• Plant Biotechnology Reports
• /
• v.4 no.4
• /
• pp.261-267
• /
• 2010

We describe culture conditions for a high-efficiency in vitro regeneration system of Papaver nudicaule through somatic embryogenesis and secondary somatic embryogenesis. The embryogenic callus induction rate was highest when petiole explants were cultured on Murashige and Skoog (MS) medium containing 1.0 mg $1^{-1}$ ${\alpha}$-naphthaleneacetic acid (NAA) and 0.1 mg $1^{-1}$ 6-benzyladenine (BA) (36.7%). When transferred to plant growth regulator (PGR)-free medium, 430 somatic embryos formed asynchronously from 90 mg of embryogenic callus in each 100-ml flask. Early-stage somatic embryos were transferred to MS medium containing 1.0 mg $1^{-1}$ BA and 1.0 mg $1^{-1}$ NAA to germinate at high frequency (97.6%). One-third-strength MS medium with 1.0% sucrose and 1.0 mg $1^{-1}$ $GA_3$ had the highest frequency of plantlet conversion from somatic embryos (91.2%). Over 90% of regenerated plantlets were successfully acclimated in the greenhouse. Secondary somatic embryos were frequently induced directly when the excised hypocotyls of the primary somatic embryos were cultured on MS medium without PGRs. Sucrose concentration significantly affected the induction of secondary embryos. The highest induction rate (89.5) and number of secondary somatic embryos per explant (9.3) were obtained by 1% sucrose. Most secondary embryos (87.2-94.3%) developed into the cotyledonary stage on induction medium. All cotyledonary secondary embryos were converted into plantlets both in liquid and on semisolid 1/3-strength MS medium with 1.0% sucrose.

• KSBB Journal
• /
• v.10 no.3
• /
• pp.249-256
• /
• 1995

${\gamma}$-Glutamylcysteine production by the immobilized microbial system of recombinant Escherichia coli and yeast was investigated. ${\gamma}$-Glutamylcysteine was synthesized from L-glutamic acid and L-cysteine in the presence of ATP by the reaction catalyzed by ${\gamma}$-glutamylcysteine synthetase. An immobilized microbial cell system was developed for the efficient ${\gamma}$-glutamylcysteine production. Recombinant Escherichia coli and yeast were immobilized by alginate. Production of ${\gamma}$-glutamylcysteine was better with the recombinant Escherichia coli for both the synthesis of ${\gamma}$-glutamylcysteine and the ATP regeneration than the mixed system of recombinant Escherichia coli and yeast. The proper radio of recombinant Escherichia coli to yeast was experimentary observed to be 1:4 in the mixed system. Although the immobi1ized system had the slower reaction rate, its reaction stability was increased by 10%.

• Molecules and Cells
• /
• v.39 no.6
• /
• pp.484-494
• /
• 2016

Plant cells have a remarkable ability to induce pluripotent cell masses and regenerate whole plant organs under the appropriate culture conditions. Although the in vitro regeneration system is widely applied to manipulate agronomic traits, an understanding of the molecular mechanisms underlying callus formation is starting to emerge. Here, we performed genome-wide transcriptome profiling of wild-type leaves and leaf explant-derived calli for comparison and identified 10,405 differentially expressed genes (> two-fold change). In addition to the well-defined signaling pathways involved in callus formation, we uncovered additional biological processes that may contribute to robust cellular dedifferentiation. Particular emphasis is placed on molecular components involved in leaf development, circadian clock, stress and hormone signaling, carbohydrate metabolism, and chromatin organization. Genetic and pharmacological analyses further supported that homeostasis of clock activity and stress signaling is crucial for proper callus induction. In addition, gibberellic acid (GA) and brassinosteroid (BR) signaling also participates in intricate cellular reprogramming. Collectively, our findings indicate that multiple signaling pathways are intertwined to allow reversible transition of cellular differentiation and dedifferentiation.

• Journal of Plant Biotechnology
• /
• v.32 no.2
• /
• pp.117-121
• /
• 2005

Immature embryos of 3 cultivars (Du Me Chal, Mi Baek Chal, Heug Jeom Chal) and 5 genotypes (HW1, KL103, HW3, HW4, KW7) were cultured on medium containing MS salts, Eriksson's vitamins, 1 mg/L 2,4-dichlorophenoxyacetic acid, 25 mM proline, 100 mg/L casamino acid, 3 mM MES, 1.7 mg/L $AgNO_3$ and 20 g/L sucrose (SIM). Frequency of somatic embryo formation on explant of immature embryos showed in HW1 (45.20%), KL103 (5.75%), HW3 (37.20%), HW4 (30.10%), KW70 (55.20%), Mi Baek Chal (18.74%), Heug Jeom Chal (22.41%), Du Me Chal (36.72%) and Hi II type (<10%), respectively. Yellowish friable embryogenic callus (YFEC) such as type II callus of Hi II genotype only produced from the HW3 and Heug Jeom Chal, whereas other cultivars and genotypes were directly formed somatic embryos with late-embryonic stages or expanded yellowish compact somatic embryo with morphological abnormality. The yellowish friable embryogenic callus (YFEC) could be proliferated on the same medium, which were maintained embryogenic capacity for 6 months over. Upon transfer to first regeneration and second regeneration medium, somatic embryos converted to plantlets at a frequency of approximately 100%. However, the expanded somatic embryos with abnormal morphology were slowly proliferated when subcultured on the same medium, and some of them were degenerated or converted to plantlets at a frequency of approximately 25%. Accordingly, The Heug Jeom Chal and HW3 genotype will be further used for development of high frequency transformation system in domestic maize germplasm.

• The Korean Journal of Physiology and Pharmacology
• /
• v.19 no.2
• /
• pp.105-109
• /
• 2015

NgR1, a Nogo receptor, is involved in inhibition of neurite outgrowth and axonal regeneration and regulation of synaptic plasticity. P19 embryonal carcinoma cells were induced to differentiate into neuron-like cells using all trans-retinoic acid and the presence and/or function of cellular molecules, such as NgR1, NMDA receptors and STAT3, were examined. Neuronally differentiated P19 cells expressed the mRNA and protein of NgR1, which could stimulate the phosphorylation of STAT3 when activated by Nogo-P4 peptide, an active segment of Nogo-66. During the whole period of differentiation, mRNAs of all of the NMDA receptor subtypes tested (NR1, NR2A-2D) were consistently expressed, which meant that neuronally differentiated P19 cells maintained some characteristics of neurons, especially central nervous system neurons. Our results suggests that neuronally differentiated P19 cells expressing NgR1 may be an efficient and convenient in vitro model for studying the molecular mechanism of cellular events that involve NgR1 and its binding partners, and for screening compounds that activate or inhibit NgR1.

• Journal of Plant Biotechnology
• /
• v.34 no.4
• /
• pp.293-298
• /
• 2007

Robinia pseudoacacia var. umbraculifera, commonly called umbrella black locust were regenerated after co-cultivation of internode segments with Agrobacterium tumefaciens which included yeast cadmium factor 1 (YCF 1) gene. The tolerance to cadmium and lead for plants can be increased by the YCF1 gene expression. Moreover, the recent studies have shown that YCF1 gene transgenic plants increase the accumulation of cadmium and lead into plant vacuoles. The effect of plant growth regulator such as 2,4-dichlorophenoxyacetic acid (2,4-D), ${\alpha}$-naphthaleneacetic acid (NAA), 6-benzyladenine (BA), and thidiazuron (TDZ) were studied to evaluate the propagation of plants through internode explants. The efficient induction of multiple adventitious shoots and callus were observed on a medium supplemented with 0.1 mg/L TDZ + 0.2 mg/L BA. To induce shoot elongation and rooting, regenerated shoots were transferred into basal MS medium without any plant growth regulator. Successful Agrobacterium tumefaciens mediated transformation was obtained by 20 min vacuum-infiltration with $50{\mu}M$ acetosyringone on the optimal multiple shoot induction medium with 30 mg/L hygromycin and 300 mg/L cefotaxime. To confirm the integration and expression of transgene, Polymerase Chain Reaction (PCR) and Reverse Transcriptase PCR (RT-PCR) were performed with specific primers. The frequency of transformation was approximately 18.94%. This study can be used to genetic engineering of phytoremediator.

• Asian Journal of Turfgrass Science
• /
• v.8 no.3
• /
• pp.137-147
• /
• 1994

We have established a high-frequency plant regeneration system via organogenesis from mature seed of Korean lawngrass(Zoysia japonica Steud.). The effects of 2,4-dichiorophenoxy acetic acid (2,4-D), 6-furfuryl amino purine (kinetin), $\alpha$-naphthaiene acetic acid (NAA), N6-benzyl amino pu-rine (BAP), and casein hydrolysate (CR) on cailus induction and multiple shoot formation on ex-posure to light were evaluated. Callus produced on the Murashige and Skoog (MS) medium containing 2,4-D and kinetin had high organogenesis potency. A single addition of 1.0 mg $L-^1$ 2,4-D significantly induced callus. Also, 1.0 mg L-$^1$ 2,4-D, with the addition of 0.1 mg $L-^1$ kinetin highly enlianced callus induction. The trend of cailus induction was also found on mediurn containing 0.1 mg $L-^1$ BAP with 1.0 mg $L-^1$2,4-D, and 1 g $L-^1$ CR with the addition of 1.0 mg $L-^1$ 2,4-D. However, NAA was no effective on callus formation. The growth of root was significantly high in the presence of 0.1 mg $L-^1$ kinetin compared to other concentrations. Over 2 mg $L-^1$ kinetin highly lengthened roots. Fresh weight of plantlet was highest on medium containing 0.1 mg $L-^1$ 2,4-D. Also, on medium containing 0.1 mg $L-^1$ BAP, fresh weight of piantlet was highly enhanced. BAP was significantly effective on multiple shoot formation, particularly when 2.0 mg $L-^1$ was added with 0.1 mg $L-^1$ 2,4-D. Callus induction and multiple shoot formation were achieved on MS basal medium containing 1.0 g $L-^1$ CH.

• Journal of the Korean Society of Tobacco Science
• /
• v.33 no.1
• /
• pp.8-15
• /
• 2011

Genus Nicotiana has 76 species including N. tabacum. These plants are used not only as a material for cigarette manufacturing but also as ornamental plant, medicinal plant, poisonous substance plant, and bug repellent plant. N. tabacum is used as a main material for cigarette manufacturing with N. rustica. N. sylvestris and N. alata is used as ornamental plants because of their beautiful flowers and N. rustica is used for bug repellent or pesticide because of its high concentration of nicotine. N. glauca, a tree tobacco, is used for bio-fuel production. N. tabacum is used as a popular model plant system for degeneration, regeneration, and transformation. N. benthamiana is also used as a model system for foreign gene expression by agroinfiltration. The transformation ability of tobacco plant is a good target for molecular farming. Hepatitis B virus envelop protein, E. coli heat-labile enterotoxin, diabetes autoantigen, and cholera toxin B subunit were produced using tobacco plants. Secondary metabolites of tobacco include nicotine, anabasine, nornicotine, anatabine, cembranoid, solanesol, linoleic acid, rutin, lignin and sistosterol, and they are used for various medicine productions which cannot be produced by organic synthesis for their complicated structures. In conclusion, we have to understand the applicability of tobacco plant in detail and study to enlarge the usage of the plants.

• Polymer(Korea)
• /
• v.39 no.1
• /
• pp.40-45
• /
• 2015

Simple poor-cosolvent casting was used to surface treat biodegradable elastic poly(L-lactide-co-${\varepsilon}$-caprolactone) (PLCL; 50:50) copolymer films that presented lotus-leaf-like structures. We evaluated whether the lotus-leaflike-structured PLCL (L-PLCL) films could be used as a biomaterial for artificial vascular grafts. The surface morphology, hydrophobicity, and antithrombotic efficiency of the films were examined while immersed in platelet-rich plasma (PRP) using scanning electron microscopy (SEM) and a contact angle meter. The recovery and crystallinity of the films were measured using a tensile-strength testing machine and an X-ray diffractometer, respectively. The solvent containing acetic acid, as a poor co-solvent, and methylene chloride mixed in a 1:2 ratio produced an optimal PLCL film with a water contact angle of approximately $124^{\circ}$. Furthermore, the surface of the L-PLCL films immersed in PRP showed a lower rate of platelet adhesion (<10%) than that of the surface of an untreated PLCL film immersed in PRP.

• Korean Journal of Agricultural Science
• /
• v.45 no.1
• /
• pp.43-49
• /
• 2018

The species of forage crops used in this study were Italian ryegrass (cv. Kowenery), sorghum (cv. SX17), proso millet (cv. domestic) and Japanese millet (cv. Jeju). The plant height of the summer crops was the highest at the dough stage. The dry matter yield of Italian ryegrass was 902.7 kg per 10 a. The dry matter yield of the winter crop and sorghum was 11,985 kg when harvested at the dough stage rather than at the first and second harvests. The proso and Japanese millet also had higher yields for dry matter during the dough stage rather than during heading and regeneration. The acid detergent fiber (ADF) content of Sorghum was lower than that of the first and second harvest; however, the proso and Japanese millet had a higher ADF content at the dough stage. The neutral detergent fiber (NDF) content was higher at the dough stage than at the first and second harvest, and the crude protein content was also lower at the dough stage than at the first and second harvest. The crude protein production for the dry matter yield was about 84 kg in Sorghum when harvested at the dough stage. Proso millet showed no difference for the crude protein production at the heading and dough stage while the Japanese millet had a higher crude protein production. There were no differences in the total digestible nutrients (TDN) content for the three crops according to the harvesting time. Therefore, if Sorghum and Proso and Japanese millet are to be combined with Italian ryegrass, it is better to harvest them at the dough stage.