• Proceedings of the Botanical Society of Korea Conference
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• 1999.08a
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• pp.68-82
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• 1999

CHilling tolereance of plants are closely correlated with the degree of fatty acid unsaturation of membrane lipids. We studied the effects of low-temperature photoinhibition on the photochemical efficiency of photosystem II in terms of fatty acid unsaturation of thylakoid membranes lipids isolated from chilling -sensitive plants and chilling -resistant ones. To directly test the chilling tolerance of photosynthetic machinery in relation to membrane lipids, we further compared wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids after being transformed with cDNA for glycerol-3-phophate acyltransferase from squash. The functional integrity of photosystem II during and recovery of photosynthesis from low-temperature photoinhibition will be discussed in connection with the degree of fatty acid unsaturation of chlorophast membranes lipids.

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.73-82
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• 2002

The committing step in Met and S-adenosyl-L-methionine (SAM) synthesis is catalyzed by cystathionine ${\gamma}$ -synthase (CGS). Transgenic Arabidopsis thaliana overexpressing CGS under control of 35S promoter show increased soluble Met and its metabolite S-methylmethionine, but only at specific stages of development. CGS-overexpressing seedlings are resistant to ethionine. Similar results were obtained with transgenic potato plants overexpressing Arabidopsis CGS. Several of the transgenic lines show silencing of CGS resulting in deformed p]ants with a reduced capacity for reproductive growth similar as transgenic plants by antisense RNA (CGS[-]). Exogenous feeding of Met to the CGS[-] and CGS[+] silenced plants partially restores their growth. Similar morphological deformities are observed in plants cosuppressed for SAM synthetase, even though such plants accumulate 250 fold more soluble Met than wild type and they overexpress CGS. The results suggest that the abnormalities associated with CGS and SAM synthetase silencing are due in part to a reduced ability to produce SAM, and that SAM may be a regulator of CGS expression.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.524-530
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• 2009

We scrutinized the Korean taxonomic literature, with special focus on some nomenclatural points and four different cases were listed categorically. Several naked names (nomen nudum), invalidly published names, typographical and orthographical errors, incorrect use of hybrid names and authorship, and errors in the citation of the bibliographic references have appeared in newly published literature in Korea, due to misapplications of ICBN (International Code of Botanical Nomenclature). Although literature review and synonyms are imperative and essential elements of taxonomic study, many author citations tend to be copied from one publication to another without any confirmation of the original source. It is strongly recommended that scientists who have previously published careless work should be more careful, and they should be instructed to read original descriptions and to learn current practices in the code.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.19-49
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• 1987

Recent development of recombinant DNA techniques such as gene cloning and DNA sequencing has led to understanding of genetic information coded on plant genes and their application to crop improvements. Nuclear genes so far isolated and characterized at the molecular level from various plants are those involved mainly in photosynthesis, nitrogen fixation, seed development and defensive responses to environmental stresses. Most of plant genes contain intervening sequences (introns) flanked with GT and AG, as it typical of animal genes. The 5' flanking regions of plant gene revealed the presence of promoter elements such as TATAAA and CCAAT, which have been identified at animal genes to be involved in transcrip- tion initiation. The 3' untranslated regions include a sequence similar to AATAAA whcih functions as a polyadenylation signal in other eukaryotic genes. Furthermore, enhancer-type sequences were found at the 5' flanking regions of various plant genes. This indicates that the structure of plant genes is very similar to animal genes and mechanisms governing the synthesis and processing of mRNAs may be identical in higher eukaryotes. However, genes expression studies involving transformation revealed their differ ences within plants and between plant and animal systems.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.349-356
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• 1987

Insertions of transposable elements in or near a structural gene give rise to null phenotypes, reduced levels of gene expression, or alteration on the tissue-specific pattern of gene expression. Null phenotypes often result from insertions in exons. Reduced levels of gene expression results from insertions in various regions such as promoter region, 5' non-translated region, exon and intron. The maize allele of Adh1-3F1124 is an example of alteration in the tissue-specific patetern of gene expression. Adh1-3F1124 contains a Mu element inserted 31 bp 5' to the transcriptional start site of the wild-type Adh1 activity in seeds and anaerobically-treated seedlings but normal levels in the pollen. Upon the insertion of a transposable element a certain number of host DNA sequences at the insertion site is duplcated. When transposable elements excise, all element sequences are deleted. However, the duplicated host sequences may be left intact or deleted to various extents. This results in null phenotypes, restoration of original levels of gene expression, or altered levels of gene expression. On the basis of effects of transposable-element insertions or excisions on gene expression, the usefulness of transposable ellements for studies on gene expression is discussed.

• Plant Resources
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• v.7 no.3
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• pp.222-225
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• 2004

In Japan, propagation of cyclamen is mainly from seedlings. However, seeds are expensive and germination is slow and non..uniform. Therefore, to achieve genetically uniform propagation, multiplication must be vegetative. The rooted tuberous stems without shoots as sources of explants were cultured on the media containing BA and sucrose. After 30 days cultivation, tuberous roots were produced from the root ends attached to a tuberous stem and its capability was dependent on the type of media. The highest percentage of tuberous root formation was observed in Culture on the medium of 1/3 MS containing 0.05mgL$^{-1}$ NAA, 0.5mg L$^{-1}$ BA and 5% sucrose. Growth rates of the tuberous roots were greatly influenced by the cutting positions of a root in explants. The highest growth of was observed if small amount of root end was cut at initiation of tissue culture.

• Proceedings of the Botanical Society of Korea Conference
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• 1993.07a
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• pp.1-36
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• 1993

It is possible to regenerate plants from calli, single cells and protoplasts of numerous species via organogenasis or embryogenesis in cell and tissue culture systems. Also such regeneration of plants can directly occur from cells of explants. However certain plant species has not been yet provided cultures suitable for plant regeneration from cells or tissues. For example, we have to confirm the regenerability of plant from cells before preparing transformed cells for application. Even more, it is very important to notice that regenerated plants in cell and tissue cultures often show structural abnormality. The mojority of those plants is functionally disordered and eventually cases degenerated. One of such examples is vitreous plants which are manifested mainly in the leaves and manifesteds to a lesser extent in the stems and roots. Regenerants in suspension cultures show more frequent vitrification than on gelled media so that relative humidity and water potential are the key factors involved in abnormal morphogenesis in vitro. The other is that somatic embryos formed in media containing BAP or high concentration of sucrose show frequently cotyledon aberrancy such as polycotyledon and born type cotyledon. The embryos with aberrant cotyledon of Codonopsis lanceolata could not germinate or regenerate into plants in many cases. In contrast, the polycotyledon embryos of Aralia cordata germinated in higher percentage than two cotyledonary embryos, but horn type cotyledonary embryos rarely germinated. The major cause of poor germination is the abnormal development of plumule apex meristem.

• Journal of Pharmacopuncture
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• v.23 no.2
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• pp.71-78
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• 2020

Objectives: This study was conducted to development of hazardous materials management standards for the decoction type of personalized herbal medicines (PHMs). Methods: This study was conducted in two stages. We searched documents about criteria to use words such as 'Herb', 'Herbal medicine', and 'Botanical Drug' and summarized the results. We organized the committee consisted of seven experts, and held two meetings to reach an agreement on hazardous management standards of the decoction type of PHMs. Results: The seven documents were presented in the literature review and six items related to hazardous management standards of decoction were identified. The second expert meeting brought that a total of six items, including heavy metal, pesticide residues, sulfur dioxide, benzopyrene, mycotoxin, and micro-organism limits, were selected for safety management of decoction type of PHMs. Also, the criteria and test methods for each standard were suggested for monitoring the decoction type of PHMs. Conclusion: The study suggested hazardous material management standards and criteria for the decoction types of PHMs. In the future, it would be necessary to conduct a pilot test to ensure the validity and credibility of the safety management standard and criteria. Furthermore, the government level safety management system should be introduced to verify the safety of decoction medicines.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.1
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• pp.13-25
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• 2001

Recently there have been increasing demands and desire for the urban open space due to urban development or environmental deterioration. Urban natural parks in Seoul provide citizens with comfortable open space and thus play an important role as learning spaces to experience nature and understand the environment. Accordingly, this study aims to analyze existing vegetation and provide basic data for the conservation and management plans of urban natural parks and education programs. The contents of the study encompass natural environment such as topography, altitude, slope and aspect and botanical ecosystem including the structure of plant communities and tree growth. According to the result of topography analysis, the overall altitude was not high but the slope was relative steep. Vegetation of Seoo Royal Tomb, a urban natural park has been classified into 12 types, and they include; Quercus acutissima community(lowland type), Quercus acutissima community(valley type), quercus variabilis community, Quercus mongolica community, Castanea crenata community, Capinus laxiflora community, Pinus densiflora community(lowland type), Pinus densiflora community(slope type), Robinia pseudo-acacia community, Populos$\times$albaglandulosa community, Pinus rigida community, and Pinus koraiensis community. Based on the survey and analysis results, we have classified the study area into conservation, buffer, and utilization zones for the effective management. This study provides basic data to support the establishment of master plans for urban natural parks by analyzing vegetation conditions at Seoo Royal Tomb, an urban natural park, Based on the results presented in the study, consistent monitoring work needs to be conducted, and elaborate management plans also should be prepared.

• Korean Journal of Plant Taxonomy
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• v.43 no.2
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• pp.106-117
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• 2013

Using scanning electron microscope (SEM), we examined the trichomes on leaf and petiole and the epicuticular waxes on leaf surfaces for a total of 27 taxa representing two subtribes, Fragariinae and Potentillinae, of tribe Potentilleae (Rosaceae) in Korea. Four types of trichomes on adaxial and abaxial surface of leaves and petioles were identified. Type I (conical hirtellous) is the most common trichome type found in the majority of taxa in Fragariinae and Potentillinae. Type II (verruculose conical hirtellous) can be found only in Potentilla cryptotaeniae of sect. Conostylae of Potentillinae. Potentilla chinensis complex (sect. Conostylae) and P. egedii (sect. Letostylae) have type III trichome (crispate villous), while type IV (floccose villous) can be found in two species in sect. Conostylae, P. nivea and P. discolor. Both woolly hairs and conical hirtellous exist together in types III and IV. The same type of trichomes in leaves and petioles can be found across different subtribes and sections. In addition, different types of trichomes can be found even in a single species. Among the taxa which have type I trichome, the majority of subtribe Fragariinae and P. centrigrana and P. dickinsii complex have well developed epicuticular waxes on the surface of leaves. Sharing epicuticular waxes among the taxa across different subtribes appears to be correlated with their similar geographical distribution and ecological conditions. However, molecular phylogenetic study implies that the existence of epicuticular waxes could be also due to phylogenetic signal.