• Proceedings of the Botanical Society of Korea Conference
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• 1996.07a
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• pp.10-18
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• 1996

Recently, we have reported a rice MADS-box gene, OsMADS1, as a molecular factor triggering flower formation; this has been well studied in a heterologous system (Chung et al., 1994). In order to study whether the OsMADS1 homolog exists in other plant species, the OsMADS1 cDNA was used as a probe to screen a tobacco cDNA library, and a potential homolog, NtMADS3, was isolated. Sequence analysis revealed that the gene shares 56.1% identity in whole amino acids with OsMADS1. Like OsMADS1, the NtMADS3 gene starts to express at a very early stage of flower development, and the expression continues up to flower maturation. In the tobacco flower, the gene is expressed in whorl 2,3 and 4, corresponding to the petal, stamen, and carpel, respectively. Upon ectopic expression in the homologous system, NtMADS3 caused a trasition from inflorescence shoot meristem into floral meristem, reducing flowering time dramatically. These phenotypes strongly suggest the NtMADS3 gene is the OsMADS1 homolog of tobacco. Hybrids between the OsMADS1 and the NtMADS3 plants were also generated. The hybrids flowered even earlier than these two transgenic plants. The detailed studies are discussed here.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.70-79
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• 1977

Perennial weeds which were grown in transplanted paddy field formed their tubers under shortday condition. Under short day treatment, the induction periods for tuber formation were different depending upon the weed species. 80% cut tubers of the weeds did not loose their developing ability perfectly. Emergence also affected by soil conditions and depths covered.

• The Plant Pathology Journal
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• v.38 no.4
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• pp.403-409
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• 2022

In biological particles such as Fusarium species, ice nucleation activity (INA) has been observed. Fusarium strains isolated from apple declined trees in Korea were identified with a multilocus sequence analysis using the tef1 and rpb1 genes. Droplet-freezing and tube-freezing assays were used to determine the INA of the strains, using Pseudomonas syringae pv. syringae KACC 21200 as a positive control and resulting in seven INA+ fungal strains that were identified as F. tricinctum (KNUF-21-F17, KNUF-21-F18, KNUF-21-F29, KNUF-21-F32, KNUF-21-F38, KNUF-21-F43, and KNUF-21-F44). The effect of Fusarium INA+ KNUF-21-F29 was compared to that of INA- strains on Chrysanthemum morifolium cv. Shinma explants. A higher callus formation and no-shoot formation were observed, suggesting that fungal INA could play a role in cold injuries and be a factor to consider in rapid apple decline. To the best of our knowledge, this is the first report of INA fungal strains isolated in Korea.

• Korean Journal of Plant Resources
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• v.35 no.6
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• pp.770-777
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• 2022

The main objective of this study was to identify the most appropriate condition for root formation of in vitro micropropagated pear (Pyrus spp.) plants. In vitro propagation was induced on Murashige and Skoog (MS) medium with 2.0 mg/L of N6-benzyladenine (BA) and 0.2 mg/L of Indole-3-butyric acid (IBA) medium. The short pre-treatment of explants with a high concentration (1 mg/L) of NAA and IBA (R0 medium) in dark for three days, followed by transfer to five different media (R1 to R5) resulted in good rooting responses in the pear 'Oharabani (P. pyrifolia × P. communis)' genotype. For the rooting experiments, the highest rooting percentage (83.3 ± 8.3%), average root length (3.6 ± 1.9 mm), total root number (31 ± 4.0), and average root number per plant (2.6 ± 2.1) were obtained on half strength (1/2) of MS medium supplemented with 30 g/L sucrose without hormones and activated charcoal (AC) (R1 medium). The highest rooting percentage was obtained at 83.3% from explants on R1 and R3 media. The rooting procedure described in this study resulted in good root formation and significantly shorting the root induction time to within 14 days of culture. Further studies are underway to test the suitability of the protocol developed in this study for other pear genotypes.

• The Korean Journal of Ecology
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• v.22 no.2
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• pp.89-94
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• 1999

Thirty-day-old seedlings of tomato (Lycopersicon esculentum) were treated with different concentrations of HgCl$_2$(0. 10 and 50 $\mu$M) for up to 20 days. and the detailed distribution of Hg absorbed and its toxicity in different plant parts (roots, stems and leaves) were investigated. The accumulation of Hg in plants increased with external Hg concentrations. and Hg is strongly retained by roots. Further. Hg content in leaves was various. showing more accumulation in older leaves. Seedlings exposed to toxic levels of Hg showed not only the reduction of dry weight and length of both shoot and root. and chlorophyll levels in leaves but also the enhancement of malondialdehyde (a lipid peroxidation product) formation in all plant parts investigated. These results suggest that physiological impairment of a plant exposed to Hg may be achieved by internal distribution of Hg absorbed and Hg-induced oxidative stress in different plant parts.

• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.87-91
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• 2006

An efficient plant regeneration of C. asiatica was achieved from organogenesis using petiole explants of in vitro plantlet on MS basal medium controled with different plant growth regulators (NAA,2,4-D, IAA kinetin, and BA). Best results that 50%, efficiency of regeneration per explant for regeneration were obtained with IAA $17.13\;{\mu}M$ and BA $8.9\;{\mu}M$. Formation of adventitious shoots via organogenesis from the petiole explant was verified by histological sectioning of plantlets. Regenerated plants were transplanted into soil.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.10a
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• pp.80-80
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• 2003

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.27-34
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• 2010

To obtain the basic information for the use of bamboo, the anatomical characteristics of moso bamboo shoots, and 20-day-old, 60-day-old, one-year-old, and two-year-old moso bamboo were observed by using polarizing microscope. The cross section showed that the bamboo shoots consists of the early stage of cell formation, atactostele, parenchyma, and bundle sheath was formed in 20-day-old moso bamboo, and all cells completely formed in 60-day-old moso bamboo. The tissues in one-year-old moso bamboo appeared to be completely matured. On the tangential surface, no atactostele was observed in the bamboo shoot, but metaxylem, parenchyma, and bundle sheath were found. atactostele and parenchyma appeared to be formed between 20 and 60 days. All tissues and cells were totally formed and the cell wall of parenchyma were completely matured after one year. The metaxylem in bamboo shoots was observed to have pits, which means that it could be the tissues first formed of all bamboo cells.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.249-252
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• 2002

Several plant growth regulators were examined for on their effect on the in vitro propagation of Kalopanax pictus$(T_{HUNB}.)$ $(N_{AKAI}.)$ on WPM medium. Among the cytokinins tested, BA at $13.32\;{\mu}M$ appeared to be the most effective for multiple axillary shoot formation. Although the addition of $2.89\;{\mu}M\;GA_3$ promoted stem elongation, it produced morphologically abnormal leaves and stems. For rooting of the shoots, $4.9\;{\mu}M$ IBA seemed to be more effective than $2.69\;{\mu}M$ NAA. When the regenerated plants were transferred on artificial mixture containing vermiculite and peat-moss (1 : 1, v/v), 81% of them survived and grew normally.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.269-271
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• 2005

본 연구는 수선화 구근의 각 조직으로부터 기내배양시 캘러스형성과 신초재분화를 위한 성장조절제의 효과를 측정하기 써하여 시행되었다. 신초형성과 callus의 형성은 기저부를 포함하는 floral axis에서 $50\%$의 신초발아율을 관찰하였고 scale 에서는 신초형성이 거의 관찰되지 않았다. 그리고 floral axis만을 치상한 경우는 아주 저조한 신초형성율이 관찰되었다. 지저부를 포함한 floral axis의 신초형성은 callus의 형성과 같은 NAA 0.5 mg/L과 BA 1.0 mg/L을 포함하는 MS 배지에서 만족할만한 결과를 얻었다. 신초형성으로부터 모든 신초가 형성되기까지는 약 140일이 소요되었다. 신초가 형성된 구근조직을 NAA 5.0 mg/L과 TDZ 0.02 mg/L을 포함하는 뿌리유도 MS배지에서 뿌리가 유도되는 결과를 얻었다. 본 실험에서는 수선화의 재 분화에 있어서 구근의 조직에 따라 신초형성이 다르게 나타남을 발견 할 수 있었다.