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        검색결과 68

        21.
        2015.07 서비스 종료(열람 제한)
        Grain color distinguishes between the pigmentation of the outer layer of the kernel. It is known that environmental factors affects the production of anthocyanins and abiotic stresses like high light intensity, low temperature, high salinity and/or drought stress, and others increase their amounts. After 7 days the germination rate between yellow and dark-purple seeds were almost the same with and without stress (100% yellow seeds under stress and without stress germinated, 93.3% under stress and 96.6% without stress of purple seeds germinated), even though at the final stage the germination was almost the same, we can conclude base on our observations that the germination takes place at a different rate. We think that this might be related to the seed color, since the germination of purple seeds under salt stress started earlier than the yellow ones, until both reached the same point. The antioxidant activity was higher in seedlings from dark-purple seeds than the yellow ones, and they were higher under salt stress than without it, supporting our hypothesis that the purple color in wheat seeds works as a protection under salt stress. Furthermore, the qRT-pCR showed that some genes related to the flavonoid pathway were expressed or had more expression in the seedlings from dark-purple seeds than yellow ones.
        22.
        2015.07 서비스 종료(열람 제한)
        Crops are exposed to various environmental stresses. These have been affecting the growth of crops, resulting in the severe loss of agronomic production in many countries. Therefore, development of new varieties of resistant crops is required to assure the desired productivity of crops in stress conditions. In this study, a putatively stress-related gene BrTSR53 was isolated from Brassica rapa. The BrTSR53 is 481 bp long and contains ORF region of 234 bp. The expression of BrTSR53 was determined by quantitative real-time PCR analysis. After 3 hr, the highest quantities of mRNA were revealed in cold and salt stress treatments. In drought stress treatments, there was the highest expression after 36 hr. Therefore, it was confirmed that the ORF in BrTSR53 should be a gene that confer increased resistance to B. rapa growing in different stress conditions. The ORF region of BrTSR53 gene was cloned into an expression vector, pYES-DEST52, and a new protein with molecular weight of 13 kDa was detected by western blot analysis. Also, stress tolerance tests showed that BrTSR53-ORF transgenic yeast exhibited increased resistance to the salt stresses compared with the control. In conclusion, the present data predicts that novel ORF in BrTSR53 can serve as an important genetic resource for abiotic stress resistance.
        23.
        2015.07 서비스 종료(열람 제한)
        The detrimental effect of high salinity on crop production is a serious problem. However, the number of genes with known functions relating to salinity tolerance is very limited in rice. To effectively address this limitation, selection of useful candidate genes and identification of major regulatory factors through global approaches are necessary. To this end, we used three data series of affymetrix array data produced with salt-treated samples from NCBI Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/) and identified 653 rice genes commonly differentially expressed under three salt-stress conditions. While evaluating the quality of selected candidate genes for salt-stress responses, Gene ontology enrichment analysis revealed that responses to salt and water stresses of biological process category are highly overrepresented in salt-stress conditions. In addition, the major salt stress-responsive metabolism process and regulatory gene modules are classified through MapMan analysis, and detailed elements for further studies are suggested. Based on this, we proposed a salt stress-responsive signaling pathway in rice. The functional analysis of the main signal transduction and transcription regulation factors identified in this pathway will shed light on a novel regulatory metabolism process that can be manipulated to develop crops with enhanced salinity tolerance.
        24.
        2014.07 서비스 종료(열람 제한)
        Rice is a staple food for over one-half of the world population, especially in Asian countries. Recently, the growth and yield of crop plants was affected by various abiotic stresses, such as salt, drought, and high temperature due to change of climate environment. To study molecular functions of Oryza sativa nuclear-targeted RING Finger Proteins (OsNRFPs) in response to abiotic stresses, we selected 44 OsNRFPs genes, whose subcelluar localizations are predicted to the nucluear, on the basis of expression patterns of a microarray dataset. A total of 44 OsNRFPs were grouped into two types such as RING-HC and RING-H2 via phylogeneitc analysis of their RING domains structures. Subsequently, we surveyed the expression patterns of 44 genes in response to salt stress via qRT-PCR in roots. We found 10 salt stress-induced OsNRFPs and then examined their subcellular localizations. These genes were clearly localized to the nucleus (OsNRFPHC-10), cytoplasm (OsNRFPHC-17 and OsNRFPH2-16) and microtuble (OsNRFPHC-23, OsNRFPH2-17 and OsNRFPH2-05), respectively. These results might provide a key clue for understanding moleuclar functions of the OsNRFP genes associated with salt stress-related signaling pathway
        25.
        2014.07 서비스 종료(열람 제한)
        Crops are exposed to various environmental stresses. These have been affecting the growth of crops, resulting in the severe loss of agronomic production in many countries. Therefore, development of new varieties of resistant crops is required to assure the desired productivity of crops in stress conditions. In this study, a putatively stress-related gene BrTSR53 was isolated from Brassica rapa. The BrTSR53 is 481 bp long and contains ORF region of 234 bp. The expression of BrTSR53 was determined by quantitative real-time PCR analysis. After 3 hr, the highest quantities of mRNA were revealed in cold and salt stress treatments. In drought stress treatments, there was the highest expression after 36 hr. Therefore, it was confirmed that the ORF in BrTSR53 should be a gene that confer increased resistance to B. rapa growing in different stress conditions. The ORF region of BrTSR53 gene was cloned into an expression vector, pYES-DEST52, and a new protein with molecular weight of 13 kDa was detected by western blot analysis. Also, stress tolerance tests showed that BrTSR53-ORF transgenic yeast exhibited increased resistance to the salt stresses compared with the control. In conclusion, the present data predicts that novel ORF in BrTSR53 can serve as an important genetic resource for abiotic stress resistance.
        26.
        2014.07 서비스 종료(열람 제한)
        The purpose of this study was to establish a system for plant fluorescence image acquisition and to verify the possibility of plant fluorescence image analysis as a non-destructive method to screen the salt tolerance of soybean (Glycine max). Two-weeks-old seedlings of soybean at the V1 growth stage were treated with 0, 50, and 100 mM of NaCl for salt stress and plant fluorescence images were taken by CCD camera (EOS-600D, Canon, Japan) equipped with band pass filter (XNiteBPB, LPD LLC, USA) at 0, 15, 30, 60, 120 and 240 second after blue light exposure at 1 day after treatment. Red color intensity was extracted using MatLab 8.1 (The MathWorks Inc., USA) for estimation of plant fluorescence intensity. Red color intensity of soybean image decreased 0 (F0-10) to 240 (F240-250) second after blue light exposure irrespective of NaCl concentration, while F0-10/F240-250 decreased with NaCl concentration, resulting in significant relationship with plant fluorescence (Fv/Fm) and salt stress intensity. Therefore, our results suggest that our plant fluorescence image acquisition and analysis methods can be a part of high-throughput screening system for salt tolerance of soybean varieties
        27.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 제설제 피해에 따른 토양개량제 사용에 대한 가로변 하층식재로 이용될 수 있는 작살나무로 식물생육과 토양개량효과를 평가하고자 Control, T-W, T-SS, T-SC, T-TC를 실험구로 조성하여 식물생육과 토양화학성 변화를 분석하였다. 토양의 pH에서는 제설제 처리 후 수치가 다소 높아지는 경향이었으며 전기전도도의 경우 제설제 처리 후 증가한 후, 관수 및 토양개량제 처리 후 감소하여 초기값에 근접하는 경향이었다. 또한 치환성양이온 함량의 경우 칼슘이온(Ca2+)과 나트륨이온(Na+)에서 관수 및 토양개량제 처리한 실험구에서 유의한 수준으로 감소하여 그 효과를 검증할 수 있었으며 실험구별로는 T-SS, T-TC 실험구에서 양호한 수준이었다. 식물생육반응에서는 초기 활착시 개엽 상태가 얼마 지나지 않아 제설제를 처리하여 식물의 잎마름과 황엽현상이 빠르게 진행되었고, 잎의 낙화를 초래하였다. 하지만 토양개량제 처리 후 새순이 나타났으며, 지속적인 수세회복을 보였다. 엽록소 함량에서도 염화칼슘 처리 후 모든 실험구에서 감소하다가, 관수 및 토양개량제 처리 후 엽록소함량이 유의한 수준으로 상승하는 것을 확인할 수 있었다. 본 연구는 도시공원 및 가로수변 지피식물로 이용되면서 내염성이 강하다고 보고된 작살나무를 공시식물로 선정하여 제설제로 이용되고 있는 염화칼슘이 생육 및 토양이화학성에 미치는 영향을 알아보고자 한 것이다. 그러나 본 연구에서는 지피식물 중 작살나무 1종에 대해 실험구별 식재한 10주만의 결과를 제시하여 그 경향만을 확인한 것으로 향후 실제 제설제에 의해 피해를 받는 현장조사 및 측정을 통해 그 유의성을 추가적으로 검증해야 할 것이다. 본 연구의 결과는 최근 도로변 레인가든의 조성 등으로 인해 제설제의 가로변 집적이 우려되는 상황에 염화칼슘 저감 및 식물생육 활성화를 위한 기초자료 제공을 목적으로 한 것이므로 모든 식물과 대상지에 일반화 할 수는 없는 상태이므로 향후 다양한 식물과 토양처리기법 등에 대한 구체적 효과 검증이 뒷받침되어야 할 것이다.
        28.
        2013.07 서비스 종료(열람 제한)
        We investigated whether sound could alter gene expression in plants. Using a sound-treated subtractive library, a set of sound-responsive genes in plants was demonstrated through mRNA expression analyses. Of them, the rbcS and ald genes, which are light responsive, up-regulated their expression with sound treatment in both light and in dark conditions. This suggested that sound could be used as a gene regulator instead of light. When we analyzed ald gene expression using various single wavelengths, a significant increase in mRNA levels was found at 125 or 250 Hz but decreased at 50 Hz, indicating that the gene responded to sound in a wavelength-specific manner. To determine whether the ald promoter respond to sound, we generated transgenic rice plants harboring the chimeric gene consisting of a 1,506-bp promoter fragment of the ald gene fused to Escherichia coli GUS reporter gene. Analyses of mRNA expressison level of three independent transgenic lines sound-treated with 50 or 250 Hz for 4 h showed that the Gus gene expression in all three transgenic lines was up regulated by 250 Hz, but down regulated by 50 Hz. These results correlated with sound responsive mRNA expression pattern observed for the ald gene in rice plants, indicating that the 1,506-bp ald promoter confers sound-responsiveness on a reporter gene in transgenic rice plants. We also investigated whether sound waves could improve salt tolerance in rice seedling. The rice seedlings were sound treated with 800 Hz for 1hr, and then treated with 0, 75, 150, and 225mM NaCl for 3 days to observe changes in physiological and morphological aspects. Sound treatment seedlings resulted in enhanced salt stress tolerance, mainly demonstrated by the sound treated seedlings exhibiting of increased root relative water contents (RWC), root length and weight, photochemical efficiency (ratio of variable to maximum fluorescence, Fv/Fm), and germination rate under salt stress condition. This demonstrates that a specific sound wave might be used, not only to alter gene expression in plant, but also to improve salt stress tolerance.
        29.
        2013.07 서비스 종료(열람 제한)
        Low temperature is a major factor restrict to growth and limiting productivity of rice crops. We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under chilling stress and identified 20 chilling inducible genes in previously study. Ten such genes encoding bHLH, metal transporter and, zinc finger protein with unknown functions showed a significant change in expression under various abiotic stresses. Among them, OsCHI1 (Os07g15460), OsCHI2 (Os02g43660), and OsCHI3 (Os01g61160), were selected for further study. They have structural features such as metal-binding signature sequences in their protein sequences, and OsCHI genes were expressed in root of rice seedling and induced in chilling and salt or drought. Expression of OsCHI1, OsCHI3 and OsCHI2 were targeted to membrane and ER when transiently expressed in tobacco cell, respectively. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing showed increased tolerance to salt and drought stress in the seed germination and root elongation than that of wild type. This comprehensive study provides insight into the biological function of OsCHIs, which may be useful in understanding how rice plants adapt to unfavorable environmental conditions.
        30.
        2013.07 서비스 종료(열람 제한)
        In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.
        31.
        2013.07 서비스 종료(열람 제한)
        To determine the expression levels of genes related to the salt stress response in rice, gene expression profiles were investigated through microarray analysis using the rice mutant line Till-II-877. There were no significant changes in physiological response under salt stress of the mutant increased less than that in the WT. The intensity of gene expression was analyzed and compared between the wild type and mutant lines using a microarray. Among the most significantly affected pathways, α-linolenic acid metabolism and linoleic acid metabolism (in lipid metabolism), fructose and mannose metabolism and glycolysis-gluconeogenesis (in carbohydrate metabolism), cysteine and methionine metabolism (in amino acid metabolism), and carbon fixation (in the energy metabolism of photosynthetic organisms) showed changes in gene expression levels under salt stress. These results further our understanding of the effects of salt stress in rice and may aid in the development of salt-tolerant rice cultivars.
        32.
        2013.07 서비스 종료(열람 제한)
        Drought and salinity are the major abiotic stresses which are being continued to hamper the ecosystem and agriculture of the affected region. Plant species have adaptations to enhance their ability to tolerate stresses through physiological adjustment. Therefore, substantial amount of research are ongoing to provide insights about those mechanisms which enlighten the stress tolerance in plant. In this study, several rice cultivars were collected from the different parts of the world and ion accumulation experiments were conducted to select the best stress tolerant cultivar in drought and salt stress environment. For stress treatment, five rice cultivars were subjected to salt (200 mM NaCl) and drought (200 mM Mannitol) for 72h. Later Na+, Ca++, K+ concentrations in shoot and root samples were examined at different time interval. In both drought and salt stress, rice cultivar C201 (collected for uzbekistan) showed the lowest levels of Na+ ion and Na+: K+ ratio compared to other cultivars. It was significant parallel observation with pokkali (known salt tolerant cultivar). In this preliminary study, it was observed the C201 had more stress tolerant in terms of ion accumulation; however detail physiological studies are required to strengthen the idea regarding the best stress tolerant physiotype.
        33.
        2012.07 서비스 종료(열람 제한)
        Transgenic cymbidium plants containing drought and salt stresses tolerance genes were produced by using a highly efficient Agrobacterium-mediated transformation system. The gene (AtSZF2) is salt and drought stresses tolerant gene and transferred into cymbidium plants. These transgenic cymbidium plants are investigated for gene introduction by PCR and analyzed by salt and drought stresses to check its gene expression. To investigate the gene expression of AtSZF2, leaves of transgenic cymbidium plants were soaked in salt solution (200 mM NaCl). Also, transgenic cymbidium plants were kept under no watering for 6 weeks to check the expression of drought stress tolerance. As a result, wild type plants showed more damage than transgenic plants under salt treatment. Further, transgenic cymbidium plants retained green color and healthy status, while wild type plants showed no tolerance after 6 weeks of no-watering treatment.
        34.
        2012.07 서비스 종료(열람 제한)
        MYB-like domain (MLD) gene is a transcription factor that plays a diverse role in plant development and in response to abiotic stresses. In this study, we isolated and developed CaMV35S::OsMLD rice lines and determined its expression pattern under abiotic stresses. It has Myb_CC_LHEQLE superfamily similar to most transcription factor genes but with a very unique binding domain of SHLQKYR in the C-terminal region. Overexpressing rice lines showed enhanced tolerance to salinity with elevated mRNA transcript. Additionally, mRNA transcripts were up-regulated by ABA, H2O2 and dehydration stresses. Further investigation in the enhanced tolerance to salinity showed an increased accumulation of proline and a decreased in malondialdehyde contents indicating that OsMLD gene may be involved in the regulation of proline and osmolytes during abiotic stresses. These results showed that OsMLD gene could be used in the development of rice intended for soil with salinity-related problem.
        35.
        2012.07 서비스 종료(열람 제한)
        In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.
        36.
        2012.07 서비스 종료(열람 제한)
        Development of transgenic plant with desirable traits to cultivated plant is one of the important procedures in plant molecular breeding. However, applicable assessment of transgenic plant in laboratorial scale is not much except cultivating transgenic plant for a whole life in field condition. Here, we analyzed chlorophyll fluorescence in three transgenic soybean lines with AtMYB44 transcription factor for assessment of photosynthetic activity under abiotic stresses such as drought. Soybean varieties used in this study were ‘Bert’ and ‘Bert’ derived three transgenic soybeans, ‘AtMYB44 CM35101’, ‘AtMYB44 CM2471’, and ‘AtMYB44 CM4481’. Analyzed five different chlorophyll fluorescence variables are maximum PSII quantum yield (QY_max), steady state PSII quantum yield (QY_Lss), steady state non-photochemical quenching (NPQ_Lss), coefficient of photochemical quenching in steady-state (Qp_Lss), and fluorescence declineratio in steady-state (Rfd_Lss). To determine main chlorophyll fluorescence variable affected by abiotic stress, principal component analysis (PCA) was conducted with five chlorophyll fluorescence variables measured from four varieties. QY_Lss and NPQ_Lss were main chlorophyll fluorescence variables to evaluate abiotic stress, particularly in drought stress. In comparison with transgenic soybean lines based on chlorophyll fluorescence variables, ‘AtMYB44 CM2471’ and ‘AtMYB44 CM4481’ are more tolerant to drought than the others. Interestingly, three transgenic soybean lines which have a same AtMYB44 gene with different regions of chromosome revealed the quite different responses of chlorophyll fluorescence to drought treatment.
        37.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        MYB-like domain (MLD) gene is a transcription factor that plays a diverse role in plant development and in response to abiotic stresses. In this study, we isolated and developed CaMV35S::OsMLD rice lines and determined its expression pattern under abiotic stresses. The MLD has Myb_CC_LHEQLE superfamily similar to most transcription factor genes but with a very unique binding domain of SHLQKYR in the C-terminal region. Overexpressing rice lines showed enhanced tolerance to salinity with elevated mRNA transcript. Additionally, mRNA transcripts were up-regulated by ABA, H2O2 and dehydration stresses. Further investigation in the enhanced tolerance to salinity showed an increased accumulation of proline and a decreased in malondialdehyde contents indicating that OsMLD gene may be involved in the regulation of proline and osmolytes during abiotic stresses. These results showed that OsMLD gene could be used in the development of rice intended for soil with salinity-related problem.
        38.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        Physiological responses to salinity stress were evaluated in six rice genotypes differing in their tolerance to salinity at the seedling stage. Susceptible genotypes ('Dongjingbyeo', 'Hwayeongbyeo', and 'IR29') showed salt injury symptoms (mean 8.8) and higher visual score under salt stress than that of tolerant ones ('Pokkali', 'IR74009', and 'IR73571'). As salinity affects growth and physiological parameters, the six genotypes thus showed significant reduction because of salt stress. Tolerant Japonica/Indica bred lines ('IR74009', 'IR73571') showed lower reduction, 33.9%, 34.5%, and 50%, respectively, in plant seedling height, dry shoot weight and dry root weight than those of the susceptible Japonica varieties ('Dongjingbyeo', 'Hwayeongbyeo'), and the highest reduction under salt stress was observed in dry root weight, followed by dry shoot weight and seedling height, respectively. Shoot Na+ concentration of IR74099 and IR73571 was lower than that of the susceptible varieties, 'Dongjinbyeo' and 'Hwayeongbyeo'. There were no significant differences among genotypes in root Na+ concentration. Shoot K+ concentration showed a reverse tendency compared to shoot Na+ concentration. IR74009 and IR73571 had considerably lower ratio compared to 'Dongjinbyeo' and 'Hwayeongbyeo' in Na+/K+ ratio of their shoot and was not different the tolerant check, 'Pokkali'.
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