• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.168-173
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• 2011

This study was carried out to optimize the embryogenic callus induction and plant regeneration from mature seeds of Sorghum bicolor. The effect of growth regulators was investigated on formation of embryogenic callus. The highest frequency of embryogenic callus was observed when the mature seeds were cultured on B5 medium supplemented with 2 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D). The highest frequency of plant regeneration from embryogenic callus was observed on MS medium with 0.5 $mg\;l^{-1}$ 6-benzyl amino purine (BAP) and 0.25 $mg\;l^{-1}$ indole-3-butyric acid (IBA) to optimize the shoot regeneration. High concentration of BAP (1 $mg\;l^{-1}$) supplemented with IBA (0.25 $mg\;l^{-1}$) was effective combination for shoot multiplication. MS medium supplemented with 1 $mg\;l^{-1}$ IBA was found to be the most effective for inducing roots. Normal rooted plantlets were transferred to the greenhouse for hardening with over 90% survival rate. Hence, this reproducible protocol could be useful for mass propagation and genetic transformation of S. bicolor.

• Journal of Ginseng Research
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• v.37 no.4
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• pp.451-456
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• 2013

Compound K is a major metabolite of ginsenoside Rb1, which has various pharmacological activities in vivo and in vitro. However, previous studies have focused on the pharmacokinetics of a single metabolite or the parent compound and have not described the pharmacokinetics of both compounds in humans. To investigate the pharmacokinetics of ginsenoside Rb1 and compound K, we performed an open-label, single-oral dose pharmacokinetic study using Korean Red Ginseng extract. We enrolled 10 healthy Korean male volunteers in this study. Serial blood samples were collected during 36 h after Korean Red Ginseng extract administration to determine plasma concentrations of ginsenoside Rb1 and compound K. The mean maximum plasma concentration of compound K was $8.35{\pm}3.19$ ng/mL, which was significantly higher than that of ginsenoside Rb1 ($3.94{\pm}1.97$ ng/mL). The half-life of compound K was 7 times shorter than that of ginsenoside Rb1. These results suggest that the pharmacokinetics, especially absorption, of compound K are not influenced by the pharmacokinetics of its parent compound, except the time to reach the maximum plasma concentration The delayed absorption of compound K support the evidence that the intestinal microflora play an important role in the transformation of ginsenoside Rb1 to compound K.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.49-55
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• 2017

We investigated the callus induction and plant regeneration ability of 16 maize genotypes, including the Korean inbred lines, using 9 to 15 day-old immature zygotic embryos from maize grown in pots and from field cultures. Immature zygotic embryos placed on MS medium supplemented with L-proline 0.7 g/L, MES 0.5 g/L, Dicamba 1.5 mg/L, 2,4-D 0.5 mg/L, $AgNO_3$ 4 mg/L, and sucrose 20 g/L, showed the highest frequency of callus induction. The highest number of shoots regenerated when the embryogenic callus were transferred to MS medium supplemented with 5 mg/L zeatin. The root formation was observed when shoots were grown on MS medium supplemented with 0.2 mg/L indole-3-butyric acid (IBA). Additionally, under the same culture conditions, immature zygotic embryos from maize grown in the field also had a high frequency of plant regeneration. Except one genotype, 15 genotypes showed callus induction and shoot regeneration. Among the 16 genotypes tested, H99, B98, HW3, and B73 yielded the best plant regeneration. H99 showed maximum shoot formation from the primary embryogenic callus. The results suggest that genotypes and growth conditions of the maize plant plays very important roles for enhancing the embryogenesis competence of immature zygotic embryos. The successful regeneration from immature zygotic embryos of maize inbred lines provides a basis for molecular breeding of new cultivars by genetic transformation.

• Food Science and Preservation
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• v.13 no.6
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• pp.769-773
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• 2006

This study was to investigate the biological activities of green tea seed methanol extract (GTSME) and compared those of green tea methanol extract (GTME) for using green tea seed as the functional food material. The hydrogen-donating activity of GTSME was over 50% at the $100 {\mu}g/mL$ concentration the activity of GTME was 21.86% at the $1000{\mu}g/mL$ concentration compared with that of control. The MDA (malondialdehyde) production was 60 Mol/g and 50 Mol/g in the mouse liver homogenate teated with GTME and GTSME of $1000{\mu}g/mL$ concentrations, respectively, and the values were lower than 86 Mol/g of control. GTME and GTSME of $1000{\mu}g/mL$ concentration inhibited the proliferation of over 50% and over 20% in A549 and SW480 human cancer cells, respectively. The morphology transformation was shown in the cancer cells treated with GTSME of $500{\mu}g/mL$ with the decrease of cell numbers lower than that of control cells numbers. The NO production was increased in a dose dependent manner in the RAW264.7 macrophage cells treated with GTME and GTSME of 1, 10, 100 and $1000{\mu}g/mL$ concentrations, and the NO production by GTSME was $2.04{\mu}M$ at $100{\mu}g/mL$ concentration, and the value was higher than $0.77{\mu}M$ by GTME.

• Journal of Microbiology
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• v.43 no.3
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• pp.251-256
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• 2005

In this study, we assessed the susceptibility of 12 Lactobacillus strains, all of which had been isolated from the gastrointestinal tracts of chicken, to three antibiotics (chloramphenicol, erythromycin and tetracycline) used commonly as selective markers in transformation studies of lactic acid bacteria. Among these strains, $17\%,\;58\%,\;and\;25\%$ were found to exhibit a high degree of resistance to $200\;{\mu}g/ml$ of tetracycline, erythromycin, and chloramphenicol, respectively. Seven of the 12 Lactobacillus strains exhibiting resistance to at least $50\;{\mu}g/ml$ of chloramphenicol or erythromycin, and five strains exhibiting resistance to at least $50\;{\mu}g/ml$ of tetracycline, were subsequently subjected to plasmid curing with chemical curing agents, such as novobiocin, acriflavin, SDS, and ethidium bromide. In no cases did the antibiotic resistance of these strains prove to be curable, with the exception of the erythromycin resistance exhibited by five Lactobacillus strains (L. acidophilus I16 and I26, L. fermentum I24 and C17, and L. brevis C10). Analysis of the plasmid profiles of these five cured derivatives revealed that all of the derivatives, except for L. acidophilus I16, possessed profiles similar to those of wild-type strains. The curing of L. acidophilus I16 was accompanied by the loss of 4.4 kb, 6.1 kb, and 11.5 kb plasmids.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.359-371
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• 2019

To optimize the expression and secretion of ferritin protein associated with ion storage in the mushroom, Pleurotus eryngii, a recombinant secretion vector, harboring the ferritin gene, was constructed using a pPEVPR1b vector under the control of the CaMV 35S promoter and signal sequence of pathogen related protein (PR1b). The ferritin gene was isolated from the T-Fer vector following digestion with EcoRI and HindIII. The gene was then introduced into the pPEVPR1b secretion vector, and it was then named pPEVPR1b-Fer. The recombinant vector was transferred into P. eryngii via Agrobacterium tumefaciens-mediated transformation. The transformants were selected on MCM medium supplemented with kanamycin and its expression was confirmed by SDS-PAGE and western blotting. Expression of ferritin protein was optimized by modifying the culture conditions such as incubation time and temperature in batch and 20 L airlift type fermenter. The optimal conditions for ferritin production were achieved at 25℃ and after incubating for 8 days on MCM medium. The amount of ferritin protein was 2.4 mg/g mycelia, as measured by a quantitative protein assay. However, the signal sequence of PR1b (32 amino acids) seems to be correctly processed by peptidase and ferritin protein may be targeted in the apoplast region of mycelia, and it might not be secreted in the culture medium. The iron binding activity was confirmed by Perls' staining in a 7.5% non-denaturing gel, indicating that the multimeric ferritin (composed of 24 subunits) was formed in P. eryngii mycelia. Mycelium powder containing ferritin was tested as a feed additive in broilers. The addition of ferritin powder stimulated the growth of young broilers and improved their feed efficiency and production index.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.83-90
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• 2006

To develop transgenic birdsfoot trefoil (Lotus corniculatus L.) plants tolerant to environmental stress, Arabidopsis NDPK gene (AtNDPK) was introduced into birdsfoot trefoil plants using Agrobacterium-mediated transformation and expressed powerfully under the control of the E35S promoter. The expression vector, pEN-K was used for introduction of AtNDPK gene into birdsfoot trefoil plaits. The transformed calli were selected on kanamycin containing medium and then regenerated. The transformed birdsfoot trefoil plants were cultivated for 4 months on BOi2Y medium. Genomic DNA PCR and Southern blot analysis confirmed the incorporation of AtNDPK into the birdsfoot trefoil genome.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.356-360
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• 2005

Mature embryos were aseptically excised with a scalpel and sliced in fragments measuring 0.5 mm in diameter (sliced mature embryo fragment; 4 ${\~}$ 5 fragments/one embryo). Sliced mature embryo fragments of six wheat cultivars were cultured to develop an efficient method of callus induction and plant regeneration. Callus derived from sliced mature embryo fragments showed a good capacity to embryogenesis and regeneration. Furthermore sliced mature embryo fragments decreased contamination from fungi and bacteria. The high efficiency of callus induction were obtained Keumkangmil and Bob­white. For plant regeneration, selected embryogenic calli were transferred to two types regeneration media. An average number of green spots per callus was 4 to 5 in regeneration media after about one week. Percentage of plant regeneration showed high in regeneration medium containing 0.1 mg/l 2,4-D and 5 mg/l zeatin. Especially, Keumkangmil ($27.5\%$) and Bobwhite ($33.3\%$) showed high regeneration efficiency. This regeneration system from sliced mature embryo fragments may provide an effective and convenient explant for plant transformation studies.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.129-134
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• 2005

Callus induction from a leaf explant has been achieved in Lilium Oriental hybrid 'Casa Blanca'. The highest frequency of callus induction was obtained on MS medium supplemented with 0.5 mg/L BA and 2.0 mg/L NAA after 2 months of culture. The cultures maintained continuously without change in color and type of callus when they cultured in the dark. Plantlet regeneration with a high frequency was achieved from induced calli on the same medium. A number of shoots are formed from one cluster of callus, and bulblets developed into intact plantlets after transfer to hormone-free MS medium. No phenotypic variations were observed among regenerants. Enhancement in plantlet regeneration via callus formation would be expected to facilitate the efficiency of transformation of this Oriental hybrid 'Casa Blanca'.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.235-239
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• 2004

We studied the effect of genotype, explant, age of explant, medium (plant growth regulators and gelling agents), and standardized an efficient regeneration protocol for inbred lines of Chinese cabbage (Brassica rapa ssp. pekinensis). Of the different concentrations of NAA and BA tested, the combination of $5\;\cal{mg/L}\;BA\;and\;0.5\;\cal{mg/L}$ NAA gave the highest frequency of shoot regeneration. The cotyledonary explants had more shoot regeneration frequency ($\ge40\%$) than the hypocotyl ex-plants. Besides, the cotyledonary explants, excised from the 4-day old seedlings, showed higher shoot regene-ration ($56.7\%$). Of the three gelling agents and their concentrations used, 16 g/L agar was found to be the best for shoot regeneration. Shoot regeneration frequency in-creased significantly by supplementing the medium with $4\;\cal{mg/L}\;of\;AgNO_3$ MS medium devoid of NAA showed higher frequency of rooting in the regenerated shoots than the ones supplemented with NAA. Our improved regeneration protocol will be especially useful for the genetic transformation of Chinese cabbage inbred lines to develop transgenic hybrids.