• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.239-243
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• 2008

This experiment was carried out to elucidate the appropriate split application method of nitrogen fertilizer in infant rice seedlings which show poor seedling growth resulted from extended seedling nursery duration more than 12 days. The 16 day-old infant rice seedling (DOIRS) showed poor seedling growth than 8 day-old seedling. Early growth of transplanted 16 DOIRS was poor, compared with that of transplanted 8 DOIRS. However, the poor plant growth estimated by plant height, tiller number, and the number of newly developed roots was compensated by 70-0-30% (basaltillering-panicle initiation) of nitrogen split application. In 70-0-30% plots among split nitrogen application methods, tiller number, biomass, and leaf area at heading stage of rice showed the highest values. Sixteen DOIRS plots showed lower grain filling and 1000-grain weight, resulted in lower yield of rice than 8 DOIRS plots in the same nitrogen split application. However the lower yield in 16 DOIRS plots was recovered by 70-0-30% of nitrogen split application method to a similar level in 8 DOIRS plots in which nitrogen was split applied by 40-30-30%.

• Journal of Life Science
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• v.26 no.1
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• pp.59-67
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• 2016

Platycodon grandiflorum A. De Candolle (Korean name, ‘Doraji’) is a perennial plant containing various triterpenoid saponins. The roots of this plant have traditionally been used as a food material in Korea. Here, we prepared a fermented P. grandiflorum extract (PG). Although it was previously reported that P. grandiflorum A. extract has a variety of physiological functionalities, including anti-inflammatory and anti-oxidant activities, little is known about its vascular functions. In this study, we executed a series of experiments to identify the effect of PG on endothelial cells. PG at a high concentration (100 μg/ml) was found to induce cell detachment, whereas PG at a low concentration (0.1 μg/ml) appeared to promote cell proliferation and migration in bovine aortic endothelial cells. The cell detachment induced by the high concentration was not associated with cell death, such as apoptosis, necrosis, and autophagy. In addition, we found that PG at the high concentration formed a small vesicular structure called an endothelial microparticle (EMP). The EMP was prepared by centrifugal fractionation and determined with flow cytometry and a microscope. Interestingly, PG-induced cell detachment was found to be mediated by EMP. We furthermore determined that PG at the low concentration activated Akt, a crucial cell-signaling molecule, and then controlled cell proliferation and migration. Overall, our findings suggest that PG at low doses maintains vascular stability by promoting endothelial cell proliferation, and enhances the efficacy of wound healing by cell proliferation and migration activity.

• KSBB Journal
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• v.17 no.6
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• pp.525-530
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• 2002

The optimum culture conditions for tropane alkaloid production in hairy root cultures of Korea native Scopolia paviflora Nak. were investigated. Hairy root was induced from the rhizome of the mother plant on B5 medium containing 1.0 mg/L IBA. Among the culture media examined, 1/2 B5 medium was the best for tropane alkaloid production, whereas the growth of hairy root increased in SH medium. The best result on the growth of hairy root was obtained in 1.0 mg/L NAA, and tropane alkaloid production was obtained in plant growth regulator-free medium. Of the carbone sources tested, 3% sucrose promoted the growth of hairy root, whereas 5% sucrose increased tropane alkaloid production. Optimum inoculum densities for root growth and tropane alkaloid production were 0.5 g and 1 g, respectively. The addition of XAD resins (1 % w/v) to hairy root cultures led to increases in tropans alkaloid production, and the release of alkaloid into the medium and its adsorption by the resin accounted for about 50 to 80％ of total production. It is concluded that optimized culture conditions and the addition of XAD resins could be used in the development of a bioprocess for tropane alkaloid production in hairy root cultures of S. paviflora Nak.

• Journal of Radiation Protection and Research
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• v.36 no.4
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• pp.209-215
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• 2011

In order to investigate the soil-to-plant transfer factor (TF) of $^{99}Tc$ for Korean major upland crops (soybean, radish and Chinese cabbage), pot experiments were performed in a greenhouse. Soils were collected from four upland fields (two for soybean and two for radish and Chinese cabbage) around Gyeongju radioactive-waste disposal site. Three to four weeks before sowing, dried soils were mixed with a $^{99}Tc$ solution and the mixtures were put into pots and irrigated. TF values were expressed as the ratios of the $^{99}Tc$ concentrations in plants (Bq $kg^{-1}$-dry or fresh) to those in soils (Bq $kg^{-1}$-dry). There was no great difference in the TF value between soils. The TF values for soybean seeds were extremely lower than those for the straws, indicating a very low mobility of $^{99}Tc$ to seeds. As representative TF values of $^{99}Tc$, $1.8{\times}10^{-1}$, $1.2{\times}10^1$, $3.2{\times}10^2$ and $1.3{\times}10^2$ (for dry plants), arithmetic means for two soils, were proposed for soybean seeds, radish roots, radish leaves and Chinese cabbage leaves, respectively. In the case of the vegetables, proposals for fresh plants were also made. The proposed values are not sufficiently representative so successive updates are needed.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.183-189
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• 1986

Fifty three diseased root samples of Chinese cabbage and 22 soil samples were taken from six alpine areas in Kangwon province to examine the organisms causing root rot of Chinese cabbage. Among thirteen microorganisms detected from diseased roots samples, Pythium ultimum, Pythium echinocarpum and Rhizoctonia solani were detected frequently and were pathogenic to Chinese cabbage. Five to 100% of young Chinese cabbage plants grown in the sample soils taken from alpine cabbage fields were infected either alone or together with P. ultimum, P. echinocarpum and R. solani, depending upon the or gin of sample soils. When relative density of the three organsims in the sample soils was estimated based on the infection frequency on the plants grown in those sample soils, P. ultimum was prevalent only in Chahang-i-li area. P. echinocarpum was prevalent in Yongsan-il-li, Hoengwe-li, and Munmaek areas. R. solani was solely found in Maebongsan area where both P. ultimum and P. echinocarpum were not detected. In the three areas where both P. ultimum and P. echinocarpum were present, density of P. echinocarpum was generally greater than that of P. ultimum. Seedlings of thirty major Chinese cabbage varieties were inoculated independently with the three organisms in the greenhouse. Six varieties were resistant to P. ultimum. Three and two varieties were moderately resistant to P. ultimum and P. echinocarpum, respectively. All varieties were highly susceptible to R. solani.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.94-101
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• 2004

Commercial value of soybean sprouts should be affected by their morphology including the lateral roots. This study was carried out to determine the effect of benzyladenopurine (BA) concentration on growth and morphology of soybean sprouts in order to compare them with the selling products collected from the markets. Four cultivars (cv. Eunhakong, Pungsannamulkong, Sowonkong, and Junjery) were cultured for 6 days after imbibed for 5 hours into different BA solutions (0, 1,2,4, and 8 ppm). On the 6th day, hypocotyl length was measured to calculate the composition rate of ＞ 7 cm (A), 4 to 7 cm (B), ＜ 4 cm (C) and non-germination (D), and the ratio of hypocotyl to root length (H/R ratio) on the base of hypocotyl length as well as lateral root, hypocotyl diameter, and fraction fresh and dry weights. The composition rates classified with hypocotyl length showed big differences between 4 cultivars in class A and C; Class A, in which cv. Sowonkong and Junjery had higher rates than cv. Eunhakong and Pungsannamulkong, was decreased with BA concentration of higher than 4 ppm, but class C showed the reverse result to class A. Any lateral root was not formed in higher than 4 ppm BA solutions although fewer in cv. Pungsannamulkong and Junjery than in the two other cultivars. Hypocotyl and root lengths were decreased with increased BA concentrations, and in all BA concentration, hypocotyl length of cv. Junjery was the longest. Hypocotyl diameter, hypocotyl and total fresh weights were thicker and heavier in 2 to 4 ppm BA concentrations than in the other ones, although in case of BA application, cv, Eunhakong and Sowonkong were heavier. The H/R ratios were increased with increased BA concentration. The ratios of nearly all the selling products ranged from 1 to 2 ppm when compared to them from our experiment.

• Journal of Ginseng Research
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• v.38 no.4
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• pp.270-277
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• 2014

Background: The effect of methyl jasmonate (MJ) on ginsenoside production in different organs of ginseng (Panax ginseng Meyer) was evaluated after the whole plant was dipped in an MJ-containing solution. MJ can induce the production of antioxidant defense genes and secondary metabolites in plants. In ginseng, MJ treatment in adventitious root resulted in the increase of dammarenediol synthase expression but a decrease of cycloartenol synthase expression, thereby enhancing ginsenoside biosynthesis. Although a previous study focused on the application of MJ to affect ginsenoside production in adventitious roots, we conducted our research on entire plants by evaluating the effect of exogenous MJ on ginsenoside production with the aim of obtaining new approaches to study ginsenoside biosynthesis response to MJ in vivo. Methods: Different parts of MJ-treated ginseng plants were analyzed for ginsenoside contents (fine root, root body, epidermis, rhizome, stem, and leaf) by high-performance liquid chromatography. Results: The total ginsenoside content of the ginseng root significantly increased after 2 d of MJ treatment compared with the control not subjected to MJ. Our results revealed that MJ treatment enhances ginsenoside production not in the epidermis but in the stele of the ginseng root, implying transportation of ginsenosides from the root vasculature to the epidermis. Application of MJ enhanced protopanaxadiol (PPD)-type ginsenosides, whereas chilling treatment induced protopanaxatriol (PPT)-type ginsenosides. Conclusion: These findings indicate that the production of PPD-type and PPT-type ginsenosides is differently affected by abiotic and biotic stresses in the ginseng plant, and they might play different defense mechanism roles.

• Journal of Plant Biology
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• v.39 no.1
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• pp.71-77
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• 1996

Embryogenic callus was selected from callus induced from hypocotyl segment cultures of Daucus carota seedlings on MS basal medium supplemented with 1.0 mg/L 2,4-D. Cell clumps prepared from the embryogenic callus were transferred to MS medium without 2,4-D for somatic embryo development. Cotyledonary abnormalities were frequently observed on somatic embryos developed after the incubation of cell clumps in MS basal medium with 1.0 mg/L 2,4-D for one week and then subculture in the same medium but without 2.4-D for two weeks. The percentage of abnormalities was as follows: 5% one cotyledon, 21% three cotyledons, 6% four cotyledons, 5% five cotyledons, 0.2% six cotyledons and 1% trumpet-like cotyledons. On the other hand, the normal somatic embryo with two cotyledons appeared at 63%. The germination rate of somatic embryos was higher in two cotyledon somatic embryos than in multicotyledonary embryos. Trumpet-like somatic embryos did not germinate normally showing limited elongation and enlargement of roots and cotyledons without shoot development. From anatomical examination circular procambium in the root of somatic embryo began to branch around the middle regions of the hypocotyl which extended into the cotyledons through the cotyledonary nodes and the number of branched procambial strands in hypocotyl was equal to the number of cotyledons. Monocotyledonous somatic embryo always had larger cotyledon than that of somatic embryos with multicotyledons and had horseshoe-like cotyledons where the procambium was of the same structure.ucture.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.111-116
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• 2005

The two different ways to supply air inside the bioreactor were examined in the adventitious root cultures of Panax ginseng C.A. Meyer. First, the aeration rate varied at 0.05, 0.1, 0.2 and 0.3 vvm, respectively which were supplied during the whole culture period. Second, the amount of air supply was increased from 0.05 to 0.3 vvm at 10-day intervals in proportion to the root growth. Both the root growth and the ginsenoside accumulation were maximized to 175.8 g dry wt. of root growth and 4.3 mg/g dry wt. of ginsenoside accumulation when the aeration rate was increased gradually. The effect of the sparger pore size (15, 30 and $60\;{\mu}m$) in the bioreactor was also investigated, which suggested the greatest root growth (175.9 g dry wt.) in the $15{\mu}m$-sized sparger and the highest ginsenoside content (4.3 mg/g dry wt.) in the $60\;{\mu}m$ size. Finally, the diameter of a sparger ($15\;{\mu}m$-sized) varied at 1.5, 3.0, 5.0 and 8.0 cm, respectively. The highest root growth (191.9 g dry wt.) and the ginsenoside content (4.9 mg/g dry wt.) were obtained in the sparger diameter of 8.0 cm.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.311-319
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• 2011

Overusing chemical fertilizers involves potassium accumulation in the soil, which can become a toxicity problem in agriculture. This study was conducted to investigate the effect of potassium (K) treatment on growth, physiological characteristics, and morphological changes using Chinese cabbage (Brassica rapa L. ssp. campestris). With high (600 mM) K treatment, the plant growth traits of leaf length, leaf area, and fresh and dry weight of shoots and roots decreased, whereas chlorophyll content increased. As the concentration of K increasing, total N, P, and K increased in leaves, but concentrations of Ca, Mg, and Na decreased. However, Mn, Fe and Zn contents were highest in 100 mM K treatment. Chlorophyll a, b, and carotenoids increased with increasing K concentration. Maximum photochemical efficiency ($F_v/F_m$) was not significant in the all treatments, whereas $CO_2$ assimilation decreased with increasing K level due to stomatal degradation. Total free amino acids increased with the 10 and 100 mM K but decreased at 600 mM K treatments. Therefore, the growth and physiological characteristics of Chinese cabbage ascertained that tolerance up to 100 mM K when grown with nutrient solution in pot culture.