• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.133-144
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• 1993

Calli were induced on microtuber disks of potato(S.tuberosum) infected with three binary vectors transconjugated with C58, A281 and LBA 4404 of Agrobacterium tumefaciens and pBI121. The frequency inducing callus was the highest by infection of C121 carrying pC58 and pBI121, and shoots were differentiated on the calli without any hormonal application. Transformed calli were selected by their resistance to kanamycin and identified by GUS activity. The frequency of callus formation by infection of binary vector strain was affected according to the hormonal application.

• Journal of Bio-Environment Control
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• v.23 no.1
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• pp.31-38
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• 2014

Rooting agents and shading treatments were tested in two different experiments to determine their effects on the establishment success of hardwood cuttings of three highbush blueberry varieties 'Bluecrop', 'Duke' and 'Sunrise'. For the experiment with rooting agents, one-cm long bases of the cuttings were dipped into solutions of IBA or NAA for 5 s, both at 0, 500 and $1000mg{\cdot}L^{-1}$ in 50% ethanol, and were also treated with Rootone$^{(R)}$ powder. Determined 90 days after cutting, the percent rooting and root weight were increased by NAA at $500mg{\cdot}L^{-1}$ in 'Bluecrop' and 'Sunrise', while in 'Duke' IBA at $500mg{\cdot}L^{-1}$ was effective. These auxin treatments were found to work better than a commercial product Rootone$^{(R)}$. The rooting agent-induced increases in root development resulted in better shoot growth of the cuttings in all three varieties, as determined after 90 days of further growth in individual containers. In the experiment with shading treatments, different levels of the shading treatment (30 to 90%) were imposed over the cutting bed under no mist. In all three varieties, 30% shading increased the percent rooting and root and shoot growth, compared to no shading control. However, shading levels higher than 50% shading were found to be inhibitory for hardwood cuttings of highbush blueberries, especially under the environmental conditions with no mist system.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.1-6
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• 2001

The timing for the determination in root formation from nodal and internodal explants of cassava (Manihot esculenta Crantz, cv. MCol 22) was investigated. Nodal explants about 10 mm with an axillary bud formed adventitious roots directly on MS basal medium for 8 days of cultures. But internodal segments without an axillary bud did not develop the adventitious roots on the same medium, and most internodal segments excised from nodal explants after cultures of 5 days on MS basal medium developed adventitious roots. On the other hand, the internodal segments rooted at 90% after cultures on medium with 0.5 mg/L IBA for 5 days, with 1 mg/L IBA for 2.5 days, and with 2 mg/L IBA for 1.5 days respectively. Thus the period of culture on medium with IBA and its IBA concentration affected the rooting rate. Therefore, it is suggested that the determination for root formation occurred before the differentiation of root primordia on medium with IBA, and root inducing factors in medium were absorbed and accumulated during the period of determination for root primordium differentiation in internodal segment of cassava.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.135-153
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• 2015

The aromatic amino acids, which are composed of $\small{L}$-phenylalanine, $\small{L}$-tyrosine and $\small{L}$-tryptophan, are general components of protein synthesis as well as precursors for a wide range of secondary metabolites. These aromatic amino acids-derived compounds play important roles as ingredients of diverse phenolics including pigments and cell walls, and hormones like auxin and salicylic acid in plants. Moreover, they also serve as the natural products of alkaloids and glucosinolates, which have a high potential to promote human health and nutrition. The biosynthetic pathways of aromatic amino acids share a chorismate, the common intermediate, which is originated from shikimate pathway. Then, tryptophan is synthesized via anthranilate and the other phenylalanine and tyrosine are synthesized via prephenate, as intermediates. This review reports recent studies about all the enzymatic steps involved in aromatic amino acid biosynthetic pathways and their gene regulation on transcriptional/post-transcriptional levels. Furthermore, results of metabolic engineering are introduced as efforts to improve the production of the aromatic amino acids-derived secondary metabolites in plants.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.171-171
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• 2017

Propagation by crown division in Platycodon grandiflorum is too slow for producing many plants in a short time although the plants are uniform. This study was performed to enhance the mass propagation for Platycodon grandiflorum containing yellow green petals via various medium compositions and the growth regulators. The nodes containing yellow green petals were used as materials to execute the study with a variety of MS medium concentrations. The 1/4MS medium showed the best development of adventitious root, while the 1/2MS medium exhibited the potential growth. The higher the concentration of sucrose showed the better development and growth of both shoots and adventitious roots. Many adventitious roots were developed at the controlled culture medium at pH 4.8 with a tendency of suppression with higher levels of pH. Also, the cultivated node and leaf explants with the treatments of simple and combined applications with auxin and cytokinin at the 1/4MS culture medium with adding 5% of sucrose were used to identify the influences of growth regulators. The regeneration of plantlets at the 234single application showed a good result with the addition of BA $1mg{\cdot}L^{-1}$ and the development and growth of adventitious roots appeared to be good at the addition of NAA $1mg{\cdot}L^{-1}$. For the combined applications, the regeneration of plantlets and the development of adventitious roots were prosperous at the combined applications with BA $0.1mg{\cdot}L^{-1}$ and IAA $0.5mg{\cdot}L^{-1}$. The addition of IAA for the leaf explants induced a number of plantlets that showed the potential regeneration, and the highest results was obtained from the combined applications of both BA $1mg{\cdot}L^{-1}$ and IAA $2.5mg{\cdot}L^{-1}$. In addition, the development of adventitious roots showed the satisfactory results at the combined application of both BA $1mg{\cdot}L^{-1}$ and IAA $0.5mg{\cdot}L^{-1}$.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.34-39
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• 2007

Whole plants were regenerated from callus induced from leaf explants in hybrid kiwi (Actinidia deliciosa${\times}$A. arguta). Callus was induced from leaf explants which cultured on MS solid medium supplemented with combination of auxin (2,4-D, NAA: 0.1~0.5 mg/l) and cytokinin (BA: 0.1~0.2 mg/l). them, the highest callus formation (96.2%) was obtained from the treatment of 0.5 mg/1 2,4-D+0.1 mg/l NAA+0.05 mg/l BA. In the experiment of adventitious shoots induction from primary shoots, only a few shoots were produced in the treatment of 1.0 mg/l BA+0.05 mg/l IBA or 2.0 mg/l BA+0.05 mg/l lBA. As the callus were transferred to the secondary shoot-inducing medium, multiple shoots were obtained from the medium supplemented with 1.0, 2.0 or 5.0 mg/l zeatin in addition to the mixed treatments of BA, thidiazuron (TDZ) or zeatin. However, no multiple shoots were induced on the BA-contained medium of concentrations. Therefore it turned out that addition of BA to medium was less effective for induction of multiple shoots from callus in Actinidia deliciosa${\times}$A. arguta. For producing adventitious roots from shoots, the best frequency of rooting (83.3%) were recorded on the treatment of in vitro rooting (Standardi (St)+1.0 mg/l IBA). On the other side, the lowest result (40.0%) were shown in the treatment of 500 mg/l IBA, 1 hr. Whole plants with shoots and roots were recovered and acclimatized successfully.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.83-88
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• 2007

Micropropagation of Ulmus davidiana Planch was established via adventitious shoot formation from the segments of adventitious roots. Adventitious roots were produced directly from root segments of seedlings on a 1/2 SH medium plus various concentrations of IBA. The maximum growth of adventitious roots was observed in the presence of 2.0 mg/L IBA. After the segments of adventitious roots were cultured on various cytokinins (zeatin, 2-iP, BA, kinetin) and cytokinins plus auxin (IBA), formation of adventitious shoot was investigated. Among cytokinin treated, kinetin was the most effective on both adventitious shoot induction and number of shoots. Especially, 2.0 mg/L kinetin was the best to increase adventitious shoot induction (95.8%) and a number of shoots (8.4). Adventitious shoots were rooted on 1/2 WPM medium and the plantlets were acclimated 100% on composed soil (peatmoss : vermiculite 1 : 1).

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.16-21
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• 2012

Since many pesticides cause various health and environmental problems, alternative measures to replace them are needed, and the bacteria producing the antifungal substances can be one of them. In this study, several rhizobacteria were isolated and their antifungal activities against some important plant pathogenic fungi were examined. Pseudomonas otitidis TK1 and Paenibacillus peoriae RhAn32 inhibited the growth of Fusarium oxysporum f. sp. niveum and F. oxysporum f. sp. lycopersici by 49.8% and 45.6%, and 45.1% and 48.3%, respectively compared to those of the control. P. peoriae RhAn32 also decreased the growth of F. oxysporum f. sp. raphani by 37.5%. This growth inhibition might be due to the production of antifungal substances, such as siderophore, hydrogen cyanide and chitinase, which were produced by these rhizobacteria. P. otitidis TK1 also produced plant growth hormones indole acetic acid and indole butyric acid at $293.41{\mu}g/mg$ protein and $418.53{\mu}g/mg$ protein, respectively. When P. otitidis TK1 and B. cereus TK2 were inoculated together with F. oxysporum f. sp. lycopersici to the 4 weeks grown tomato seedlings and incubated additional 8 weeks, the stem lengths of tomato increased up to 45.7% and 55.3% and root lengths were raised to 64.9% and 60.8%, respectively than those of the control group. The wet weights increased by 118% and 182%, respectively compared to the control group.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.1-7
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• 2012

This study explores the interaction between the production of indole-3-acetic acid (IAA), a typical phytohormone auxin and the role of IAA biosynthetic pathways in each IAA producing rhizobacterial strain. The bacterial strains were isolated from rhizosphere of wild plants and identified as Acinetobacter guillouiae SW5, Bacillus thuringiensis SW17, Rhodococcus equi SW9, and Lysinibacillus fusiformis SW13. A. guillouiae SW5 exhibited the highest production of IAA using tryptophan-dependent pathways among the 4 strains. When indole-3-acetamide (IAM) was added, Rhodococcus equi SW9 showed the highest IAA production of $3824{\mu}g/mg$ protein using amidase activity. A. guillouiae SW5 also showed the highest production of IAA using two pathways with indole-3-acetonitrile (IAN), and its nitrile hydratase activity might be higher than nitrilase. B. thuringiensis SW17 showed the lowest IAA production, and most of IAA might be produced by the amidase activity, although the nitrilase activity was the highest among 4 strains. The roles of nitrile converting enzymes were relatively similar in IAA synthesis by Lysinibacillus fusiformis SW13. Tryptophan-independent pathway of IAA production was utilized by only A. guillouiae SW5.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.247-252
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• 2002

The combination of radiation technique with an in vitro culture system was initiated to develop salt tolerant rice. We established an in vitro culture system to select tolerant lines against salt stress. NaCl tolerant cell lines were selected from the callus irradiated with gamma ray on N$_{6}$ medium with 1.5% NaCl and 2 mg/L 2,4-D. Regenerants (M$_1$) were obtained from the tolerant callus which was cultured for 30 days auxin-free medium. The M$_2$seeds were harvested from M$_1$plants on an individual plant basis. Thirty seedlings from each 450 M$_2$lines were transplanted in a field and total 5,000 M$_3$lines were harvested with an average 90 percent of fertile grain. M$_3$lines were utilized for selection of salt tolerance. Salinity-tolerant lines (225) were selected among 5,000 M$_3$lines. Of the 225 lines tested, the morphological traits of two lines (120-10 and -11) were far superior to control (Donagjinbyeo) in agromomic traits such as plant height, root length and no. of roots. Control and tolerant lines were analyzed by RAPD markers. Three polymorphic bands were presented in only tolerant lines, demonstrating a genetic difference between control and the tolerant lines. Such tolerant lines could be used as genetic resources to improve salt tolerance.e.