• Molecules and Cells
• /
• v.41 no.5
• /
• pp.413-422
• /
• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Analytical Science and Technology
• /
• v.17 no.2
• /
• pp.163-172
• /
• 2004

The molecular size distribution and fluorescence properties of soil fulvic acids (FA) were characterized by using gel filtration chromatography (GFC) and luminescence spectroscopy. The objectives of this work were to fractionate the FA extracted from a forest soil into different nominal molecular size using GFC system and to characterize the fluorescence properties (excitation, emission and synchronous) of these fractions using luminescence spectrometer. The GFC column was calibrated with polyethylene glycols, acetone and dextrane Blue. The total permeation volume of the GFC system was 404 mL and the void volume 130 mL. The GFC molecular weight of the soil FA was in the range of 190~8,900 Dalton and the molecular weight at the peak on the chromatogram was 930 Dalton. The fluorescence intensity ratio ($I_{498nm}/I_{390nm}$) was found to be increased with an increasing molecular weight. This results may suggest that the fulvic acid fractions with high molecular weight have large amount of the condensed aromatic compound.

• Korean Journal of Plant Resources
• /
• v.31 no.1
• /
• pp.37-51
• /
• 2018

Molecular phylogenetic analysis was conducted to evaluate the taxonomic relationships of genus Arisaema L. distributed in Korea and the molecular phylogenetic characteristics of three authentic Arisaema species for the herbal medicine Arisaematis Rhizoma (the rhizomes of A. amurense, A. heterophyllum, and A. erubescens). The sequences of three DNA barcodes (rDNA-ITS, matK, and rbcL) were analyzed using 50 samples of nine taxa consisted of eight Korean and one Chinese Arisaema with one outgroup (Dracunculus vulgaris). Both individual and combined phylogenetic analyses of three DNA barcode sequences revealed that the treated nine taxa are independently classified into six distinct clades (Clade I, A. amurense f. amurense and A. amurense f. serratum; Clade II, A. serratum and A. takesimense; Clade III, A. ringens; Clade IV, A. erubescens; Clade V, A. heterophyllum; Clade VI, A. thunbergii subsp. thunbergii and A. thunbergii subsp. geomundoense). These six clades were reasonably divided into three individual sections, Pedatisecta, Sinarisaema, and Tortuosa. Futhermore, the results of comparative DNA barcode sequences analyses provided a significant information for the taxonomic reconsideration of Arisaema L. at the specific and intraspecific level. However, we could not confirm the taxonomic characteristics or identity among the three authentic medicinal species through the molecular phylogenetic analyses of genus Arisaema L. for Arisaematis Rhizoma.

• Journal of Ginseng Research
• /
• v.45 no.2
• /
• pp.344-353
• /
• 2021

Background: Korean Red ginseng extract (KRGE) has beneficial effects on the cardiovascular system by improving endothelial cell function. However, its pharmacological effect on endothelial cell senescence has not been clearly elucidated. Therefore, we examined the effect and molecular mechanism of KRGE on the senescence of human umbilical vein endothelial cells (HUVECs). Methods: HUVECs were grown in normal or KRGE-supplemented medium. Furthermore, they were transfected with heme oxygenase-1 (HO-1) gene or treated with its inhibitor, a NF-κB inhibitor, and a miR-155-5p mimic or inhibitor. Senescence-associated characteristics of endothelial cells were determined by biochemical and immunohistochemical analyses. Results: Treatment of HUVECs with KRGE resulted in delayed onset and progression of senescence-associated characteristics, such as increased lysosomal acidic β-galactosidase and decreased telomerase activity, angiogenic dysfunction, and abnormal cell morphology. KRGE preserved the levels of anti-senescent factors, such as eNOS-derived NO, MnSOD, and cyclins D and A: however, it decreased the levels of senescence-promoting factors, such as ROS, activated NF-κB, endothelial cell inflammation, and p21 expression. The beneficial effects of KRGE were due to the induction of HO-1 and the inhibition of NF-κB-dependent biogenesis of miR-155-5p that led to the downregulation of eNOS. Moreover, treatment with inhibitors of HO-1, NF-κB, and miR-155-5p abolished the anti-senescence effects of KRGE. Conclusion: KRGE delayed or prevented HUVEC senescence through a signaling cascade involving the induction of HO-1, the inhibition of NF-κB-dependent miR-155-5p biogenesis, and the maintenance of the eNOS/NO axis activity, suggesting that it may protect against vascular diseases associated with endothelial senescence.

• Membrane Journal
• /
• v.33 no.6
• /
• pp.447-453
• /
• 2023

The performance of computer systems and the development of various computer simulation programs have made it possible to analyze chemical systems composed of more complex elements, and accordingly, research using molecular dynamics simulation is being actively conducted. Research on calculating the gas permeation characteristics of polymer membranes by molecular dynamics, which was previously conducted mainly through experiments, is receiving attention for gas barrier membranes used in food packaging and pharmaceuticals. Recently, there has been a report that a gas barrier effect appears when a coating film is made using silk fibroin, and in this study, a study was conducted using molecular dynamics simulation to confirm whether an oxygen barrier effect appears when a composite film is made using silk fibroin. We built a single model, calculated the gas permeation characteristics, and compared it with the experimental value to confirm that the model reflects the actual experimental results. Actual composite membrane models were then built and the gas movement path within the polymer was analyzed. As a result, oxygen molecules were found that they could not pass through and was blocked in the fibroin region. Therefore, the composite membrane with silk fibroin has excellent oxygen barrier property and is expected to be useful in food packaging, etc.

• Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.125-135
• /
• 2012

This study was carried out to understand the correlation between phylogenetic relationships based on 18S rDNA sequences and growth by salinity of Chlorella-like species. The 18S rDNA sequences of 71 Chlorella-like species which were mainly collected from Korean waters were analyzed. The 18S rDNA sequences of Chlorella-like species were divided into three groups (group A, B and C) and group B was further divided into three subgroups (subgroup B-1, B-2 and B-3). Thirty-seven Chlorella-like species in group A grew well at high salinity (32 psu) but the other groups grew well in freshwater. The sequence identities of the species in group A and B were 97.2-99.5%, but those of 6 species in group C ("Chlorella" saccharophila), which contained group I intron sequences region were 75.0-75.4%. Two representative species of each group were cultured at different salinities (0, 16 and 32 psu) to examine the correlation between the molecular phylogenetic groups and the phenotypic characteristics on cell growth and size by different salinities. The size of cell cultured at different salinities varied according to the species of each molecular phylogenetic group. The size of "Chlorella" saccharophila in group C was bigger and more obviously elliptical rather than that of the other Chlorella-like species. Considering the results on molecular and phenotypic characteristics, the group A and B belonged to Chlorellaceae, but group C was distinctly different from them.

• Korean Journal of Plant Taxonomy
• /
• v.42 no.1
• /
• pp.13-23
• /
• 2012

The trnL-F region islocated in the large single-copy region of the chloroplast genome. It consists of the trnL gene, the trnL intron, and the trnL-F IGS. Molecular evolution and phylogenetic relationships in Korean Thalictrum L. were investigated using data from the cpDNA trnL-F region. Bayesian and parsimony analyses of the data set with the gap characteristics recovered well-resolved trees that are topologically similar, with clades supported by some indels evolution. Indel events of cpDNA trnL-F in Korean Thalictrum were interpreted as phylogenetically informative characteristics. Sect. Physocarpum (excluding T. osmorhizoides) was an early-diverging group with in the genus and the remaining section formed strongly supported clades. Korean Thalictrum has various evolutionary patterns, such as the spatial distribution of the nucleotide diversity and transversion-type base substitutions in the trnL-F region.

• Membrane Journal
• /
• v.13 no.4
• /
• pp.211-218
• /
• 2003

The removal characteristics of cadmium in micellar enhanced ultrafiltration (MEUF) were investigated by using an anionic biosurfactant, deoxycholic acid (DCA). The ultrafiltration experiments were performed in a batch-type stirred cell. The ultrafiltration membranes used were Millipore YM1, YM3, YM10, and YM30 which had a difference in molecular weight cut-off. The presence of cadmium ion in DCA solution tends to reduce the critical micell concentration considerably and increase the micell size. The molecular weight cut-off of ultrafiltration membrane had a minimal effect on cadmium removal whereas DCA/Cd ratio had a substantial influence. When DCA/Cd ratio was 3, the removal efficiency of cadmium was more than 99.6%. A relative flux, which is defined as ratio of the flux for a separation trial to that of deionized water run using the same piece of membrane, decreased in the order of YM3 > YM1 > YM10 > YM30.

• Biomedical Science Letters
• /
• v.26 no.3
• /
• pp.244-248
• /
• 2020

Skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA) can occur especially in community populations such as military training camps. We investigated antimicrobial resistance patterns and molecular epidemiological characteristics of MRSA isolated from nasal swabs in healthy army trainees. From January 2018 to March 2018, one MRSA strain was isolated from nasal swab and hand of healthy army trainees. mecA gene detection, SCCmec and mec complex typing were performed to analyze the antimicrobial resistance patterns and molecular epidemiological characteristics of MRSA isolates. As a result, SCCmec and mec complex type of MRSA isolate from military trainees was not-typeable (n=1). In conclusion, not-typeable subtype of MRSA isolate from military trainees need to be confirmed by continuous follow-up study to determine whether there is a different genotype or a new subtype of genotype present in the Republic of Korea.

• Nuclear Engineering and Technology
• /
• v.52 no.2
• /
• pp.337-343
• /
• 2020

Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110)_oxide || (111)_Fe (oriented oxide) also had similar characteristics as that of (100)_oxide || (111)_Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide.