• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.305-308
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• 1998

Leaf and petiole explants of kiwifruit were cultured on MT basal medium supplimented with 2,4-D, kinetin, NAA, and BA. Higher organogenic callus formation was observed on the media with NAA + BA than on the media added with 2,4-D + kinetin. Adventitious buds were formed only on media with NAA and BA. Leaf was better explant than petiole. When callus and adventitious buds were subcultured, shoot formation responsed best on medium with 0.1 mg/L NAA + 2.0 mg/L zeatin. When shoots were cultured on medium with 0.5 mg/L IAA + 0.1 mg/L BA after soaking for 1 hr at IBA solution, rooting was more effective than non-IBA treatment. Rooted shoots developed into normal plants.

• International Journal of Oral Biology
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• v.37 no.2
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• pp.51-56
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• 2012

Tooth development involves bud, cap, bell and hard tissue formation stages, each of which is tightly controlled by regulatory molecules. The aim of this study was to identify genes that are differentially expressed during dental hard tissue differentiation. Sprague-Dawley rats at postnatal days 3, 6 and 9 were used in the analysis. Differential display RT-PCR (DD-PCR) was used to screen differentially expressed genes between the 2nd (root formation stage, during mineralization) and 3rd (cap stage, before mineralization) molar germs at postnatal day 9. The DNA detected in the 2nd molar germs showed homology to osteonectin only (GenBank accession no. NM_012656.1). The level of osteonectin mRNA expression was much higher in the 2nd molar germs than in the 3rd molar germs and was found to increase in a time-dependent manner from the early bell stage to the root formation stage in the 2nd molar germs. The pattern of osteonectin protein expression was consistent with these RT-PCR results. Osteonectin protein was found by immunofluorescent analysis to localize in odontoblasts and preodontoblasts rather than the dentin matrix itself. Further studies are needed to validate the involvement of osteonectin in mineralization and root formation.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.138-145
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• 2016

To find the optimal propagation condition for endangered Cypripedium macranthos Sw., also known as lady's slipper orchid, the effect of various organic additives on in vitro germination, protocorm formation and seedling growth was investigated during asymbiotic seed culture. When $100ml{\cdot}L^{-1}$ coconut water was added to the basal medium, the highest germination rate and protocorm formation rate were achieved, with 70.8% and 74.2% respectively. Supplementation of phloem sap from birch tree or maple tree also showed a facilitating effect to improve the germination and protocorm development. With $100ml{\cdot}L^{-1}$ birch sap or maple sap, both the germination and protocorm formation rates were roughly more than 65% and 68%. The roots and buds of the seedlings grew vigorously in the medium containing $100ml{\cdot}L^{-1}$ coconut water or phloem sap, in particular, their bud formation rates increased by more than 70%. Addition of banana powder and peptone could not create a more significantly favorable culture condition, and non-addition had the worst results. Our results demonstrated that proper organic amendments such as coconut water and phloem sap might be preferred to in vitro germination and the growth of seedlings developed from the protocorm of C. macranthos Sw. during asymbiotic seed culture.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.132-137
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• 2016

The genus Cypripedium, known as lady's slipper orchid, has been considered to have a considerable marketability as a potted and garden plant with beautiful flowers; however, this species is becoming endangered and, in some places extinct, due to habitat destruction and illegal collections. As such, an optimized artificial propagation system is necessary for its conservation and horticultural cultivation. For the establishment of the in vitro proliferation of the endangered Cypripedium macranthos Sw., native to Korea, the effects of medium strength and sucrose concentrations on germination, protocorm formation and seedling growth were investigated through asymbiotic seed culture. The highest germination rate and protocorm formation rate were obtained with a 1/4 MS medium; higher MS medium strengths did not generate the favorable conditions required for germination and protocorm growth. The overall growth characteristics of roots and buds developed from protocorms were best in cultures of 1/4 MS medium. On this medium containing $10g{\cdot}L^{-1}$ sucrose, both the germination rate and protocorm formation rate increased significantly. The general growth properties of seedlings developed on the medium with $10g{\cdot}L^{-1}$ sucrose were best, showing the highest bud formation rate and root number. Our results demonstrate that the 1/4 MS medium, supplemented with $10g{\cdot}L^{-1}$ sucrose, could improve in vitro germination, and facilitate the growth of seedlings developed from the protocorms of C. macranthos Sw.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.352-357
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• 2001

This experiment was carried out in order to develop some chip budding techniques related to the production of high quality maiden apple trees. Optimum chip budding time for apple trees appeared to be from mid-August to early September. Untying wrapping tapes after 6 8 weeks from budding led to higher graft success and better shoot growth than removing the tapes earlier or later than the 6-8 weeks. Dipping pre-cut bud chips into ordinary water of $25^{\circ}C$ for 5 hours did not hamper the graft-success nor the early season growth of the graft compared with non-treated control. Dipping the pre-cut bud-chips into the $35^{\circ}C$ water for 3 hours or for 5 hours hampered the union formation and shoot growth of the 'Fuji' apple trees.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.360-364
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• 2006

The gametophytes of Cyrtomium falcatum and Cyrtomium caryoptideum var. coreanum arising from spores were mechanically homogenized and cultured In vitro, to study their gametophyte ontogeny and sporophyte development. Homogenized gametophytic tissues formed as one-dimensional filaments after 2 weeks in culture and then glowed into blanched gamatophytes after 4 weeks. After 6 weeks, which were developed to two dimensional plates with apical notch and meristem in central zone. After 8 weeks in culture, apomictic buds were formed on the midribs without archegonium formation and these buds developed to sporophytes after 10 weeks in culture. Flow cytometric analysis of gametophytes and apomictic sporophytes revealed that both forms had the same ploidy level in C. falcatum and C. caryoptideum vu. coreanum, respectively. This is to certify that C. caryoptideum var. coreanum was an apomictic fern as well as C. falcatum.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.265-272
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• 2006

This study was conducted to investigate the efficient propagation method of Cyrtomium caryoptideum var. coreanum by sporophyte culture. The influence of origin of explant sources (rhizome, blade, or stipe) and homogenization of culture materials on shoot regeneration were investigated. As a result, only rhizome explant exhibited the organogenic capacity and the shoot regeneration was promoted by homogenization of culture material. Vigorous and excellent growth of multiple shoots was induced on the half-strength of inorganic salts containing MS medium. It was appeared that optimum nitrogen content of shoot regeneration was half-strength of nitrogen containing MS medium (30mM) and optimum sucrose concentration was 1%. Addition of $NaH_2PO_4$ to culture medium generally enhanced shoot multiplication and promoted growth of the regenerants. The organogenic capacity of homogenized rhizomes was especially promoted on medium supplemented with $5{\mu}M$ kinetin plus $5{\mu}M$ IBA. The incorporation of $0.1\sim0.2%$ activated charcoal on medium supplemented with growth regulators prevented the formation of multiple bud primordia - nodule-like bud clusters and improved the normal morphogenesis of sporophytes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.363-367
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• 2004

The deep irrigation of rice plants brings about some beneficial effects such as reduced tiller production which results in the formation of bigger panicles, prevention of chilling injury, reduced weed growth, etc. The present study was carried out to examine the involvement of ethylene in the suppression of tiller production due to deep water irrigation in rice (cv. Dongjinbyeo). The ethylene production was induced in leaf sheath within 24 hours after the deep water irrigation and has increased even until 30 days after the treatment, recording 4.5-fold increase as compared to the shallow-irrigated rice plants. In the deep water irrigated rice plants, ethylene was accumulated to a high concentration in the air space of submerged leaf sheath as the irrigated water deterred the diffusion of ethylene out of the leaf sheath and ethylene biosynthesis was accelerated by the deep irrigation as well. The ethylene concentration recorded 35-fold increase in the deep-irrigated rice plants for 35 days. The tiller production was reduced significantly by the deep irrigation with water, the tiller bud, especially tertiary tiller bud differentiation being suppressed by the deepwater irrigation treatment, whereas the rice plants deep-irrigated with solutions containing $10^{-5}$ M or $10^{-6}$ M silver thiosulfate (STS), an action inhibitor of ethylene, showed the same or even higher production of tillers than those irrigated shallowly with water. This implies that the ethylene is closely linked with the suppression of tiller production due to deep water irrigation. In conclusion, ethylene, which was induced by hypoxic stress and accumulated in the leaf sheath due to submergence, played a key role in suppressing the tiller production of the deepwater irrigated rice.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.111-115
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• 2008

Vitamin D-dependent rickets(VDDR) is a rare autosomal disorder, characterized by hypocalcemia, hypophosphatemia, increased alkaline phosphatase, secondary hyperparathyroidism and many other clinical features. Type I VDDR is due to congenital defects of renal 1${\alpha}$-hydroxylase, the enzyme responsible for the conversion of 25-(OH)D3 to 1,25-$(OH)_2D3$. Type II VDDR arise from target organ resistance to 1,25-$(OH)_2D3$. Unilateral renal aplasia is generally thought to result from a lack of induction of the metanephric blastema from the ureteral bud, which may be secondary to ureteral bud maldevelopment and/or to a problem with the formation of the mesonephric duct. The incidence of unilateral renal aplasia is approximately 1/500-3,200. Type 1 VDDR associated with unilateral renal aplasia has not been reported yet. Thus we report a case of a 3 month old female infant diagnosed as type 1 VDDR with unilateral aplasia of kidney.

• Korean Journal of Medicinal Crop Science
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• v.11 no.2
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• pp.122-126
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• 2003

This study was conducted to investigate plant growth characteristics and anatomical studies of Korean mistel (Viscum album var. coloratum (Kom.) Ohwi). Parasite position was upper part that has a plenty of sunshine area 5 to 10m apart from the ground, regardless host tree. Stem developed two branch stems from the each basal stem, leaf was grown from the end stems as opposite. Fruit has a light yellow color and berry size was 7 to 8 mm long diameter and it contains seed. Floral bud differentiation initiated with forming rounded dome and arch-shaped floral apex at the beginning stage, and produced heart-shaped sepal following the differentiation of leaf primordia. Floral bud formation processed centeral part first and following bilateral sides were developed in order. Leaf was thick and stoma and guard cell were observed from the two or three inner layers from the epidermis. Mistletoe penetrated cork cambium of host plant and was growing by rooting on xylem. Korean mistel connected to host plant through parasitic organ, haustorium structurally and physiologically.