Five cultivars, 'Chunpoong', 'Sunpoong', 'Gumpoong', 'Sunun', and 'Sunone', can each be identified by one cultivar-unique allele, gm47n-a, gm47n-c, gm104-a, gm184-a (or gm129-a), and gm175-c, respectively. 'Yunpoong' can be identified by the co-appearance of gm47n-b and gm129-c. 'Sunhyang' can be distinguished from the other eight cultivars by the co-appearance of gm47n-b, gm129-b, and gm175-a. The two other cultivars, 'Gopoong' and 'Cheongsun', can be identified by their specific combinations of five marker alleles. This marker set was successfully utilized to identify the cultivars among 70 ginseng individuals and to select true F1 hybrid plants between two cultivars. We further analyzed the homogeneity of each cultivar and phylogenetic relationships among cultivars using these markers. This marker system will be useful to the seed industry and for breeding of ginseng.

• Journal of The Korean Society of Clinical Toxicology
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• v.4 no.1
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• pp.78-81
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• 2006

Mad-honey poisoning is mainly brought about by the honey imported from Napal, Turkey, Brazil and other parts of Europe. This mad honey is extracted from Ericaceae plants of Rhododendron species and contains grayanotoxins that causes poisoning. These toxic compounds exert a specific stimulatory action on membrane permeability to Na+ions in various excitable tissues and cause depolarization of cell membranes. The toxic effects of grayanotoxins contained honey are mainly cardiovascular disturbances with bradycardia, cardiac arrhythmia, hypotension. There are Other symptoms like nausea, vomiting, salivation, dizziness, weakness and loss of consciousness. The precise amount for a toxic dose is not known. In general the severity of the honey poisoning depends on the amount ingested. Two cases of mad-honey poisoning are described here. Both patients showed bradycardia and arterial hypotension after ingestion of honey which was brought from Nepal. They were recovered fully within 24 hours after administration of fluids and atropine sulphate.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.04a
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• pp.65-73
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• 2007

The objective of this study is to understand how regulatory mechanisms respond to sugar status for more efficient carbon utilization and source-sink regulation in plants. So, we need to identify and characterize many components of sugar-response pathways for a better understanding of sugar responses. For this end, genes responding change of sugar status were screened using Arabidpsis cDNA arrays, and confirmed thirty-six genes to be regulated by sucrose supply in detached leaves by RNA blot analysis. Eleven of them encoding proteins for amino acid metabolism and carbohydrate metabolism were repressed by sugars. The remaining genes induced by sugar supply were for protein synthesis including ribosomal proteins and elongation factors. Among them, I focused on three hydrolase genes encoding putative $\beta$-galactosidase, $\beta$-xylosidase, and $\beta$-glucosidase that were transcriptionally induced in sugar starvation. Homology search indicated that these enzymes were involved in hydrolysis of cell wall polysaccharides. In addition to my results, recent transcriptome analysis suggested multiple genes for cell wall degradation were induced by sugar starvation. Thus, I hypothesized that enzyme for cell wall degradation were synthesized and secreted to hydrolyze cell wall polysaccharides producing carbon source under sugar-starved conditions. In fact, the enzymatic activities of these three enzymes increased in culture medium of Arabidopsis suspension cells under sugar starvation. The $\beta$-galactosidase encoded by At5g56870 was identified as a secretory protein in culture medium of suspension cells by mass spectrometry analysis. This protein was specifically detected under sugar-starved condition with a specific antibody. Induction of these genes was repressed in suspension cells grown with galactose, xylose and glucose as well as with sucrose. In planta, expression of the genes and protein accumulation were detected when photosynthesis was inhibited. Glycosyl hydrolase activity against galactan also increased during sugar starvation. Further, contents of cell wall polysaccharides especially pectin and hemicellulose were markedly decreased associating with sugar starvation in detached leaves. The amount of monosaccharide in pectin and hemicellulose in detached leaves decreased in response to sugar starvation. These results supported my idea that cell wall has one of function to supply carbon source in addition to determination of cell shape and physical support of plant bodies.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.189-189
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• 2017

Salinity is one of the major abiotic stresses that severely affect crop production throughout the world; especially rice plant which is generally categorized as a typical glycophyte as it cannot grow in the presence of salinity. Phenotypic resistance of salinity is expressed as the ability to survive and grow in a salinity condition. Salinity resistance has, at least implicitly, been treated as a single trait. Physiological studies of rice suggest that a range of characteristics (such as low shoot sodium concentration, compartmentation of salt in older rather than younger leaves, high potassium concentration, high $K^+/Na^+$ ratio, high biomass and plant vigour) would increase the ability of the plant to cope with salinity. Criteria for evaluating and screening salinity tolerance in crop plants vary depending on the level and duration of salt stress and the plant developmental stage. Plant growth responses to salinity vary with plant life cycle; critical stages sensitive to salinity are germination, seedling establishment and flowering. We have established a standard protocol to evaluate large rice germplasms for overall performance based on specific physiological traits for salt tolerance at seedling stage. This protocol will help in identifying germplasms which can perform better in the presence of different salinity treatments based on single trait and also combination of different physiological traits. The salt tolerant germplasm can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.224-224
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• 2017

In plants, cysteine(Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur containing secondary products. Cys formation is involved in the consecutive two reactions using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast and mitochondria. OASTL is able to produce mimosine with 3-hydroxy-4-pyridone (3H4P) in lieu of $H_2S$ for Cys. In this report, we describe the first time cloning, purification and characterization of cytosolic(cy)OASTL from M. pudica and its expression in Escherichia coli and try to find out the cross link between this OASTL and the mimosine formation and to elucidate the metabolic role of cy-OASTL in M. pudica. The purified recombinant protein was 34.7 KDa. The optimum reaction pH and temperature was 6.5 and $50^{\circ}C$, respectively. The Michaelis constant (Km) and the Vmax value of the enzyme was $252{\pm}25{\mu}M$ and $57{\pm}3{\mu}M\;cysteine\;min^{-1}\;{\mu}g\;protein^{-1}$ for sulfide and $159{\pm}21{\mu}M$ and $58{\pm}2.4{\mu}M\;cysteine\;min^{-1}\;{\mu}g\;protein^{-1}$ for OAS subsequently. After cleaving the His-tag, we tried to observe cy-OASTL to form mimosine with appropriate substrate but it was not successful. It may be concluded that cy-OASTL of the present study is only Cys specific, not mimosine.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.195-207
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• 2020

In Korea, specific thermal elements such as annual mean temperature (AMT) 13℃, 14℃, and Kira's coldness index (CI) -10℃, have been suggested about the northernmost distribution of the warm-temperate evergreen broad-leaved forest zone. We reviewed the relationship between three thermal elements and the actual distribution of evergreen broad-leaved woody plants or its communities. Thiessen and Kriging method using point-data calibrated by seasonal lapse rate according to altitude were utilized for the spatial distribution pattern analysis. Several phytoclimatic maps were also produced in order to compare different thermal values. We identified that the AMT 13℃ was the best thermal element to demarcate the northern limit of the warm-temperate forest zone. Its area was estimated ca. 20,334 ㎢ and larger than those of other thermal elements. We concluded that an indirectly fabricated index i.e. CI -10℃ is useless and it was enough for a direct value of AMT 13℃ to represent the northern-limit distribution of warm-temperate forest zone, at least in Korea. Further researches on the reciprocity between floristic regions and phytoclimate zones are raised.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.233-239
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• 2016

The purpose of this study is to investigate the response of the soil mesofauna and ground-dwelling arthropods to vegetation structure and composition in a mountain pasture. The pasture mainly comprised five types of plant communities; Agrostis alba - Phleum pratense community, Poa pratensis community, Festuca ovina community, Rumex acetosella community, and the shrub assemblage comprised Spiraea miyabei-Spiraea salicifolia community. Soil chemical properties including the pH, EC and nutrient levels were influenced by plant communities. Plant-specific responses were observed for bacteria-feeding and plant-feeding soil nematodes. Collembola and Oribatida having the same feeding habit were influenced differently by plants. nMDS showed that the community of ground-dwelling arthropods were separated by vegetation types. Species numbers of arthropods were different among different plant communities. Our results indicate that vegetation structure and composition can influence both abundance of diversity of terrestrial fauna.