• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.184-189
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• 2011

To optimize tissue culture conditions for genetic transformation of Zoysia matrella (L.) Merr., we investigated the effects of different plant growth regulators and medium supplements on plant regeneration using stolon explants excised from mature plant grown in a green house. Plant regeneration frequency was 33.3% when stolon tissues with a node were cultured on the regeneration medium supplemented with 0.5 mg/L 2,4-D and 1 mg/L of kinetin. Comparing the basal media tested, MS medium showed higher plant regeneration performance than N6 or SH medium. Addition of 5 mg/L $AgNO_3$ with 10 mg/L cysteine improved frequency of plant regeneration up to 40%. Among different carbon sources, 3% sucrose was found to show the best for regeneration frequency. This rapid and efficient plant regeneration system would be useful for using genetic transformation experiments of manilagrass without intervening callus-mediated regeneration.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.87-93
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• 2011

S-Adenosylmethionine decarboxylase (SAMDC; EC 4.1.4.50), a key enzyme for polyamines biosynthesis, was tightly regulated for homeostatic levels. Carnation SAMDC gene (CSDC9) has an small upstream open reading frame (uORF) of 54 amino acids in 5'-leader sequence. To explore the functional mechanism of uORFs in controlling translation, we used a GUS reporter gene driven with the 35S promoter and uORF region of SAMDC gene for making transgenic tobacco plants. In our experiment, there were a translational inhibition of its downstream GUS ORF by SAMDC uORF sequence or SAMDC uORF protein. Expecially, translational inhibition was most effective in point-mutated construct, in which the start codon was changed. Therefore, this results suggested the ribosomal stalling might be involved in this translational inhibitory process. The frame shift in amino acid sequence of SAMDC uORF with start codon and stop codon resulted in a moderate increasing in GUS activity, suggesting the native amino acid sequence was important for a function as a translational inhibitor. Also, we showed that the production of GUS protein was significantly inhibited in the presence of the small uORF using histochemical analysis of GUS expression in seedlings and tobacco flowers. Importantly, the small uORF sequence induced a real peptide of 5.7 kDa, which was provided the presence of SAMDC uORF peptide band using an in vitro transcription/translation system. The peptide product of uORF might interact with other components of translational machinery as well as polyamines, which was resulted from that polyamine treatment was inhibited GUS protein band in SDS-PAGE experiment.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.153-160
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• 1997

Cucumber mosaic virus (CMV) leads to a cause of poor crop productivity and quality. To solve this problem, we attempted to develop a virus-resistance tobacco plants by using viral coat protein (CP) gene. Transgenic tobacco plants expressing CMV CP gene were analysed by the resistance upon CMV infection. The virus-resistance was measured in $\textrm{T}_{1}$, generation by the inhibition of plant growth and the expression of the mosaic symptoms infected with CMV. The transgenic lines were divided into four groups: highly resistant, resistant, moderate and susceptible based on their growth and symptom severity. Out of 39 transgenic lines, 16 lines showed significant virus-resistance. And of resistant lines, 2 lines were designated highly resistant based on the facts that they achieved similar plant height to that of non-infected tobacco plants and showed lower disease symptom than that of other lines. The steady state level of CP RNA and coat protein level were measured by northern blot and immunoblot analysis. The CP RNA was highly accumulated in most resistant and moderate lines but barely detected in susceptible lines. The coat protein was detected in most lines regardless of their resistance to CMV. from this result, virus-resistance appeared to correlate more with CP RNA level than the level of coat protein. However, in two highly resistant lines, CP RNA level was unexpectedly low. This unexpected phenomenon need to be further investigated.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.300-304
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• 1997

Leaf dise explants of Solanum tuberosum cultivar. Desiree and Atlantic, were infected with a Agrobacterium MP90 strain containing chimeric gene construct, consisting of antibiotic and low temperature regulated gene (H28) for transformation. regenerated multiple shoots were selected on a medium containing kanamycin and carbenieillin after exposure to Agrobacterium. Both PCR analysis of NPT Ⅱ, H28 genes and northern blot analysis indicated that the genes coding for the enzyme were successfully integrated into the potato genome and could be expressed in potato plants.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.450-456
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• 2016

Rhizoctonia leaf blight (large patch) has become a serious problem in Korean lawn grass, which is extremely hard to treat and develops mostly from the roots of lawn grass to wither it away. Rhizoctonia leaf blight (large patch) is caused by Rhizoctonia solani AG2-2 (IV). To develop zoysia japonica with strong disease tolerance against this pathogenic bacterium, ${\beta}-1,3-glucanase$ was cloned from zoysia japonica, which is one of the PR-Proteins known to play a critical role in plant defense reaction. ${\beta}-1,3-glucanase$ is known to be generated within the cells when plant tissues have a hypersensitive reaction due to virus or bacterium infection and secreted outside the cells to play mainly the function of resistance against pathogenic bacteria in the space between the cells. This study utilized the commonly preserved part in the sequence of corn, wheat, barley, and rice which had been researched for their disease tolerance among the ${\beta}-1,3-glucanase$ monocotyledonous plants. Based on the part, degenerate PCR was performed to find out the sequence and full-length cDNA was cloned. E.coli over-expression was conducted in this study to mass purify target protein and implement in vitro activation measurement and antibacterial test. In addition, to interpret the functions of ZjGlu1 gene, each gene-incorporating plant transformation vectors were produced to make lawn grass transformant. Based on ZjGlu1 protein, antibacterial activity test was conducted on 9 strains. As a result, R. cerealis, F. culmorum, R.solani AG-1 (1B), and T. atroviride were found to have antibacterial activity. The gene-specific expression amount in each organ showed no huge difference in the organs based upon the transformant and against 18s gene expression amount.

• Journal of Plant Biology
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• v.36 no.4
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• pp.377-382
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• 1993

Rice (Oryza saliva L.) calli containing both embryogenic callus (EC) and non embryogenic callus (NEC) regions were initiated from the mature seed on MS medium supplemented with 2.0 mg/L 2,4-D, 0.5 mg/L kinetin. The calli were developed into two callus type which can be distinguished by visual examination depending on color and appearance. In order to illucidate the polypeptide composition between EC and NEC, the total protein extracted from two types of callus was analysed by electrophoresis. By one-dimesional anlaysis of SDS-PAGE and Isoelectric focusing, several protein bands showed quantitative and qualitative difference in each type of callus. The further analysis of the total protein with two-dimensional electrophoresis showed at least 20 EC specific protein and 10 NE specific protein. Also 3 specific protein spots showing micro heterogeneity of 90, 65, 50 kD were detected in EC, while a series of acidic heterologous protein spots were visualized in NEC.in NEC.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.409-411
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• 2009

Phytochelatins (PCs) are small-sized peptides synthesized by PC synthase (PCS) using glutathione (GSH) as a substrate, and they play an important role in the detoxification of toxic heavy metals in plants, fission yeast, and other living organisms. Recently, it has been suggested that PCS is also involved in degradation of some xenobiotics including monobromobimane. PCS cleaves the Gly residue from GSH-xenobiotics conjugates resulting in ${\gamma}$-Glu-Cys-xenobiotics, and this is to degraded further. Therefore, our research is focus on whether PCS is also involved in degradation of tolclofos-methyl, an important pesticide which has been used in ginseng cultivated areas. Heterologous expression of Arabidopsis PCS confers tolerance to tolclofos-methyl in yeast. Furthermore, PCS-deficient Cad1-3 Arabidopsis mutant showed high sensitivity to tolclofos-methyl compared with wild-type plants. These results imply that PCS is involved in degradation of tolclofos-methyl as other xenobiotics.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.77-81
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• 1999

Tobacco plants(Nicotiana tabacum cv. NC82) transformed with TMV CP cDNA were self-fertilized until 8th generation (R$_{8}$), and the transgenic plants from 6th to 8th generation were analized for their resistance to tobacco mosaic virus(TMV) and stability of the gene expression. The 6th generation of the plants(R$_{6}$) showed high resistance(81-91 %) to TMV at eight weeks after artificial inoculation with the virus. The transgenic cell line 601 was the most prominant in the expression of resistance. 98 % of the plants showed no symptom without any agronomic phynotepe variation when they were inoculated with the virus in a experimental field. However, 2% of the plants were revealed as delay type of symptom with mild mosaic on a few leaves. The viral resistance in greenhouse tests of the 7th generation (R$_{7}$) was 54-64%, and the number of delay type plants were increased than that of 6th generation plants. In the 8th generation, 81 % of the plants was complete resistant to the virus. The TMV CP cDNA of the transgenic plants of each generation was also confirmed by genomic PCR, and there was no systemic viral multiplication in the resistant plants. It suggests that the viral resistance and gene expression of the transgenic plants might be stable through the generations.ons.s.

• Journal of Plant Biology
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• v.34 no.4
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• pp.289-296
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• 1991

Cultures of hairy root induced from ginseng(Panax C.A. Meyer) transformed with Agrobacterium rhizogenes (strain A4, ATCC 15834) were established and morphologically two different hairy root strains (HB1, HB2) were obtained. To determine the optimum growth rate, the hairy root (HB2) was cultured in various liquid medium supplemented with or without plant growth hormone. The growth rate of hairy root cultured on MS medium was 1.3-3.1 times higher than those cultured on other media, and the optimum sucrose concentration and pH were 3-6%, 5.5-6.5, respectively. Also, the growth rate of hairy root was increased when 0.02 M ammonium nitrate, 1.2 mM potassium phosphate (monobasic) and 0.5 mg/l IBA were supplied to liquid medium. The saponin patterns and contents of hairy root (HB2) were determined by TLC and HPLC. The crude saponin contents were 4.67% and the total saponin contents were 1.0%, on dry weight basis.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.185-191
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• 2013

Over the past decades, carbon dioxide concentration of the atmosphere of the world has increased significantly, and thereby the greenhouse effect has become a social issue. To solve this problem, new renewable energy sources including solar, hydrogen, geothermal, wind and bio-energy are suggested as alternatives. Among these new energy sources, bio-energy crops are widely introduced and under rapid progress. For example, corn and oilseed rape plants are used for the production of bio-ethanol and bio-diesel, respectively. However, grain prices has increased severely because of the use of corn for bio-ethanol production. Therefore, non-edible switchgrass draws attention as an alternative source for bio-ethanol production in USA. This review describes the shortage of fossil energy and an importance of switchgrass as a bio-energy crop. Also, some characteristics of its major cultivars are introduced including growth habit, total output of biomass yields. Furthermore, biotechnological approaches have been conducted to improve the productivity of switchgrass using tissue culture and genetic transformation.