• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.75-80
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• 2009

In order to develop transgenic sweetpotato plants [Ipomoea batatas (L.) Lam. cv. Yulmi] with enhanced tolerance to oxidative stress, we constructed transformation vectors expressing 2-Cys peroxiredoxin (Prx) gene under the control of the stress-inducible SWPA2 or enhanced 35S promoter (named as SP or EP). Transgenic sweetpotato plants were attempted to generate from embryogenic calli using an Agrobacterium-mediated transformation system. Embryogenic calli gave rise to somatic embryos and then converted into plantlets on MS medium containing 100 mg/L kanamycin. Transgenic plants were regenerated in the same medium. Southern blot analysis confirmed that the Prx gene was inserted into the genome of the plants. To further study we selected the transgenic plant lines with enhanced tolerance against methyl viologen (MV). When sweetpotato leaf discs were subjected to methyl MV at $20{\mu}M$, transgenic plants showed about 40% higher tolerance than non-transgenic or empty vector-transformed plants.

• Journal of Life Science
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• v.20 no.9
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• pp.1314-1323
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• 2010

In this study, we constructed various kinds of binary vectors with the pPZP backbone for co-overexpression, tissue- or development-specific expression and stress-inducible expression, and validated them for ectopic expression of target genes. Using a modified CaMV 35S promoter, a binary vector was generated for co-overexpression of two different genes and was confirmed to be efficient for overexpressing two different target genes at the same time and place. Binary vectors containing At2S3, KNAT1 or LFY promoters were constructed for tissue-specific or development-specific gene expression, and the binary vectors were suited for embryo/young seedling stage-, shoot apical meristem- or leaf primordia-specific expressions. Furthermore, the binary vectors containing RD29A or AtNCED3 promoters were validated as suitable vectors for gene expression induced by abiotic stresses such as high salt, ABA, MV and low temperature. Taken together, the binary vectors constructed in this study would be very useful for analyzing the biological functions of target genes and molecular mechanisms through ectopic expression.

• Journal of Life Science
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• v.30 no.5
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• pp.443-451
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• 2020

Recently, thrombotic diseases have become rapidly more prevalent due to Westernized lifestyles and high-fat diets. In this study, the anti-thrombosis activities of the aerial parts of Sageretia thea were evaluated using ethanol extracts of the leaf (ST-L), branch (ST-B), and fruit (ST-F), and their anti-coagulation, platelet aggregation inhibition, and hemolytic toxicity were assessed. In comparison to the ST-F extract, the ST-B exhibited 6.7 times more polyphenol content, and the ST-L had 2.7 times more total flavonoid content. The ST-L and ST-B extracts showed stronger inhibitions of thrombin, prothrombin, and blood coagulation factors than aspirin, berry extracts, or commercial oriental herbs. Furthermore, ST-L and ST-B showed superior platelet aggregation-inhibitory activities than aspirin. The ST-F extract demonstrated only minor anti-thrombosis effects, and none of the extracts showed hemolysis against red blood cells up to 1 mg/ml. Phenolic acid and flavonoid analysis of the ST-L and ST-B extracts showed abundant rutin, isoquercitrin, and astragalin as the major active compounds. Further research on the anti-thrombotic activity of isoquercitrin, a rare flavonoid from quercetin, is necessary. This is the first report of isoquercitrin in Sageretia thea, and our results suggest that ST-L and ST-B extracts could therefore developed as anti-thrombosis agents.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.793-799
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• 2016

This study examined Platanus orientalis and Ulmus davidiana planted in downtown parks to identify the correlations among microclimatic factors such as temperature in the crown, air flow, and wind speed. For the field survey, measurements were taken at 1 hour intervals from 09:00 am to 06:00 pm in August. For the measurement of microclimatic factors, data on temperature, light intensity, air flow, and wind speed were collected using a quantum sensor (PAR Quantum Sensor SKP215), a precision thermometer (Pt1000-Sensor), and a combination anemometer (1467 G4 & HG4). The results of the analysis demonstrated that both Platanus orientalis and Ulmus davidiana, showed a greater cooling effect inside the crown as compared with the outside temperature. The cooling effect inside the crown was more evident with air flow and wind speed factors. With relation to wind, the inner temperature of the crown of Platanus orientalis decreased due to air flow while that of Ulmus davidiana decreased due to wind speed. With no wind, the average variation in temperature inside the crown was $-0.9^{\circ}C$ for Ulmus davidiana and $-0.958^{\circ}C$ for Platanus orientalis, indicating that Platanus orientalis was relatively more effective in lowering the temperature of the planting space than Ulmus davidiana. This study is significant because it shows that different tree species have different effects on the microclimate and that factors affecting the formation of the microclimate of trees may vary with species. Further studies on species other than broad leaf trees, such as evergreen trees and shrubs, are required in order to plan the distribution of landscaping trees that are effective in regulating the microclimate within urban green spaces.

• Korean journal of applied entomology
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• v.17 no.4 s.37
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• pp.193-199
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• 1978

Five parents and their 10 $F_1$ crosses of maize (Zea mays L.) were tested by means of diallel analysis for the inheritance of peroxidase activity following Puccinia sorghi rust infection. Peroxidase activity was measured at day zero and at 2 days and 8 days after inoculation. Peroxidase activity was increased significantly by P. sorghi infection in all 15 genotypes after 8 days, but not after 2 days. Highly significant differences in peroxidase activity were detected among the 15 genotypes. The highly genera] resistant inbred, CM105, and its hybrids showed exceptionally high peroxidase activity in both healthy and infected plants. However, another highly resistant inbred, Oh545, showed exceptionally low peroxidase activity. Significant general combining ability (GCA) and specific combining ability (SCA) means quares were detected for peroxidase activity independent of disease. GCA mean spuares, however, were consistently a major contiribution to the inheritance of peroxidase activity in the infected plants whereas SCA men square contributions were minor. Rust resistant maize plants controlling mongenic dominant $Rp_1^d$gene showed stronger peroxidase reroxidase responses than their susceptible counterparts in the gel electrophoresis and densiometric tracings. The increased peroxidase activity occurred in both major leaf peroxidases, $Px_3\;and\; Px_7$.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.05a
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• pp.17-17
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• 2010

Ethylene, known as a stress hormone regulate wide developmental processes including germination, root hair initiation, root and shoot primordial formation and elongation, leaf and flower senescence and abscission, fruit ripening. The acceleration of ethylene biosynthesis in plant associated with environmental and biological stresses. 1-Aminocycloprophane-1-carboxlyate deaminase(ACCD) is an enzyme that cleaves ACC into and ammonia, a precursor of the plant hormone ethylene. Plant growth-promoting rhizobacteria (PGPR) having ACCD can decrease endogenous ACC level of tissue, resulting in reduced production of ethylene in plants. ACC deaminse was a key enzyme for protect stressed plants from injurious effects of ethylene. ACCD gene was encoded from Pseudomonas flourescens, PGPR and was cloned in Escherichia coli. We expressed the recombinant ACCD(rACCD) containing 357 amino acids with molecular weight 39 kDa that revealed by SDS-PAGE and western blot. The rACCD was purified by Ni-NTA purification system. The active form of rACCD having enzyme activity converted ACC to a-ketobutyrate. The optimal pH for ACC deaminase activity was pH 8.5, but no activity below pH 7.0 and a less severe tapering activity at base condition resulting in loss of activity at over pH 11. The optimal temperature of the enzyme was $30^{\circ}$ and a slightly less severe tapering activity at 15 - 30$^{\circ}$, but no activity over $35^{\circ}$. P. flourescens ACC deaminase has a highly conserved residue that plays in allowing substrate accessibility to the active sites. The enzymatic properties of this rACCD will provide an important reference for analysis of newly isolated ACCD and identification of newly isolated PGPR containing ACCD.

• Korean Journal of Plant Taxonomy
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• v.43 no.4
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• pp.300-311
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• 2013

Subalpine species, Sorbus pohuashanensis in the Korean peninsula, which is assumed to be evolved from hybridization between S. commixta and an unknown species based on the flavonoids data. Morphometric analysis was conducted on the basis of 19 leaf and flower (or fruit) characters. A total of 721 samples in 13 populations of Sorbus pohuashanensis and S. commixta from Korea and additional specimens of S. commixta, S. pohuashanensis, and S. wilsoniana from Japan and China were examined to reveal the hybridization patterns and morphological differences. We found a preliminary evidence where Korean mountain rowan is more related to a Chinese inland taxon, S. wilsoniana, rather than Northeastern Chinese S. pohuashanensis in terms of flavonoids. The current morphological structure of the Korean mountaion rowan, however, which is more similar to S. commixta, was neither associated with that of S. wilsoniana nor that of S. pohuashanensis. This indicates that this morphological variation represents an intermediate of S. commixta and S. wilsoniana via a more ancient hybridization event in terms of qualitative characters, such as stipules, buds, and carpels. These morphometric differences together with other distinguishing characteristics suggest that the Korean mountain rowan should be considered as a conspecific species of S. commixta, although this demonstration of hybridization with the current phenetic species concept contradicts longstanding historical species concept.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.196-207
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• 2016

In monsoon climates, persistent shade is a troublesome weather condition with an impact on the growth and yield of corn (Zea mays L.). We imposed 7, 14, 21, and 28 days of consecutive shade (CS) on Gwangpyeongok and P3394 corn hybrids at the beginning of the kernel filling stages. Shade had little impact on leaf area and dry matter accumulation in the stem and leaves. However, dry matter accumulation in the ear was severely reduced by approximately 28% and 53% after 14 and 28 days of CS, respectively. For the components of grain yield, 7 and 14 days of shade did irreparable damage to the number of filled kernels, the kernel number per ear row, and the percent of filled kernels, but did little damage or reversible damage after removal of the shade to the 100-grain weight and the row number per ear. Shade significantly reduced the relative growth rate (RGR) due to a decrease in the net assimilation rate (NAR). These results suggest that source activity limitation by shade during the kernel filling stages leads to the inhibition of sink activity and size. The yield of biomass, ear, and grain logistically declined as the length of CS increased. Probit analysis revealed that the number of days of CS needed to cause 25% and 50% reductions in grain yield were 3.7 and 23.1, respectively. These results suggest that the plant yield loss induced by shade at the beginning of the kernel filling stages is mainly achieved within the first 7 days of consecutive shade.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.124-124
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• 2017

Cadmium (Cd) is of particular concern because of its widespread occurrence and high toxicity and may cause serious morpho-physiological and molecular abnormalities in in plants. The present study was performed to explore Cd-induced morpho-physiological alterations and their potentiality associated mechanisms in Sorghum bicolor leaves at the protein level. Ten-day-old sorghum seedlings were exposed to different concentrations (0, 100, and $150{\mu}M$) of $CdCl_2$, and different morpho-physiological responses were recorded. The effects of Cd exposure on protein expression patterns in S. bicolor were investigated using two-dimensional gel electrophoresis (2-DE) in samples derived from the leaves of both control and Cd-treated seedlings. The observed morphological changes revealed that the plants treated with Cd displayed dramatically altered shoot lengths, fresh weights, and relative water content. In addition, the concentration of Cd was markedly increased by treatment with Cd, and the amount of Cd taken up by the shoots was significantly and directly correlated with the applied level of Cd. Using the 2-DE method, a total of 33 differentially expressed protein spots were analyzed using MALDI-TOF/TOF MS. Of these, treatment with Cd resulted in significant increases in 15 proteins and decreases in 18 proteins. Significant changes were absorbed in the levels of proteins known to be involved in carbohydrate metabolism, transcriptional regulation, translation and stress responses. Proteomic results revealed that Cd stress had an inhibitory effect on carbon fixation, ATP production and the regulation of protein synthesis. In addition, the up-regulation of glutathione S-transferase and cytochrome P450 may play a significant role in Cd-related toxicity and stress responses. Our study provides insights into the integrated molecular mechanisms involved in response to Cd and the effects of Cd on the growth and physiological characteristics of sorghum seedlings. The upregulation of these stress-related genes may be candidates for further research and use in genetic manipulation of sorghum tolerance to Cd stress.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.119-125
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• 2002

Application of phytoremediation in the polluted area to remove undesirable materials is a complex and difficult subject without detailed investigation and experimentation. We investigated the accumulation patterns of cadmium and lead in plants naturally grown, the bioavailability of plants to accumulate these toxic metals and the responses of P. thunbergii to cadmium and lead. The soil samples contained detectable lead (<17.5$\mu\textrm{g}$/g), whereas cadmium was not detected in the soils of study area. The whole body of Persicaria thunbergii contained detectable lead (<320.8$\mu\textrm{g}$/g) but cadmium was detected only in the stem (<7.4$\mu\textrm{g}$/g) and root (<10.4$\mu\textrm{g}$/g) of P. thunbergii. Cadmium was not detected in Trapa japonica and Nymphoides peltata, whereas lead was detected in T. japonica (<323.7$\mu\textrm{g}$/g) and N. peltata (<177.5$\mu\textrm{g}$/g). Correlation coefficient between lead content in soil and in these plant samples represented positive correlation. The total content of lead in each plant sample increased in the order of N.peltata$\leq$P.thunbergii