• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.51-54
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• 2004

This study was conducted to examine differences in shoot regeneration among chrysanthemum cultivars. Leaf explants of chrysanthemum cultivars 'Sulhwa', 'Puma', 'Geummokseo' and 'Sulpoong' were used. Explants cultured on the medium for 2 weeks formed calli at the cut surfaces. Shoots regenerated on MS basal medium supplemented with various concentration combinations of NAA and BAP. Explants were cultured under cool-white fluorescent lamps with a light intensity of $40\mu{Mm}^{-2}$.$s^{-1}$ for 16 $hday^{-1}$, at $25^{\circ}c$ and 70-80% relative humidity. 'Geummokseo' and 'Sulpoong' were the most responsive cultivars in shoot regeneration. Most effective medium for 'Sulhwa' and 'Puma' was MS basal medium supplemented with 10.0 $\mu{M}$ NAA and 5.0 $\mu{M}$ BAP and for 'Geummokseo' MS supplemented with 10.0$\mu{M}$ NAA and 20.0$\mu{M}$ BAP. Regeneration of multiple shoots was observed on MS basal medium supplemented with 1.0$\mu{M}$ or 10.0 $\mu{M}$ NAA and 5.0$\mu{M}$ BAP. High frequency regeneration of adventitious shoots from leaf explants and efficient induction of root from these regenerated shoots were obtained.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.302-310
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• 2016

A study aimed at identifying putative drought responsive genes that confer tolerance to water stress deficit in tea plants was conducted in a 'rain-out shelter' using potted plants. Eighteen months old drought tolerant and susceptible tea cultivars were each separately exposed to water stress or control conditions of 18 or 34% soil moisture content, respectively, for three months. After the treatment period, leaves were harvested from each treatment for isolation of RNA and cDNA synthesis. The cDNA libraries were sequenced on Roche 454 high-throughput pyrosequencing platform to produce 232,853 reads. After quality control, the reads were assembled into 460 long transcripts (contigs). The annotated contigs showed similarity with proteins in the Arabidopsis thaliana proteome. Heat shock proteins (HSP70), superoxide dismutase (SOD), catalase (cat), peroxidase (PoX), calmodulinelike protein (Cam7) and galactinol synthase (Gols4) droughtrelated genes were shown to be regulated differently in tea plants exposed to water stress. HSP70 and SOD were highly expressed in the drought tolerant cultivar relative to the susceptible cultivar under drought conditions. The genes and pathways identified suggest efficient regulation leading to active adaptation as a basal defense response against water stress deficit by tea. The knowledge generated can be further utilized to better understand molecular mechanisms underlying stress tolerance in tea.

• Journal of Plant Biotechnology
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• v.46 no.2
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• pp.97-105
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• 2019

Dehydration Responsive Element Binding (DREB) gene is one of the essential transcription factors plants use for responding to stress conditions including salinity, drought, and cold stress. The purpose of this study was to isolate the full length and characterize the DREB gene from three different genotypes of sugarcane, wild, commercial cultivar, and interspecific hybrid sugarcane. The length of the gene, designated ScDREB was 789 bp, and coding for a putative polypeptide of 262 amino acid residues. Sequences of the gene were submitted to the GenBank database with accession numbers of KX280722.1, KX280721.1, and KX280719.1 for wild sugarcane, commercial cultivar (KPS94-13), and interspecific hybrid (Biotec2), respectively. In silico characterization indicated that the deduced polypeptide contains a putative nuclear localization signal (NLS) sequence, and a conserved AP2/ERF domain of the DREB family, at 82-140 amino residues. Based on multiple sequence alignment, sequences of the gene from the three sugarcane genotypes were classified in the DREB2 group. Gene expression analysis indicated, that ScDREB2 expression pattern in tested sugarcane was up-regulated by salt stress. When the plants were under 100 mM NaCl stress, relative expressions of the gene in leaves was higher than those in roots. In contrast, under 200 mM NaCl stress, relative expressions of the gene in roots was higher than those in leaves. This is the first report on cloning the full length and characterization, of ScDREB2 gene of sugarcane. Results indicate that ScDREB2 is highly responsive to salt stress.

• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.255-261
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• 2001

Vitis vinifera thaumatin-like protein (VVTL1) is a fruit-specific and ripening-related protein in grape. In order to isolate VVTL1-homolog gene and fruit-specific promoter from Campbell cultivar, we isolated a genomic clone containing VVTL1-homolog gene from grape genomic library through plaque hybridization. VVTL1-homolog gene has an intronless genomic structure, which the pattern is matched with those of other PR5 genes such as osmotin and osmotin-like protein genes. Transcription start site was determined by primer extension analysis. The promoter region of VVTL1-homolog gene contains a sequence or structure, especially the location and number of TCA box and ABRE (abscisic acid-responsive element), distinct from other reported plant PR5 genes, though with several known functional elements such as a TATA box and CAAT box. These results suggested that VVTL1-homolog gene may be regulated by a plant hormone, abscisic acid, and one or several stresses such osmotic pressure and pathogen infection. The isolation of fruit-specific promoter may be helpful to breed a genetically modified grape with valuable phenotype or materials in fruits.

• Genomics & Informatics
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• v.19 no.4
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• pp.45.1-45.8
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• 2021

Brassica napus is the third most important oilseed crop in the world; however, in Korea, it is greatly affected by cold stress, limiting seed growth and production. Plants have developed specific stress responses that are generally divided into three categories: cold-stress signaling, transcriptional/post-transcriptional regulation, and stress-response mechanisms. Large numbers of functional and regulatory proteins are involved in these processes when triggered by cold stress. Here, our objective was to investigate the different genetic factors involved in the cold-stress responses of B. napus. Consequently, we treated the Korean B. napus cultivar Naehan at the 4-week stage in cold chambers under different conditions, and RNA and cDNA were obtained. An in silico analysis included 80 cold-responsive genes downloaded from the National Center for Biotechnology Information (NCBI) database. Expression levels were assessed by reverse transcription polymerase chain reaction, and 14 cold-triggered genes were identified under cold-stress conditions. The most significant genes encoded zinc-finger proteins (33.7%), followed by MYB transcription factors (7.5%). In the future, we will select genes appropriate for improving the cold tolerance of B. napus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.288-298
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• 1992

Since the major important factors limiting plant growth and crop productivity are environmental stresses, of which low temperature is the most serious. It has been well known that many physiological processes are alterant in response to the environmental stress. With regard to the relationship between plant hormones and the regulation of chilling tolerance in rice seedlings, the major physiological roles of plant hormones: abscisic acid, ethylene and polyamines are evaluated and discussed in this paper. Rice seedlings were grown in culture solution to examine the effect of such plant hormones on physiological characters related to chilling tolerance and also to compare the different responses among tested cultivars. Intact seedlings about 14 day-old were chilled at conditions of 5$^{\circ}C$ and 80% relative humidity for various period. Cis-(＋)-ABA content was measured by the indirect ELISA technique. Polyamine content and ethylene production in leaves were determined by means of HPLC and GC respectively. Chilling damage of seedlings was evaluated by electrolyte leakage, TTC viability assay or servival test. Our experiment results described here demonstrated the physiological functions of ABA, ethylene, and polyamines related to the regulation of chilling tolerance in rice seedlings. Levels of cis-(＋)-ABA in leaves or xylem sap of rice seedlings increased rapidly in response to 5$^{\circ}C$ treatment. The tolerant cultivars had significant higher level of endogenous ABA than the sensitive ones. The ($\pm$)-ABA pretreatment for 48 h increased the chilling tolerance of the sensitive indica cultivar. One possible function of abscisic acid is the adjustment of plants to avoid chilling-induced water stress. Accumulation of proline and other compatible solutes is assumed to be another factor in the prevention of chilling injuies by abscisic acid. In addition, the expression of ABA-responsive gene is reported in some plants and may be involving in the acclimation to low temperature. Ethylene and its immediate precusor, 1-amincyclopropane-1-carboxylic acid(ACC) increased significantly after 5$^{\circ}C$ treatment. The activity of ACC synthase which converts S-adenosylmethionine (SAM) to ACC enhanced earlier than the increase of ethylene and ACC. Low temperature increased ACC synthase activity, whereas prolonged chilling treatment damaged the conversion of ACC to ethylene. It was shown that application of Ethphon was beneficial to recovering from chilling injury in rice seedlings. However, the physiological functions of chilling-induced ethylene are still unclear. Polyamines are thought to be a potential plant hormone and may be involving in the regulation of chilling response. Results indicated that chilling treatment induced a remarkable increase of polyamines, especially putrescine content in rice seedlings. The relative higher putrescine content was found in chilling-tolerant cultivar and the maximal level of enhanced putrescine in shoot of chilling cultivar(TNG. 67) was about 8 folds of controls at two days after chilling. The accumulation of polyamines may protect membrane structure or buffer ionic imbalance from chilling damage. Stress physiology is a rapidly expanding field. Plant growth regulators that improve tolerance to low temperature may affect stress protein production. The molecular or gene approaches will help us to elucidate the functions of plant hormones related to the regulation of chilling tolerance in plants in the near future.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.355-365
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• 2015

As the global climate has dramatically changed over the past decades, there has been active research on evaluating its effects on food security, which has been recognized as one of the most important issues in the field. In this study, we analyzed the impact of the climate change on the Korean agriculture using meta-analysis methods. Especially, our research focus is on estimating the effect of CO2 concentration and two adaptations (planting-date and cultivar adjustments)on rice that accounts for a larger proportion of the Korean domestic agriculture. Unlike traditional general meta-analysis methods that use summary statistics of effects of interest, meta analysis specific to the agriculture literature was conducted by integrating the data on rice yield that were generated under various CO2 emission scenarios and general circulating models of the 6 collected individual studies. As a modeling approach, the rice yield change ratio was set as the dependent variable and the main and interaction effects of CO2 concentration and adaptation were considered as independent variables in a regression model, As a result, CO2 is estimated to have opposite effects on rice yield depending on whether any of the two adaptations is applied or not; decreasing effect without adaptation and increasing effect with adaptation. In addition, it turns out that the cultivar adjustment has a higher increasing effect on rice yield than the planting-date adjustment. The results of the study are expected to be used as basic quantitative data for establishing responsive polices to the future climate changes.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.67.1-67
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• 2003

Phytophthora blight is a devastating disease of pepper and occurs almost anywhere peppers are grown. Phytophthora blight is caused by Phytophthora capsici and this pathogen can infect every part of the plant by moving inoculum in the soil, by infecting water on surface, by aerial dispersal to sporulating lesions. Management of Phytophthora blight currently relies on cultural practices, crop rotation, and use of selective fungicides. Since these treatments are a short-term management, a classical breeding for development of resistant pepper against the Phytophthora is an alternative. So far some of the resistant cultivars have been on the market, but those are limited regionally and commercially. Therefore, ultimately an elite line resistant against this disease should be developed, if possible, by biotechnology. We have set out a series of work recently in order to develop Phytophthora resistant pepper cultivar. For the first time, the cDNA microarray analysis was peformed using an EST chip that holds around 5000 pepper EST clones to identify genes responsive to Phytophthora infection. Total RNA samples were obtained from Capsicum annuum PI201234 after inoculating P. capsici to roots and soil and exposed to the chip. .Around 900 EST clones were up-regulated and down-regulated depending on the two RNA sample tissues, leaf and root. From those, we have found 55 transcription factors that may be involved in gene regulation of the disease defense mechanism. Further and in detail information will be provided in the poster.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.113-113
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• 2022

Salinity in surface waters is increasing around the world. Many factors, including increased water extraction, poor irrigation management, and sea-level rise, contribute to this change, and posing a threat to plant development and agricultural production. Seeds exposed to high salinity, have a lower probability of germinating and various physiological and biochemical effects. Salinity stress affects more than 20% of agricultural land and about 50% of irrigated land. In the current study, our objective is to identify the salt-tolerant peanut (Arachis hypogaea L.) Korean genotypes under salinity stress. Thus, two-week-old 19 diverse peanut Korean genotypes were exposed to 10 days of salinity (150 mM NaCl) stress. Based on the growth attributes investigation, Baekjung and Ahwon genotypes showed significantly higher shoot lengths compared to control plants. Whereas, the Sinpalwang genotype exhibited a significantly positive response for plant growth and reduced wilting symptoms compared to other genotypes. This study was able to find out peanut tolerant and sensitive genotypes for salt stress. These results may provide a good template for further salt-tolerant peanut cultivar improvement programs. Identified diverse salt-responsive genotypes can be utilized as source material in Korean breeding schemes for peanut crop improvement for salt and other abiotic stress tolerance.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.127-127
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• 2017

Aluminum is the most abundant metallic element in the Earth's crust and considered as the most limiting factor for plant productivity in acidic soils. The inhibition of root growth is recognized as the primary effect of Al toxicity. Seeds of wheat cv. Keumkang (Korean cultivar) were germinated on petridish for 5 days and then transferred hydroponic apparatus which was treated with $0{\mu}M$ $AlCl_3$ (control), $100{\mu}M$ $AlCl_3$ and $150{\mu}M$ $AlCl_3$ for 5 days. The length of roots, shoots and fresh weight of wheat seedlings were decreased under aluminum stress. The concentrations of $K^+$, $Mg^{2+}$ and $Ac^{2+}$ were decreased whereas $Al^{3+}$ and $P_2O_5{^-}$ concentration was increased under aluminum stress. Using confocal microscopy, the fluorescence intensity of aluminum was increased with morin staining. In this study, a proteome analysis was performed to identify proteins, which is responsible to aluminum stress in wheat roots. In 10-day-old seedlings, proteins were extracted from roots and separated by 2-DE, stained by CBB. Using image analysis, a total of 47 differentially expressed protein spots were selected, whereas 19 protein spots were significantly up-regulated such as s-adenosylmethionine, oxalate oxidase, malate dehydrogenase, cysteine synthase, ascorbate peroxidase and 28 protein spots were significantly down-regulated such as heat shock protein 70, o-methytransferase 4, enolase, amylogenin by aluminum stress following protein spots analyzed by LTQ-FTICR mass spectrometry. The results provide the global picture of Al toxicity-induced alterations of protein profiles in wheat roots, and identify the Al toxicity-responsive proteins related to various biological processes that may provide some novel clues about plant Al tolerance.