• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.399-403
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• 2003

In order to understand the protection effects of antioxidant enzymes against oxidative stress caused by various environmental stresses, transgenic tobacco (Nicotiana tabacum cv, Xanthi) plants expressing both copper/zinc superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts (referred to as CA plants) were subjected to highlight (1,100$\mu$mol m$^{-2}$ sec$^{-1}$) and chilling at 4$^{\circ}C$. The protection effects of CA plants using leaf discs were compared with those of transgenic plants expressing either CuZnSOD or APX in chloroplasts (SOD plants or APX plants, respectively) and non-transgenic (NT) plants. CA plants showed about 15％ protection in the photosynthetic efficiency (Fv/Fm) of photosystem II relative to NT plants 1 hr after treatment of both highlight and chilling, whereas they showed about 23％ protection in the redox state of P700 in photosystem I at 3 hr after treatment. SOD plants or APX plants showed an intermediate protection effect between CA plants and NT plants. These results demonstrated that the coexpression of CuZnSOD and APX in chloroplasts importantly involves in the protection effects against oxidative stress caused by various environmental stresses.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.2
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• pp.109-116
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• 2007

Environmental stress is the major limiting factor in plant productivity. As an effort to solve the global food and environmental problems using the plant biotechnology, we have developed transgenic tall fescue (Festuca arundinacea Schreb.) plants via Agrobacterium-mediated gene transfer method. To develop transgenic tall fescue plants with enhanced tolerance to the environmental stresses, both CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) genes were incorporated in a pIG121 binary vector and the both of the genes were controlled separately by an oxidative stress-inducible sweet potato peroxidase 2 (SWPA2) premoter expressed in chloroplasts. Leaf discs of transgenic plants showed 10-30% less damage compared to the wild-type when they exposed to a wide range of environmental stresses including methyl viologen (MV), $H_2O_2$ and heavy metals. In addition, when $200{\mu}M$ MV was sprayed onto the whole plants, transgenic plants showed a significant reduction of visible damage compared to wild-type plants that were almost damaged. These results suggest that over expression of CuZnSOD and APX genes in transgenic plants might be a useful strategy to protect the crops against a wide range of environmental stresses.

• Korean Journal of Plant Taxonomy
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• v.34 no.4
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• pp.335-358
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• 2004

To investigate molecular phylogenetic relationships and to test hypothesis of hybrid origin of Ranunculus cantoniensis (Ranunculaceae), the sequences of nrDNA and chloroplast DNA were analyzed for 8 taxa and 25 accessions including 5 accessions of outgroup. In the phylogenetic trees by analyses of maximum parsimony and maximum likelihood for ITS nrDNA sequences and combined data of psbA-trnH, rps16 and trnL sequences of cpDNA, R. cantoniensis was most closely related to R. chinensis, and then to R. taciroi and R. silerifolius. The molecular phylogenetic relationships were not congruent with the previous report that R. cantoniensis was most closely related to R. silerifolius. In the sequence analysis of ITS and psbA-trnH, rps16, trnL for R. cantoniensis and the related taxa, R. cantoniensis showed polymorphism. It supported that the polymorphism also was reported in chromosome number and karyotype of R. cantoniensis. Ranunculus cantoniensis shared the marker gene of R. chinensis and R. silerifolius in ITS, and one of R. silerifolius in cpDNA. These results supported the hypothesis that R. cantoniensis was caused by hybridization between R. chinensis and R. silerifolius based on chromosome number and karyotype, and also estimated that R. silerifolius might be of maternal origin and R. chinensis be paternal.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.200-207
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• 2019

The aim of this study was to provide the basic information necessary to identify Korean fir (Abies holophylla), momi fir (A. firma), and Nikko fir (A. homolepis), and other fir trees planted in South Korea that are protected by law. Analysis of the morphological characteristics of the needles from each sample was investigated. The shape of the needle-leaf tip from A. holophylla was acute, whereas that from A. firma and A. homolepis was emarginate and that from the protected fir trees was obtuse. The number of stomata on the needles was not significantly different between A. holophylla and A. firma, and the number of stomata on the needles from A. homolepis and the protected fir trees were highly similar. In addition, the genetic differences among the Abies species were analyzed using the sequences of five chloroplast DNA regions-matK, atpF-atpH, rpoC2-rps2, rpoC1, and psbA-trnH.The atpF-atpH and psbA-trnH regions were useful for discriminating A. firma from the other species, but there were no differences among A. holophylla, A. homolepis, and the protected fir trees. The same chloroplast sequences were found in both A. holophylla and A. homolepis, which suggests that additional genetic studies might be necessary to identify the Abies species planted in both South Korea and Japan.

• Journal of Life Science
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• v.32 no.12
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• pp.956-961
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• 2022

Plant Chloroplast have several advantages as an expression platform of biopharmaceuticals over conventional expression platforms such as mammalian cells, yeast and bacteria. First, plants do not serve as a host for mammalian infectious virus and have endotoxin like bacteria which can cause anaphylactic shock. In addition, high copy number of chloroplast genome allows for chloroplast transformants to reach the high level of expression of heterologous genes. Moreover, the integration of transgenes into specific region of chloroplast genomes makes chloroplast transformants unaffected by positional effect which can be frequently observed from nuclear transformants, resulting in loss of transgene expressions. Antimicrobial peptides (AMPs) are a kind of innate immunity which is found from bacteria to humans. Unlike conventional antibiotics, very less dosage of AMPs can have catastrophic effect on bacterial survival. Further, the repeated use of AMPs does not trigger the development of bacterial resistance. Moricin, one of the AMPs, was isolated from Bombyx mori, a silkworm moth. The C-terminal of moricin consists largely of basic amino acids, and the N-terminal has an α-helix structure. Moricin was chosen and expressed in a SUMO/SUMOase without leaving any unwanted amino acids which could potentially affect the anti-bacterial activity of the moricin. The transformation vector used in this study has already been created in this lab for the expression in both prokaryotic systems such as E. coli and chloroplast. The expressed moricin was purified using Ni columns and SUMOase, and the antibacterial activity of the purified moricin was confirmed using an agar diffusion assay.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.199-202
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• 2000

The leaf color varies with the contents of pigments, especially chlorophylls and carotenoids. Teichung 65 (T.65), a japonica rice, with pgl(pale-green leaf) gene exhibits pale green color on the whole plant from seedling to harvest. This study conducted to evaluate the agronomic characters and examine the chloroplasts of 'pgl' plants in parents and BC$_1$F$_2$ of T.65(pgl) xSuweon ${345}^2$. The average grain yield of pale-green-leaf individuals in F$_2$ was the same as T.65(pgl) but that of green-leaf individuals was much higher than that of Suweon 345. The contents of chlorophyll a(Ca), chlorophyll b(Cb) and total chlorophyll content(Ct) of T.65(pgl) in flag leaf were lower than those of Suweon 345, but the Ca/Cb ratio of T.65(pgl) was higher than that of Suweon 345 during from 15 days after heading (DAH) to 60 DAH. The SPAD value of T.65(pgl) in flag leaf was lower than that of Suweon 345, but that in the second and the third leaves was similar to that of Suweon 345. The SPAD value of pale-green-leaf individual group was lower than that of green individual group in upper three leaves. The structural difference of chloroplasts in flag leaf between T.65(pgl) and Suweon 345 through TEM at 20 DAH was not detected, but the number of osmium granules in chloroplast of T.65(pgl) were higher than that of Suweon 345.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.290-298
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• 2023

Several members of the genus Broussonetia are woody plants with high-quality cellulose fibers and are used to make a traditional type of Korean paper known as Hanji. Three of these species, Broussonetia kazinoki, Broussonetia monoica, and Broussonetia papyrifera, are found in the Korean Peninsula. Because it is challenging to distinguish different Broussonetia species based on morphology alone, we have developed a set of insertion/deletion (InDel) markers for genetic identification of these species. From twenty-two Broussonetia samples collected throughout Korea, we selected six for next-generation sequencing analysis. InDel marker candidates were identified by comparing this sequence information with the B. kazinoki chloroplast genome sequence. The marker candidates were used to screen the genomes of the twenty-two Broussonetia plants, and five useful chloroplast-based InDel markers were identified. Detailed genotyping using these five markers showed that the twenty-two plants of the genus Broussonetia could be clustered into five groups, verifying that the markers developed here can be used for breeding, identification, and analysis of species in the genus Broussonetia.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.1
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• pp.37-47
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• 1988

Endonuclease inhibitor was isolated from the chloroplast of the leaves of tobacco, Burley 21 and NC 83, The inhibitory effect on the activities of endonucleases including BamH1 was lost by the addition of trypsin or heat treatment However, the treatment of $\alpha$-amylase was unconcerned in the inhibitory effect The endonuclease inhibitor was found to be a monomeric protein that plays a vital role for protection of tobacco chloroplast DNA from endonuclease action.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.95-95
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• 2005

• Journal of Plant Biology
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• v.25 no.4
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• pp.181-188
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• 1982

Chloroplasts isolated from tobacco (Nicotiana tabacum L. cv. Virginia 115) leaves have been transferred into protoplasts of soybean (Glycine max Merr. cv. Jangyeop) suspension-cultured cells with the help of polyethylene glycol (PEG). The increased yield in protoplasts of chloroplast uptake was depended upon the concentration of both PEG 4,000 and PEG 6,000. The highest yield(36%) occurred at 50% of both PEG, and the yield was decreased above this concentration. The rate of uptake with the incubation time was highest at one hour, then decreased. The process of the chloroplast uptake into the protoplasts was similar with that of a protoplast fusion, except forming invagination during uptake.