• Korean journal of applied entomology
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• v.23 no.3 s.60
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• pp.137-141
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• 1984

Crude sap, which was extracted from six Amaranthaceae plants, inhibited local lesion formation on Nicotiana glutinosa by tobacco mosaic virus(TMV) infection. Especially the remark. able inhibitory effect to TMV infection was shown on leaves of N. glutinosa precoated with the sap from Amaranthus mangostanus. The inhibitory activity of the sap from A. mangostanus was stable to storage in vitro for I day and to dilution 1/4 of the sap with distilled water. However, its activity was lost when the sap was heated at $70^{\circ}C\;to\;100^{\circ}C$ for 10 minutes. When the leaves of N. glutinosa precoated with the sap were sprayed with water, the inhibitory effect to TMV infection was maintained for 2 days. The A. mangostanus sap readjusted pH 3, pH 5, or pH 9 with 1 N HCl or 1 N NaOH did not decline the inhibitory action but the sap absorbed with $5\%\;to\;15\%$ charcoal completely lost their action. The protein components purified from A. mangostanus sap revealed three major bands by $5\%\;to\;15\%$ polyacrylamide gel electrophoresis and the top component of which showed the inhibitory action to TMV infection.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.449-460
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• 2012

Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the GST gene present in Panax ginseng genome as well as its expression and function. A GST cDNA (PgGST) was isolated from P. ginseng cDNA library, and it showed the amino acid sequence similarity with theta type of GSTs. PgGST in ginseng plant was induced by exposure to metals, plant hormone, heavy metals, and high light irradiance. To improve the resistance against environmental stresses, full-length cDNA of PgGST was introduced into Nicotiana tabacum. Overexpression of PgGST led to twofold increase in GST-specific activity compared to the non-transgenic plants, and the GST overexpressed plant showed resistance against herbicide phosphinothricin. The results suggested that the PgGST isolated from ginseng might have a role in the protection mechanism against toxic materials such as heavy metals and herbicides.

• Molecules and Cells
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• v.38 no.10
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• pp.866-875
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• 2015

COPI vesicles are essential to the retrograde transport of proteins in the early secretory pathway. The COPI coatomer complex consists of seven subunits, termed ${\alpha}-$, ${\beta}-$, ${\beta}^{\prime}-$, ${\gamma}-$, ${\delta}-$, ${\varepsilon}-$, and ${\zeta}$-COP, in yeast and mammals. Plant genomes have homologs of these subunits, but the essentiality of their cellular functions has hampered the functional characterization of the subunit genes in plants. Here we have employed virus-induced gene silencing (VIGS) and dexamethasone (DEX)-inducible RNAi of the COPI subunit genes to study the in vivo functions of the COPI coatomer complex in plants. The ${\beta}^{\prime}-$, ${\gamma}-$, and ${\delta}$-COP subunits localized to the Golgi as GFP-fusion proteins and interacted with each other in the Golgi. Silencing of ${\beta}^{\prime}-$, ${\gamma}-$, and ${\delta}$-COP by VIGS resulted in growth arrest and acute plant death in Nicotiana benthamiana, with the affected leaf cells exhibiting morphological markers of programmed cell death. Depletion of the COPI subunits resulted in disruption of the Golgi structure and accumulation of autolysosome-like structures in earlier stages of gene silencing. In tobacco BY-2 cells, DEX-inducible RNAi of ${\beta}^{\prime}$-COP caused aberrant cell plate formation during cytokinesis. Collectively, these results suggest that COPI vesicles are essential to plant growth and survival by maintaining the Golgi apparatus and modulating cell plate formation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.146-152
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• 1997

Development of shoot and root, leaf water potential and photosynthetic rate affected by water stress in early growing stage of tobacco were surveyed to interpret stress response in terms of plant physiological and agricultural aspects. The growth of shoot and root was highly suppressed by water stress and the difference in dry weight by rewatering was smaller in root than in shoot. The total root length was highly decreased by water stress and the lengths of root for water stress and non-stress were 74m and 84m, respectively, after rewatering. The root growth treated by water stress was increased between 2nd and 3rd day after treatment indicating that temporary water stress at early growing stage might have increased of root zone activity for early growth stage. The leaf water potentials were decreased to -7.63MPa, -9.47MPa, -11.89MPa, -13MPa at the 2nd, 3rd, 4th and 5th day by water stress. The relative water contents were 75%, 62% and 57% at the 3rd, 4th and 5th day after treatment. Photosynthesis was reduced largely by water stress. The photosynthetic rate after treatment at 2nd day and 3rd day was dropped to 18.15$\mu$mol. $CO_2$/$m^2$ㆍsec$^{-1}$ and 9.35$\mu$mol. $CO_2$/$m^2$ㆍsec$^{-1}$. It was never recovered to the normal, even after rewatering. Stomatal conductance had been reduced since 2nd day after treatment and increased after rewatering.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.143-149
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• 1986

Anatomical changes in the forming and germinating processes of tobacco seeds were investigated to obtain basic information on the ecological characteristics of tobacco seeds. Seed development studied through the longitudinal section of the fertilized ovule clarified that the cell division of the zygote was initiated after 7 days of flowering. After 12 days of flowering, perfect seed constituents such as cotyledon, epicotyle and radicle were formed and those were expressed to recognizable level of germinability. After 15 days of flowering germination rate reached higher than 30% and 17 and 21 days after flowering a perfect seed which have 70% or higher germinability were produced. Seed size was ranged between 0.3-0.6 mm and varietal differences were noted in the given seed size range. Under the light treatment, the morphological changes were observed by elongation of radicle after 2 days of imbibition and apparent germination after 3 days of imbibition. But no responses of the seeds imbibed 6 days under the dark condition were observed.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.256-262
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• 2003

To enhance the production of heavy chain immunoglobulin G (HC IgG) in the suspension cultures of transgenic tobacco cells (Nicotiana tabacum), the effects of adding various cytokinins (i.e., growth regulators) and organic nitrogen sources to culture media were investigated. Four different cytokinins including kinetin, isopentenyladenine (IPA), 6-benzylaminepurine (BA), and zeatin were tested with or without dichlorophenoxyacetic acid (2,4-D), which is a typical growth regulator supplemented in the standard Murashige and Skoog (MS) medium. The productivity of intracellular HC IgG was increased by 36 and $42\%$, compared to the control, especially when IPA (2 mg/l) or BA (0.2 mg/l) was added to the media in the presence of 2,4-D, respectively. In the study of organic nitrogen sources, addition of each casein hydrolysate and tryptone to the culture media at a final concentration of 0.01 and 1 g/l, respectively. increased the productivity or he IgG as much as 68 and $67\%$, respectively, in comparison with the control, which was is MS medium without supplementation of any organic nitrogen sources. This study shows that the optimization of media composition could offer significant improvements in the production of foreign proteins in the suspension cultures of transgenic plants.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.361-368
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• 2005

A Korean isolate of Pepper mild mottle virus (PMMoV-Kr) was isolated from a diseased hot pepper plant and its biological and molecular properties were compared to that of PMMoV-J and PMMo V -So The genomic RNA of PMMoV-Kr consists of 6,356 nucleotides. The nucleotide and amino acid sequences identities of four viral proteins and two noncoding regions among PMMoV-Kr, PMMoV-S and PMMoV-J were $96.9\%\;to\;100.0\%\;and\;97.5\%\;to\;98.6\%$, respectively. Full-length cDNA amplicon of PMMoV-Kr was directly amplified by RT-PCR with a set of 5'-end primer anchoring T7 RNA promoter sequence and 3'-end virus-specific primer. Capped transcript RNAs from the full-length cDNA clone were highly infectious and caused characteristic symptoms of wild type PMMoV when mechanically inoculated to systemic host plants such as Nicotiana benthamiana and pepper plants.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.433-437
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• 2015

The infectious full-length cDNA clones of Cucumber green mottle mosaic virus (CGMMV) isolates KW and KOM, which were isolated from watermelon and oriental melon, respectively, were constructed under the control of the cauliflower mosaic virus 35S promoter. We successfully inoculated Nicotiana benthamiana with the cloned CGMMV isolates KW and KOM by Agrobacterium-mediated infiltration. Virulence and symptomatic characteristics of the cloned CGMMV isolates KW and KOM were tested on several indicator plants. No obvious differences between two cloned isolates in disease development were observed on the tested indicator plants. We also determined full genome sequences of the cloned CGMMV isolates KW and KOM. Sequence comparison revealed that only four amino acids (at positions 228, 699, 1212, and 1238 of the replicase protein region) differ between the cloned isolates KW and KOM. A previous study reported that the isolate KOM could not infect Chenopodium amaranticolor, but the cloned KOM induced chlorotic spots on the inoculated leaves. When compared with the previously reported sequence of the original KOM isolate, the cloned KOM contained one amino acid mutation (Ala to Thr) at position 228 of the replicase protein, suggesting that this mutation might be responsible for induction of chlorotic spots on the inoculated leaves of C. amaranticolor.

• The Plant Pathology Journal
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• v.33 no.4
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• pp.382-392
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• 2017

This study reports the findings of a distinct Potato virus Y (PVY) isolate found in Northeast China. One hundred and ten samples (leaves and tubers) were collected from potato plants showing mosaic symptoms around the city of Harbin in Heilongjiang province of China. The collected tubers were planted and let to grow in a greenhouse. New potato plants generated from these tubers showed similar symptoms, except for one plant. Subsequent serological analyses revealed PVY as the causing agent of the disease. A novel PVY isolate (referred to as HLJ-C-44 in this study) was isolated from this sample showing unique mild mosaic and crisped leaf margin symptoms. The complete genome of this isolate was analyzed and determined. The results showed that HLJ-C-44 is a typical PVY isolate. Phylogenetic analysis indicated that this isolate belongs to the N-Wi strain group of PVY recombinants ($PVY^{N-Wi}$) and also shared the highest overall sequence identity (nucleotide and amino acid) with other members of this strain group. However, recombination analysis of isolate HLJ-C-44 revealed a recombination pattern that differed from that of other $PVY^{N-Wi}$ isolates. Moreover, biological assays in four different potato cultivars and in Nicotiana tabacum also revealed a different phenotypic response than that of a typical $PVY^{N-Wi}$ isolate. This data, combined, suggest that HLJ-C-44 is a novel PVY recombinant with distinct biological properties.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.103-107
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• 1998

Tobacco proembryos were irradiated with 100 Gy of heavy-ion beams($^{14}\textrm{N}$, $^{20}\textrm{Ne}$: 135 Mev/u) after 24 to 96 hours of pollination as a mutagen and screened $\textrm{M}_{1}$ generation for morphological mutants and salt-tolerant plants. Morphological and physiological characteristics of the salt-tolerant plants derived from the irradiated proembryo are discussed in this report. Mutants irradiated proembryos with the beams after pollination produced various kinds of morphological variation. A total of 17 salt-tolerant plants were selected from tobacco cultivar (BY-4) by treatment with $^{14}\textrm{N}$ beam. Shapes of filament and pollen grain of most salt-tolerant plants were abnormal compared with non-irradiated wild type, and seeds weight and fertility obviously decreased. The germination rates of the several $\textrm{M}_{2}$ lines on the saline and the mannitol condition were higher than that of wild type.