• Journal of Applied Biological Chemistry
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• 제51권2호
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• pp.50-56
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• 2008

As one way to approach to cold defense mechanism in plants, we previously identified the gene for protein-tyrosine phosphatase (CaTPP1) from hot pepper (Capsicum annuum) using cDNA microarray analysis coupled with Northern blot analysis. We showed that the CaTPP1 gene was strongly induced by cold, drought, salt and ABA stresses. The CaTPP1 gene was engineered under control of CaMV 35S promoter for constitutive expression in transgenic tobacco plants by Agrobacterium-mediated transformation. The resulting CaTPP1 transgenic tobacco plants showed significantly increased cold stress resistance. It also appeared that some of the transgenic tobacco plants showed increased drought tolerance. The CaTPP1 transgenic plants showed no visible phenotypic alteration compared to wild type plants. These results showed the involvement of protein tyrosine phosphatase in tolerance of abiotic stresses including cold and drought stress.

• Journal of Plant Biotechnology
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• 제4권2호
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• pp.53-58
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• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.149-155
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• 2013

Heterologous expression of a putative $K^+/H^+$ antiporter of Streptomyces coelicolor A3(2) (designated as sha4) in E. coli and Streptomyces hygroscopicus JCM4427 showed enhanced tolerance to $K^+$ stress, acidic-pH shock, and/or geldanamycin production under $K^+$ stress. In a series of $K^+$ extrusion experiments with sha4-carrying E. coli deficient in the $K^+/H^+$ antiporter, a restoration of impaired $K^+$ extrusion activity was observed. Based on this, it was concluded that sha4 was a true $K^+/H^+$ antiporter. In different sets of experiments, the sha4-carrying E. coli showed significantly improved tolerances to $K^+$ stresses and acidic-pH shock, whereas sha4-carrying S. hygroscopicus showed an improvement in $K^+$ stress tolerance only. The sha4-carrying S. hygroscopicus showed much higher geldanamycin productivity than the control under $K^+$ stress condition. In another set of experiments with a production medium, the secretion of geldanamycin was also significantly enhanced by the expression of sha4.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.173-179
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• 2003

The combination of a radiation technique with an in vitro culture system was appiled to develop submergence tolerant rice. The 3,000 $M_3$ lines with an average 80 percent of fertile grain were utilized for the selection of submergence tolerance. Salt tolerant lines were selected based on high plant height, root length and root number after submergence in plastic pots. Of the lines tested, the tolerant line (403-6) showed a dramatic difference in morphological traits under submergence compared to its original variety (Dongjinbyeo). It was suggested that genetic variations between the original variety and $M_3$-403-6 did exist. The levels of $\alpha$-amylase and alcohol dehydrogenase activities were significantly increased in the mutant line compared to its original variety. The mutant with greater tolerance showed less electrolyte leakage indicating a greater membrane integrity and better survival. Also, this line was much more resistant to a salt stress of $1.25\%$ than the original variety. The proline level of the line was significantly (p<0.01> higher than that of the original variety. The relationships between the inhibition of growth caused by stress and the physiological changes in the plant cell were discussed.

• 아시안잔디학회지
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• 제16권2호
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• pp.75-83
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• 2002

The back-filled soil of the New Incheon International Airport construction site was reclaimed with sea sand in near the Young-Jong island. The primary study was carried out from August 1993 to June 1997 to study soil amendment and to select salt resistance turfgrass species. This study dealt with low maintenance area that included most part of open space of airport site. The second experiment, from October 1996 to August 1998, focused on soil amendment and selection of turfgrass species for alongside runway where turf area was maintained. Through two previous studies, propagation methods with zoysiagrass were tested for alongside runway and surrounding areas at 1998. The study of construction methods with zoysiagrass, vegetative propagation showed better results on visual quality and cover rating compare with seeding propagation. However, significant different between vegetative and seeding propagation was not showed on visual quality and drought tolerance after one year of plot establishment. The cover rating by seeding construction methods reached in excess of 70% of limitation suggested by the Incheon International Airport Cooperation. Zoysia net and sprigging net methods were the most suitable where there requires rapid and high rate of ground cover. Seeding propagation should be acceptable to obtain a resonable cover rating where there allows relatively longer period of completion. Therefore, it should be possible to attain a proper rating of ground cover on the site of open space, alongside runway or areas similar to the New Incheon International Airport which is being built on dredged seashore sand. However, the methods of soil amendment, selecting salt tolerance species, and proper construction procedure should be considered at the a time.

• 한국작물학회지
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• 제47권6호
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• pp.422-426
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• 2002

비염해지인 육답에 대한 간척답의 염농도가 0.2%, 0.3%, 0.4%인 지역에서 수도 생육 및 수량반응을 비교 검토하여 수도의 내염성 및 품종육성의 기초자료를 얻고자 일반계 품종 6품종 통일형 5품종을 공시한 결과는 다음과 같다. 1. 출수지연 정도는 육답 대비 0.2%포장에서는 일반계 품종은 2일, 통일형품종은 3일이 지연되었고, 0.3%포장에서는 일반계품종이 5일, 통일형품종이 8일, 그리고 0.4%포장에서는 각각 10일과 13일이 지연되었다. 2. 간장은 일반계품종이 13-39%, 통일형품종이 12-35% 감소율을 보였고, 수수는 일반계품종이 16-40%, 통일형품종이 14-35% 감소율을 나타내어 간장 및 수수의 감소율은 일반계 품종이 더 심하였다. 3. 수당립수는 일반계품종과 통일형품종 공히 10-40%의 감수율을 보였으나, 등숙율은 일반계품종 20-48%와 통일형품종 19-52%의 감수율을 보여, 통일형품종이 더 심하였다. 4. 천립중은 23% 이내의 비교적 적은 감소율을 보인 반면, 수량은 일반계 품종은 20-62%, 통일형품종은 25-68%의 감소율을 보여 통일형품종이 더 컸다.

• Journal of Plant Biotechnology
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• 제30권4호
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• pp.323-328
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• 2003

토양 내의 고농도의 염은 심각한 환경스트레스 중의 하나로 농작물의 생산을 감소시킨다. 식물은 염 스트레스로부터 벗어나기 위하여 많은 단백질을 합성한다든지 유전자들의 발현을 조절하는 등 여러 가지 생리, 생화학적인 변화를 일으킨다. 퉁퉁마디는 우리나라에 자생하는 염생식물로 갯벌과 염전주위에서 생육한다. 퉁퉁마디의 생화학적, 분자생물학적 내염성 기구를 이해하기 위하여 differential display방법으로 NaCl에 의하여 발현이 증가되는 cDNA들을 분리하였다. 본 연구에서는 그 중 하나인 ShADL의 특성을 조사하였다. ShADL은fructose-1, 6-bisphosphate aldolase와 높은 유사성을 보였다. 이 유전자는 1293bp길이에 359개의 아미노산으로 구성된 open reading frame을 포함하고 있으며, 이로부터 추정되는 분자량은 39 kDa이었다. ShADL단백질은 애기장대의 aldolase와 86％의 높은 유사성을 나타내었으며 같은 염생식물인 com-mon ice plant의 adolase와는 78％의 유사성을 보였다. Northern 분석결과, ShADL 유전자는 NaCl의 농도가 증가함에 따라 발현량이 급격히 증가하는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.415-418
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• 2000

Productivity of a rice plant is greatly influenced by salt stress. One of the ways to achieve tolerance to salinity is to transfer genes encoding protective enzymes from other organisms, such as microorganisms. The bacterial gene, mtlD, which encodes mannitol-1-phosphate dehydrogenase (Mtl-DH), was introduced to the cytosol of a rice plant by an imbibition technique to overproduce mannitol. The germination and survival rate of the imbibed rice seeds were markedly increased by transferring the mtlD gene when it was delivered in either a pBIN19 or pBmin binary vector. When a polymerase chain reaction was performed with the genomic DNAs of the imbibed rice leaves as a template and with mtlD-specific primers, several lines were shown to contain an exogenous mtlD DNA. However, a reverse transcription (RT)-PCR analysis revealed that not all of them showed an expression of this foreign gene. This paper demonstrates that the growth and germination of rice plants transiently transformed with the bacterial gene, mtlD, are enhanced and these enhancements may have resulted from the experssion of the mtlD gene. The imbibition method empolyed in this study fulfills the requirements for testing the function of such a putative gene in vivo prior to the production of a stable transgenic plant.

• 한국초지조사료학회지
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• 제38권3호
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• pp.190-195
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• 2018

Cold, salt and heat are the most critical factors that restrict full genetic potential, growth and development of crops globally. However, clarification of genes expression and regulation is a fundamental approach to understanding the adaptive response of plants under unfavorable environments. In this study, we applied an annealing control primer (ACP) based on the GeneFishing approach to identify differentially expressed genes (DEGs) in Italian ryegrass (cv. Kowinearly) leaves under cold, salt and heat stresses. Two-week-old seedlings were exposed to cold ($4^{\circ}C$), salt (NaCl 200 mM) and heat ($42^{\circ}C$) treatments for six hours. A total 8 differentially expressed genes were isolated from ryegrass leaves. These genes were sequenced then identified and validated using the National Center for Biotechnology Information (NCBI) database. We identified several promising genes encoding light harvesting chlorophyll a/b binding protein, alpha-glactosidase b, chromosome 3B, elongation factor 1-alpha, FLbaf106f03, Lolium multiflorum plastid, complete genome, translation initiation factor SUI1, and glyceraldehyde-3-phosphate dehydrogenase. These genes were potentially involved in photosynthesis, plant development, protein synthesis and abiotic stress tolerance in plants. However, this study provides new insight regarding molecular information about several genes in response to multiple abiotic stresses. Additionally, these genes may be useful for enhancement of abiotic stress tolerance in fodder crops as well a crop improvement under unfavorable environmental conditions.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.771-780
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• 2014

A putative lipolytic enzyme gene, named as est9x, was obtained from a marine microbial metagenome of the South China Sea. Sequence analysis showed that Est9X shares lower than 27% sequence identities with the characterized lipolytic enzymes, but possesses a catalytic triad highly conserved in lipolytic enzymes of the ${\alpha}/{\beta}$ hydrolase superfamily. By phylogenetic tree construction, Est9X was grouped into a new lipase/esterase family. To understand Est9X protein in depth, it was recombinantly expressed, purified, and biochemically characterized. Within potential hydrolytic activities, only lipase/esterase activity was detected for Est9X, confirming its identity as a lipolytic enzyme. When using p-nitrophenol esters with varying lengths of fatty acid as substrates, Est9X exhibited the highest activity to the C2 substrate, indicating it is an esterase. The optimal activity of Est9X occurred at a temperature of $65^{\cric}C$, and Est9X was pretty stable below the optimum temperature. Distinguished from other salt-tolerant esterases, Est9X's activity was tolerant to and even promoted by as high as 4 M NaCl. Our results imply that Est9X is a unique esterase and could be a potential candidate for industrial application under extreme conditions.