• 한국식물학회:학술대회논문집
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• 한국식물학회 1985년도 워크샵 및 심포지엄 북한산국립공원의 식생
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• pp.35-48
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• 1985

Plastids, which are organelles unique to plant cells, bear their own genome that is organized into DNA-protein complexes (nucleoids). Regulation of gene expression in the plastid has been extensively investigated because this organelle plays an important role in photosynthesis. Few attempts, however, have been made to characterize the regulation of plastid gene expression at the chromosomal structure, using plastid nucleoids. In this report, we summarize the recent progress in the characterization of DNA-binding proteins in plastids, with special emphasis on CND41, a DNA binding protein, which we recently identified in the choloroplast nucleoids from photomixotrophically cultured tobacco cells. CND41 is a protein of 502 amino acids which consisted of a transit peptide of 120 amino acids and a mature protein of 382 amino acids. The N-terminal of the 'mature' protein has lysine-rich region which is essential for DNA-binding. CNA41 also showed significant identities to some aspartyl proteases. Protease activity of purified CND41 has been recently confirmed and characterized. On the other hand, characterization of accumulation of CND41 both in wild type and transgenic tobacco with reduced amount of CND41 suggests that CND41 is a negative regulator in chloroplast gene expression. Further investigation indicated that gene expression of CND41 is cell-specifically and developmentally regulated as well as sugar-induced expression. The reduction of CND41 expression in transgenic tobacco also brought the stunted plant growth due to the reduced cell length in stem. GA3 treatment on apical meristem reversed the dwarf phenotype in the transformants. Effects of CND41 expression on GA biosynthesis will be discussed

• 식물조직배양학회지
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• 제26권2호
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• pp.133-136
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• 1999

미선나무의 기내번식을 위하여 MS배지에 세 가지 싸이토키닌 (zeatin, kinetin 및 BA)을 세 가지 농도로 처리하여 액아 배양을 실시하였다. 줄기유도는 BA가 가장 효과적이었고, 생장은 zeatin이 좋았다. Kinetin은 2.0 및 5.0 mg/L 처리에서 줄기발생 효과가 있었으나 그 효과는 zeatin, BA에 비해 저조했다. 500 lux정도의 약광 하에서 배양은 싸이토키닌 처리에 관계없이 줄기의 생장을 촉진하였다. 발근은 IBA가 첨가된 1/2 GD배지에서 주효했다. 발근된 개체는 인공배양토에서 100% 활착되었고, 정상 생장이 가능했다. 이상의 결과에서 미선나무의 기내 번식이 가능함을 보여 주었다.

• The Plant Pathology Journal
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• 제35권1호
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• pp.84-89
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• 2019

Two-component systems (TCSs) are critical to the pathogenesis of Xanthomonas oryzae pv. oryzae (Xoo). We mutated 55 of 62 genes annotated as responsive regulators (RRs) of TCSs in the genome of Xoo strain PXO99A and identified 9 genes involved in Xoo virulence. Four (rpfG, hrpG, stoS, and detR) of the 9 genes were previously reported as key regulators of Xoo virulence and the other 5 have not been characterized. Lesion lengths on rice leaves inoculated with the mutants were shorter than those of the wild type and were significantly restored with gene complementation. The population density of the 5 mutants in planta was smaller than that of PXO99A at 14 days after inoculation, but the growth curves of the mutants in rich medium were similar to those of the wild type. These newly reported RR genes will facilitate studies on the function of TCSs and of the integrated regulation of TCSs for Xoo pathogenesis.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.189-189
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• 2022

Soil salinity negatively affects plant growth, productivity, and metabolism. Rice is known to have more sensitive phenotypes than other cereal crops, such as wheat, sorghum, and barley. We characterized the molecular function of rice C3HC4 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under normal conditions, there is no significant phenotypic difference between transgenic plants and WT plants. However, OsRFPH2-3-overexpressing plants exhibited higher fresh weight and length under saline conditions. Also, transgenic plants maintain higher chlorophyll, proline, and soluble sugar contents and lower H₂O₂ and MDA contents than the wild type; these results support transgenic plants with enhanced salinity tolerance phenotypes.

• Journal of Plant Biotechnology
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• 제50권
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• pp.225-231
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• 2023

Cold stress is one of the most vulnerable environmental stresses that affect plant growth and crop yields. With the recent advancements in genetic approaches using Arabidopsis and other model systems, genes involved in cold-stress response have been identified and the key cold signaling factors have been characterized. Exposure to low-temperature stress triggers the activation of a set of genes known as cold regulatory (COR) genes. This activation process plays a crucial role in enhancing the resistance of plants to cold and freezing stress. The inducer of the C-repeatbinding factor (CBF) expression 1-CBF module (ICE1-CBF module) is a key cold signaling pathway regulator that enhances the expression of downstream COR genes; however, this signaling module in Panax ginseng remains elusive. Here, we identified cold-signaling-related genes, PgCBF1, PgCBF3, and PgICE1 and conducted functional genomic analysis with a heterologous system. We confirmed that the overexpression of cold- PgCBF3 in the cbf1/2/3 triple Arabidopsis mutant compensated for the cold stress-induced deficiency of COR15A and salt-stress tolerance. In addition, nuclearlocalized PgICE1 has evolutionarily conserved phosphorylation sites that are modulated by brassinsteroid insensitive 2 (PgBIN2) and sucrose non-fermenting 1 (SNF1)-related protein kinase 3 (PgSnRK3), with which it physically interacted in a yeast two-hybrid assay. Overall, our data reveal that the regulators identified in our study, PgICE1 and PgCBFs, are evolutionarily conserved in the P. ginseng genome and are functionally involved in cold and abiotic stress responses.

• 생물환경조절학회지
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• 제14권4호
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• pp.275-279
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• 2005

백침계 오이는 측지착과형으로 주지착과형인 국내용 오이와 차이가 있어 백침계 오이의 수량을 증가시키기 위해서는 측지발생을 높여야 가능하다. 그러나 백질계 오이의 재배시기는 대부분 동절기로 저온 및 일조부족 등의 불량한 환경조건 때문에 측지발생이 떨어진다. 본 연구는 생장조정제를 이용하여 백침계 오이의 측지발생을 촉진하기 위하여 BA의 농도 및 살포시기를 구명하고자 하였다 BA $30mg{\cdot}L^{-1}$을 살포한 것은 농도 장해증상이 억제작형에서는 나타났으나, 반촉성작형에서는 경미하게 나타났다. 측지발생은 BA $10mg{\cdot}L^{-1}$ 살포하는 것이 BA $30mg{\cdot}L^{-1}$ 살포하는 것 보다 많았고, 처리시기는 본엽 10매, 15매 전개되었을 메 살포한 것이 본엽 5매 전개되었을 때 살포한 것보다 많았다.

• 생물환경조절학회지
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• 제12권3호
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• pp.139-146
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• 2003

본 연구는 공정육묘시 triazole계 약제처리가 과채류의(토마토, 오이 및 고추) 묘 도장억제에 미치는 영향을 구명하고, 도장억제에 가장 효과적인 약제를 선발하며, 또한 선발된 약제의 과채류 적정 처리농도와 처리시기를 구명하고자 수행하였다. Triazole계 약제는 품목과 관계없이 농도가 증가할수록 줄기 신장을 억제시켰다. 약제 별 품목별로 diniconazole 처리가 높은 왜화율을 보였으며, tebuconazole과 hexaconazole도 좋은 왜화 효과를 보였다. Diniconazole 처리에 있어서 처리 농도가 증가함 따라 오이, 토마토 및 고추의 초장이 감소하였는데, 오이의 경우 5mg${\cdot}L^{-1}$ 에서 30% 왜화율을 보였으며 100mg{\cdot}L^{-1}$ 에서는 약 60% 의 왜화율이 나타났다. 또한 토마토와 고추에서는 처리시 기와 관계없이 25mg${\cdot}L^{-1}$ 처리구서 3096 왜화효과를 보았다. 공정육묘시 diniconazole 처리를 할 경우 오이 와 토마토는 5mg${\cdot}L^{-1}$ 농도를 2차 생육단계에서, 고추는 5mg${\cdot}L^{-1}$ 농도를 1차 생육단계에서 처리하면 건실한 묘를 얻을 수가 있었다.

• Plant Biotechnology Reports
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• 제5권2호
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• pp.187-195
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• 2011

The gesneriaceous perennial plant Titanotrichum oldhamii has beautiful foliage and attractive bright yellow flowers. However, breeding of T. oldhamii by conventional sexual hybridization may be difficult because sexual reproduction of this species is very rare. In the present study, plant regeneration systems via both direct and indirect formation of adventitious shoots from leaf explants were established as the first step toward breeding T. oldhamii by using biotechnological techniques. Adventitious shoots were formed efficiently on medium containing $0.1mg\;l^{-1}$ benzyladenine. Histological observation showed that shoot formation on this medium occurred directly from leaf epidermal cells without callus formation. On the other hand, leaf explants formed calluses on medium containing $0.1mg\;l^{-1}$ 2,4-dichlorophenoxyacetic acid. The calluses could be maintained by monthly subculturing to fresh medium of the same composition. When the calluses were transferred to plant growth regulator-free medium, they formed adventitious shoots. Directly and indirectly formed shoots rooted well on medium containing $0.1mg\;l^{-1}$ indole-3-butyric acid. Plantlets thus obtained were successfully acclimatized and grew vigorously in the greenhouse. Flow cytometry analysis indicated that no variation in the ploidy level was observed in plants regenerated via direct shoot formation, whereas chromosome doubling occurred in several plants regenerated via indirect shoot formation. Regenerated plants with the same ploidy level as the mother plants showed almost the same phenotype as the mother plants, whereas chromosome-doubled plants showed apparent morphological alterations: they had small and crispate flowers, and round and deep green leaves.

• Journal of Plant Biotechnology
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• 제36권2호
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• pp.137-143
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• 2009

An efficient system for high frequency plant regeneration was established through investigating various factors such as plant growth regulator combinations, explant types and ages, and addition of $AgNO_3$ influenced on shoot regeneration in Brassica juncea L. cv. BARI sarisha-10. Murashige and Skoog (MS) medium supplemented with 0.1 mg/L NAA (1-naphthaleneacetic acid) and 1 mg/L BA (6-benzyladenine) showed the maximum shoot regeneration frequency (56.67%) among the different combinations of NAA and BA. Explant type, explant age, and addition of $AgNO_3$ also significantly affected shoot regeneration. Of the four type of explants (cotyledon, hypocotyl, root, and leaf explants)- cotyledon explants produced the highest shoot regeneration frequency and hypocotyls explants produced the highest number of shoots per explant, whereas root explants did not produce any shoot. The cotyledonary explants from Four-day-old seedlings showed the maximum shoot regeneration frequency and number of shoots per explant. Shoot regeneration frequency increased significantly by adding $AgNO_3$ to the medium. Two mg/L $AgNO_3$ appeared to be the best for shoot regeneration with the highest shoot regeneration frequency (86.67%) and number of shoots per explant (7.5 shoots). Considerable variation in shoot regeneration from cotyledonay explants was observed within the B. juncea L. genotypes. The shoot regeneration frequency ranged from 47.78% for cv. Shambol to 91.11% for cv. Rai-5. In terms of the number of shoots produced per explant, B. juncea L. cv. Daulot showed the maximum efficiency. MS medium supplemented with 0.1 mg/L NAA showed the highest frequency of rooting. The regenerated plantlets were transferred to pot soil and grown to maturity in the greenhouse. All plants were fertile and morphologically identical with the source plants.

• 한국약용작물학회지
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• 제14권1호
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• pp.31-35
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• 2006

Agrobacterium rhizogenes ATCC15834에 의해 형질전환된 지황 (Rehmannia glutinosa)의 모상근으로부터 유식물체를 재분화 시키기 위한 최적 조건을 탐색하였다. 모상근 절편으로부터 유식물체의 재분화는 0.5 mg/l BA가 첨가된 SH배지 (3% sucrose, pH 5.8)에서 배양 5주 후 이루어졌다. 이와 같은 유식물체는 식물생장조절물질이 포함되지 않은 기본배지로 옮겼을 때 발근이 이루어졌다. 형질전환된 모상근 유래 식물체는 잎으로부터 직접 재분화된 식물체와 비교했을 때 잎이 오므라드는 경향을 보였고 줄기는 절간이 짧았으며, 뿌리는 가늘고 수량이 많은 특징을 보였다. 생체량 비교에서 형질전환식물체는 식물 하나의 무게가 1.28 g (생중량)으로 대조구인 잎 유래 재분화식물체 (0.53 g)에 비해 높았으며, 지표물질인 catalpol의 함량에 있어서도 차이를 보여주었다.