• Journal of Plant Biotechnology
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• 제6권1호
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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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• 제43권3호
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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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• 제46권2호
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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.

• 식물조직배양학회지
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• 제28권5호
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• pp.255-261
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• 2001

VVTL1은 포도 과육에서 특이적으로 다량 발현되는, PR5 계열의 thaumatin과 높은 상동성을 나타내는 단백질로서, 품종에 따라 염기서열의 차이를 나타낸다고 알려져 있다. 현재까지 포도의 VVTL1에 대해서 몇몇 연구가 진행되었지만, 우리나라에서 가장 많이 재배되는 품종인 캠벨에서는 전혀 이루어지지 않았다. 본 연구에서는 캠벨 품종으로부터 VVTL1-homolog 유전자의 게놈 DNA를 분리하여, 염기서열을 분석하였다. VVTL1-homolog 유전자는 일반적으로 PR5 유전자의 구조와 동일한 구조인, intron이 없는 하나의 exon으로만 구성되어 있었다. 염기서열로부터 추론된 VVTL1-homolog 단백질의 아미노산 서열은 VVTL1을 비롯한 다른 품종의 포도에서 분리된 TLP와는 달리 염기성의 등전점을 가지고 있었다. Primer extension 분석을 통해 전사개시 부위를 결정하였고, promoter영역을 포함하는 5'upstream 지역에 전사에 중요한 TATA box (4개)와 CAAT box (1개)가 존재하였으나, 이들의 위치와 수는 다른 PR5 유전자의 promoter와는 다랐다. 이러한 연구결과는 VVTL1-homolog 유전자의 발현이 과육 성숙과정동안 abscisic acid와 스트레스 또는 자극에 의해 발현이 유도되고 있음을 제시해준다. 포도 과육특이발현 promoter인 VVTL1-homolog 유전자의 promoter 분리는, 유전자의 도입에 의해 유용형질을 과육에 나타내는 포도품종을 개발하고자 할 때 효율적으로 사용될 수 있을 것으로 사료된다.

• Genomics & Informatics
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• 제19권4호
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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.

• 한국작물학회지
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• 제37권3호
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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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• 제26권2호
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• pp.355-365
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• 2015

지난 수 십년간 전 지구적인 기후가 극적으로 변화함에 따라 가장 중요한 문제 중 하나로 인식되고 있는 식량 안보에 대하여 기후 변화의 영향을 평가하는 연구가 활발하게 진행되어 왔다. 본 연구에서는 메타분석을 이용하여 기후변화가 국내 농업에 미치는 영향을 분석하였다. 특히, 국내 농업에서 큰 비중을 차지하는 쌀에 대하여 이산화탄소 농도와 두 적응방안(파종시기 변경과 품종 변경)에 대한 효과를 추정하였다. 관심있는 효과에 대한 요약통계량을 이용하는 기존의 일반적인 메타분석 방법과는 달리, 다양한 온실가스 배출 시나리오와 대순환 모형을 사용하여 쌀 생산량을 예측한 6개의 개별 연구로부터 자료를 통합하여 메타분석을 수행하였다. 모델링 접근법으로써 쌀 생산량의 변화율을 종속변수로 설정하고, 이산화탄소 농도와 적응방안의 주 효과와 상호 작용 효과를 독립변수로 설정하여 회귀분석 실시하였다. 결과적으로 적응방안이 고려되지 않을 경우 이산화탄소 농도의 증가는 쌀 생산량을 감소시키나, 적응방안이 고려된다면 이산화탄소 농도의 증가는 쌀 생산량을 증가시키는 것으로 나타났다. 추가로 파종시기 변경 방안보다 품종 변경 방안이 쌀 생산량을 더 증가시키는 것을 알 수 있었다. 본 연구 결과는 향후 기후변화 대응책을 수립하는데 정량적 자료로 활용될 것으로 기대된다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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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.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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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.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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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.