• BMB Reports
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• v.51 no.7
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• pp.317-318
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• 2018

Plants are unable to relocate themselves to a more favorable location and thus have to deal with developmental programs and environmental cues wherever they happen to be. It is yet largely unknown how plant cells coordinate cellular activities and architectures to accomplish developmental processes and respond to environmental changes. By identifying and establishing a new cellular model system, we have discovered that two neighboring cell types in the abscission zone (AZ) of Arabidopsis flowers coordinate their activities to ensure a precise "cut" through a highly restricted area of plant tissue to bring about organ separation. From this perspective, we further discuss the essence of cellular coordination in AZ, the key molecules controlling the organ separation, and relevant implications.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.6-9
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• 2005

Plant biotechnology involving genetic modification has been rather controversial. However, the major issues related to safety are being addressed by continued improvements in technology. Some of the related facts will be highlighted to set the tone for a scientific discussion on the possibilities of using the technology for crop improvement. Our main research interest is to understand the molecular regulation of shoot bud regeneration in plant tissue culture, which is essential for crop improvement by biotechnology. We have isolated and characterized some genes that are associated with adventitious shoot regeneration. These include a MADS-box cDNA (PkMADS1) from paulownia kawakamii, which regulates vegetative shoot development and in vitro shoot regeneration from leaf explants. Another gene we have characterized from petunia codesfor a cytokinin binding protein (PETCBP). Preliminary functional analysis of this gene indicated that this also affects adventitious shoot bud initiation. Also, the antisense suppression of this gene in petunia causedexcessive branching. Results from our work and selected other publications will be used to highlight the possibilities of manipulation of such genes to improve crop species.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.107-117
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• 2020

Flower industry is now growing due to the development of economy in many countries. Simultaneously, needs from consumers in flower market are varied widely. To satisfy the needs from consumers and deal with a variety of diseases from a lots of pathogens as well as climate change, new elite flower cultivars should be released in flower market. For this purpose, conventional and biotechnological techniques can be employed to make good cultivar. Therefore, this review describes the general overview of flower breeding techniques including cross-hybridization, mutation breeding and genetic transformation systems. Also, breeding systems for ornamentals derived from plant tissue culture such as embryo culture, in vitro fertilization, ovary/ovule culture and haploid production were reviewed. Furthermore, in this study recent development of the generation of new flower cultivars using marker-assisted breeding, plant transformation including particle bombardment and Agrobacterium tumefaciens as well as genome-editing technology were described. This review will be contributed to the development and releasement of new flower cultivars with horticulturally useful traits in the future.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.211-214
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• 1994

Paulowina witches'-broom mycoplasma-like organism (PWB-MLO) was transmitted experimentally to periwinkle (Catharanthus roseus L.) plant by tobacco leaf bug (Cyrtopeltis tenuis Reuter). Adults of the leaf bugs were allowed to feed on the witch's-broom infected paulownia (Paulownia tomentoas Steud.) trees for three weeks to insure the acquisition of PWB-MLO and then transferred to healthy seedlings of periwinkle and paulownia plants. In 25∼35 days after transfer of the viruliferous leaf bugs, six out of the ten periwinkle plants showed‘little-leaf’symptoms, while the paulowina seedlings remained symptomless. Presence of MLO in the infected periwinkle tissue was diagnosed by fluorescence microscopy and MLO particles were observed under electron microscope, confirming the transmission of PWB-MLO to periwinkle.

• Journal of Life Science
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• v.8 no.6
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• pp.623-626
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• 1998

Conditions for somatic embryogenesis and plant regeneration from stem tissues of Euphorbia pulcherrima were esta-blished. Explants from leaf, petiole, stem were examined for their embryogenesis on MS solid medium supplemented with plant growth hormones in combination at various concentrations. From leaf or petiole explants, callus was indu-ced well but never proceeded to the embryonic stage in our expermental conditions. From stem explants, however, multiple shoots following callus induction emerged in about 6 to 8 weeks on MS agar medium supplemented with 1.5 mg/L of benzyladenine. Upon transfer, roots were developed on hormone-free MS solid medium.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.315-318
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• 2007

An effective rapid propagation method was established through in vitro cultures of the medicinal plant, Cudrania tricuspidata. In vitro plantlets were obtained from in vitro germinated seeds. The various levels of cytokinins (BAP, Kinetin and TDZ) were tested on multiple shoot formation from plantlets. BAP (1.0 mg/l) treatment induced highest number of multiple shoots. Single shoot cultures gave higher initial shoot numbers than 5 shoots per culture. Among the various culture media, the shoot elongation was optimal on 2 MS basal medium without growth regulators. The IAA (2.0 mg/l) treatment induced highest number of roots. IBA (2.0 mg/l) treatment more promoted in vitro root growth than other concentrations. Rooted shoots were transferred directly to small pots with an artificial soil and successfully acclimatized.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.47-50
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• 2000

In suspension cultures of Streptanthus. the uptake rate of sugar was increased during the ceil starvation of sugar in the medium. The maximal uptake rate obtained with 3 days of cell starvation. Sugar transport system induced by the sugar starvation was completely inhibited by 10 $\mu$M cycloheximide. Plant cells are known to possess only one sugar transport system, but the uptake rate of glucose obtained a saturated kinetic while the one of sucrose had two different kinetics after the sugar starvation. Induced sugar transport systems had different kinetics compared to plant cell. These results showed that higher plants have adaptable ability to induce new sugar transport systems when the environment changed unsuitable.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.411-413
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• 2000

The ability of microspores or young pollen grains (male gametophytes) to undergo developmetal switch to embryogenic (sporophytic) pathway exemplifies the concept of totipotency as applied to haploid posmeiotic cells. As a first step pollen is devoid of positional information provided in situ by the intact anther - by isolation and cultivation in vitro in artificial media. This is inevitably accompanied by some degree of stress response in microspore/pollen. It has been shown in both monocots and dicots that intentional stress treatment (mostly starvation or heat shock) greatly stimulates embryo induction rate. Using transgenic sHSP antisense Nicotiana tabacum we show that expression of small heat shock proteins is an integral part of successful embryo and later haploid plant production from pollen grains. Our recently published data show that sHSP chaperone function is optimal in the absence of ATP.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.367-373
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• 2000

We have constructed a molecular linkage map of chili pepper (Capsicum spp.) in an interspecific (C. annuum cv. TF68 x C. chinense cv. Habanero) F$_2$ population of 107 plants with 150 RFLP and 430 AFLP markers. The resulting linkage map consists of 11 large (206-60.3 cM) and 5 small (32.6- 10.3 cM) linkage groups cover-ing 1,320 cM with an average map distance between framework markers of 7.5 cM. Most (80%) of the RFLP markers were pepper-derived clones and these markers were evenly distributed across the genome. By using 30 primer combinations, 444 AFLP markers were generated in the F$_2$population. The majority of the AFLP markers clustered in each linkage group, although PstI/MseI markers were more evenly distributed than Eco RI/MseI markers within the linkage groups. Genes for biosynthesis of carotenoids and capsaicinoids were mapped on our linkage map. This map will provide the basis of studying secondary metabolites in pepper.

• Journal of Plant Biotechnology
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• v.5 no.4
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• pp.201-207
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• 2003

Tissue culture techniques arguably are an important approach for ex situ conservation of rare and endangered plant species. However, there is utmost importance on maintaining the genetic integrity of the introduced plants especially in tree species. To examine the genetic integrity of the micropropagated plants, we randomly screened few hardened plants of Syzygium travancoricum, a critically endangered tree taxon, using Randomly Amplified Polymorphic DNA (RAPD) markers. Twenty-three random. primers were tried and twenty-five polymorphic loci were identified. The dendrogram based on the Unweighted Pair-Group Method Arithmetic Average and Nei's similarity index depicted about 97% homology between the mother plants and micropropagated plants. Further, an attempt was made to reintroduce the micropropagated plants in the wild. Over three hundred small trees could be successfully established.