• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.217-221
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• 1995

This experiment was carried out to determine the effects of genotyes (cultivars) and kinds of cytokinins and concentrations on shoot multiplication of roses (Rosa hybrida) by nodal culture. The results from this study were summarized as follows. Shoot multiplication was significantly affected by genotypes. Most shoots were produced from 'Carl Red 'rather than two other cultivars, 'Golden Emblem' and 'Tineke'. Among 3 cytokinins, BA was more significantly effective for multiplication than two other cytokinins, 2iP and kinetin. However subsequent shoot growth after multiplication was more enhanced by 2iP and kinetin rather than BA. An optimal concentration of cytokinin for shoot multiplication was 1 mg/L in this study but BA at 1-5 mg/L was considered optimal for multiplication ratio itself. Subsequent shoot growth was significantly inhibited by increases in cytokinin concentrations, regardless of kinds of cytokinin.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.678-684
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• 2010

In an attempt to improve biomass and bioactive compound production, we cultured adventitious roots of $Eleutherococcus$ $koreanum$ in 250 mL Erlenmeyer flasks using Murashige and Skoog (MS) medium with different concentrations of auxins (IBA, NAA, IAA) and cytokinins (BA, kinetin, TDZ). Root biomass (fresh and dry weight) was enhanced at $5mg{\cdot}L^{-1}$ indole-3-butyric acid (IBA) after 5 weeks of culture. The content of total phenolics and flavonoids was also increased with $5mg{\cdot}L^{-1}$ IBA compared to ${\alpha}$-naphtalene acetic acid (NAA) or indole-3-acetic acid (IAA) treatments. The combination of $5mg{\cdot}L^{-1}$ IBA with $0.1mg{\cdot}L^{-1}$ thidiazuron (TDZ; N-phenyl-N'-1,2,3,-thidiazol-5-ylurea) enhanced root fresh and dry weight (1.4- and 1.6-fold, respectively) as well as the content of total phenolics and flavonoids compared to the relative control (without cytokinin). On the contrary, $N_6$-benzyladenine (BA) and 6-furfurylaminopurine (kinetin) did not significantly affect root biomass and bioactive compound production in adventitious roots of $E.$ $koreanum$. These results suggested that $5mg{\cdot}L^{-1}$ IBA combination with $0.1mg{\cdot}L^{-1}$ TDZ supplementation was most suitable for both biomass and bioactive compound production from adventitious roots of $E.$ $koreanum$.

• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.72-78
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• 2013

To establish an efficient protocol for plant regeneration of Brassica juncea L. Czern, the effects of explant types, explant ages and cytokinins on shoot regeneration were examined in this study. Shoot regeneration was markedly affected by the explant types used in the following order: cotyledon with petiole> hypocotyl> leaf with petiole> cotyledon> leaf. Five-day-old seedlings of cotyledon with petiole explants showed the maximum shoot regeneration frequency. Of the six cytokinins-6-${\gamma}$-${\gamma}$-Dimethylallylamino-purine (2-ip), 6-${\gamma}$-${\gamma}$-Dimethylallylamino-purine riboside (2-ip riboside), 6-Benzyl amino-purine (BAP), Thidiazuron (TDZ), Zeatin, Zeatin riboside-TDZ ($8{\mu}M$) was found to be the best cytokinin for shoot regeneration with the highest shoot induction frequency (80%) from cotyledon with petiole after 4 weeks. All the regenerated plantlets were developed well and they produced morphologically normal flowers.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.185-189
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• 2000

For the micropropagation, node explants of cassava were cultured in liquid MS medium with various concentrations of cytokinins on a rotary shaker (100 rpm) for 2 weeks. The adventitious roots and shoots from the explants were differentiated more efficiently in liquid medium than in solid. But root formation was not inhibited in medium with BAP and kinetin at low concentration (＞0.05 mg 1/sup -1/), while in medium added with BAP and zeatin at high level (＜0.25 mg 1/sup -1/), it was inhibited by callus forming on cut end of the cuttings. However, all of plantlets grown in liquid medium for more than 2 weeks showed symptoms of hyperhydricity. The plantlets grown in liquid medium were transferred into culture bottles filled with fine sand or artificial soil (pitmoss：perlite：vermiculite, 1：1：1 v/v) wetted with half strength of Knop's solution. After transplanted to culture bottles, some of vitriscent leaves were defoliated and new leaves were normally formed from shoot apex. Most of plantlets (＞95%) were hardened-off successfully only in culture bottles with fine sand, and grew into 3-5 cm seedlings possessing 4-6 nodes after 4 weeks. Thus, the mass propagation of cassava on medium containing cytokinin could be established based on the suspension culture using node explants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.438-441
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• 2003

The present study was carried out to assess the possibility of rapid multiplication of Curcuma longa Linne through in vitro culture of shoot-apex. The factor investigated was effect of various growth regulators on shoot-apex culture. The shoot-apex cultured of MS(Murashige and Skoog) medium developed into plantlet in 16 Weeks. M.S. medium containing NAA at 0.5 ppm and BA 5.0 ppm was found to be optimal for growth of in vitro plantlet

• Journal of Life Science
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• v.28 no.10
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• pp.1132-1139
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• 2018

The stability of diverse cellular proteins in eukaryotes is regulated via ubiquitination. Moreover, E3 ligase plays a crucial role in determining substrate specificity and transfers ubiquitins into the substrates during the ubiquitination process. As a type of multi-subunit E3 ligase, cullin4 (CUL4)-based E3 ligase (CRL4) complex is involved in a variety of cellular processes, such as hormonal and stress responses in plants. In spite of several reports on the versatile roles of CRL4 in various signalings in Arabidopsis, CRL4's function in rice has been poorly known. To learn about CRL4-mediated cellular processes in rice in more detail, OsCUL4 that exhibits the highest homology with Arabidopsis CUL4 was isolated, and its expression patterns in various tissues and in response to plant hormones and abiotic stresses were monitored. Exogenous application of ABA or cytokinin increased the transcript levels of the OsCUL4 gene. Moreover, OsCUL4 was significantly upregulated in response to drought and salt stresses. These findings imply that OsCUL4 may be functionally related to ABA- and/or cytokinin-mediated cellular responses. OsCUL4 directly interacted with OsDDB1, an adaptor protein of CRL4, indicating that OsCUL4 can act as a scaffold protein of CRL4. An expression study on the OsCUL4 gene from this report could be used as a starting point to elucidate cellular responses in which a CRL4-mediated ubiquitination process is involved in rice.

• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.32-36
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• 2019

Calla lilies (Zantedeschia spp.) are monocotyledonous ornamental plants which belongs to the Araceae family. After the release of elite calla cultivar, an efficient propagation system is needed for commercial use. Despite the use of conventional propagation methods such as splitting of tubers and rhizomes of calla, rapid and efficient propagation system should be developed. In order to achieve this goal, stem segments contained apical meristems derived from calla lily cultivar (cv. Gag-si) were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of cytokinin and auxin. This was aimed at inducing embryogenic calluses, shoots and multiple shoots. As a result, about 25% of induction rates of yellow embryogenic calluses were observed with MS medium containing both $0.5mg{\cdot}L^{-1}\;NAA$ and $1.5mg{\cdot}L^{-1}\;BA$ as growth regulators. In the experiments involving the regeneration from embryogenic calluses through shoot formation, MS medium supplemented with $0.5mg{\cdot}L^{-1}\;IAA$ and $2.0mg{\cdot}L^{-1}\;BA$ showed the highest rates at approximately 85 ~ 90% with regard to the formation of shoots in calla. Moreover, multiple shoots needed for rapid propagation were generated when explants were cultured on MS medium supplemented with $0.5mg{\cdot}L^{-1}\;IAA$ and $2.0mg{\cdot}L^{-1}\;BA$ with 40% of formation rate. In this study, the combination of auxin and cytokinin showed positive effects on both the induction of embryogenic calluses, the formation of shoots as well as multiple shoots in calla. The regeneration system described here can contribute to the development of breeding programs of calla in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.464-467
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• 2001

In order to establish a in vitro propagation system for gold tree[Dendropanax morbifera $L_{EV}$], the effects of auxins and cytokinins on shoot multiplication and rooting were investigated. Germination rate was the best in MS medium. The fresh weight and number of shoot were the best on the medium containing 0.1 or 1.0 mg/l BAP and 0.5 or 1.0 mg/l NAA. Shoots were successfully rooted in MS medium with 1.0 mg/l NAA. Roots were easily formed by the addition of auxins, especially 0.1 or 1.0 mg/l BAP.P.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.72-77
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• 2017

This study was conducted to examine the effect by application method and concentration of plant growth regulator (PGR) on the growth and runner production of strawberry (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) in a velno-type greenhouse. The seedlings of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial mixed medium (Tosilee) on February 22nd, 2016. The 6-benzylaminopurine (6-BAP) was applied with foliar spray or drench, respectively as 900, 1,200 or $1,500mg{\cdot}L^{-1}$ (50 mL per plant) at 3 weeks after transplanting. Nutrient solution was sufficiently supplied by the drip irrigation as EC $0.65dS{\cdot}m^{-1}$ for rooting during 7 days. After rooting, the 450 mL nutrient solution supplied per pot twice a day (10 min). Plant height and crown diameter of 'Maehyang' mother plant appeared no significantly difference. The other growth characteristics, such as root length, number of primary roots, leaf length, leaf width, leaf area and fresh and dry weights of the shoot or root, were significantly the greatest in the control. And, the SPAD value of strawberry was the highest as 44.2 in the drench with $900mg{\cdot}L^{-1}$. The foiler spray was more effective in runner production than drench, and the number of runners appeared high values at the 900 and $1,500mg{\cdot}L^{-1}$. Whereas, the number of strawberry plantlets was effective in the drench. The results indicate that both growth and the number of runners of strawberry plant were the best achieved by foliar spray application at the $900mg{\cdot}L^{-1}$.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.628-635
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• 2011

This study was conducted to establish the tissue culture system for Korean domestic Miscanthus sinensis, which is used in various purposes such as forage, and bio-energy resources. With the mature seed of Miscanthus, optimum concentrations of plant growth regulators were identified for an efficient callus induction and regeneration. Among the treatments of 1~10 $mg{\cdot}L^{-1}$ 2,4-D, IBA, or NAA, callus induction rate was highest (85.3%) on MS medium containing 5 $mg{\cdot}L^{-1}$ 2,4-D. Under the condition, the callus were efficiently induced and proliferated with comparably lower frequencies of callus browning. In shoot regeneration, the treatment of NAA combined with BAP seemed to contribute more efficient conditions to shoot regeneration than those of NAA with Kinetin or 2-iP. Especially, regeneration efficiency and number of regenerated plants were 83.7% and 5.5 in 3 $mg{\cdot}L^{-1}$ NAA with 5 $mg{\cdot}L^{-1}$ BAP, respectively, which were higher frequencies than those in NAA with Kinetin or 2-iP. In results, 5 $mg{\cdot}L^{-1}$ 2,4-D and 3 $mg{\cdot}L^{-1}$ NAA combined with 5 $mg{\cdot}L^{-1}$ BAP were efficient for embryogenic callus induction and regeneration of Miscanthus. This system would be useful for mass-propagation and developing new cultivars via tissue culture of Miscanthus sinensis.