• Plant Biotechnology Reports
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• v.4 no.2
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• pp.109-116
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• 2010

Morinda citrifolia adventitious roots were cultured in shake flasks using Murashige and Skoog medium with different types and concentrations of auxin and cytokinin. Root (fresh weight and dry weight) accumulation was enhanced at 5 $mg\;l^{-1}$ indole butyric acid (IBA) and at 7 and 9 $mg\;l^{-1}$ naphthalene acetic acid (NAA). On the other hand, 9 $mg\;l^{-1}$ NAA decreased the anthraquinone, phenolic and flavonoid contents more severely than 9 $mg\;l^{-1}$ IBA. When adventitious roots were treated with kinetin (0.1, 0.3 and 0.5 $mg\;l^{-1}$) and thidiazuron (TDZ; 0.1, 0.3 and 0.5 $mg\;l^{-1}$) in combination with 5 $mg\;l^{-1}$ IBA, fresh weight and dry weight decreased but secondary metabolite content increased. The secondary metabolite content (including 1,1-diphenyl-2-picrylhydrazyl activity) increased more in TDZ-treated than in kinetin-treated roots. Antioxidative enzymes such as catalase (CAT) and guaiacol peroxidase (G-POD), which play important roles in plant defense, also increased. A strong decrease in ascorbate peroxidase activity resulted in a high accumulation of hydrogen peroxide. This indicates that adventitious roots can grow under stress conditions with induced CAT and G-POD activities and higher accumulations of secondary metabolites. These results suggest that 5 $mg\;l^{-1}$ IBA supplementation is useful for growth and secondary metabolite production in adventitious roots of M. citrifolia.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.51-59
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• 2008

Lettuce, a typical light-induced seed germination type, exhibits different germination responses according to cultivars, light quality, and plant growth regulator (PGR) treatments. Germination rates in most tested cultivars were over 85% under both white and red light, and were slightly decreased by blue light. Although photo-inhibition in germination was observed from most cultivars by far-red light, 'Cheongguangcheongchima', 'Okdol', and 'Manchudaecheongchima' could be classified as photo-insensitive lettuce cultivars by exhibiting the germination rates as 78,63, and 48% under for-red light, respectively. 6-Benzylamino purine (BAP) and kinetin promoted seed germination and normal seedling production under far-red light, but ethephon did not show any positive effects. Cytokinins such as BAP, kinetin, thidiazuron (TDZ), and zeatin overcame photo-inhibition of seed germination even the concentration of below $50\;mg{\cdot}L^{-1}$. However, auxins such as IBA, 2,4-D, and NAA failed to overcome the far-red light-induced photo-inhibition.

• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.57-61
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• 2005

The influence of different growth regulators on biomass of adventitious roots and secondary metabolites accumulation in bioreactor cultures of Eleutherococcus koreanum was studied. The maximum growth of adventitious roots was observed in the presence of $2.0\;\cal{mg/L}$ IBA (6.7 g DW/L). However the productivity of eleutheroside E was not significantly different among IBA levels. High level of thidiazuron (TDZ) efficiently increased both root growth and secondary metabolites production. Especially when $0.1\;\cal{mg/L}$ TDZ was combined with $3.0\;\cal{mg/L}$ IBA, the highest eleutheroside E accumulation ($3,327{\mu}g/g $DW) was observed. When the same TDZ level was treated in combination with $5.0\;\cal{mg/L}$ IBA, both chlorogrnic acid and eleutheroside B were accumulated to maximum level. In contrast, zeatin remarkably suppressed the accumulation of both eleutheroside B and chlorogenic acid.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.37-41
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• 2004

In vitro culture system was established to induce multiple shoots of Thymus quinquecostatus Celak. by investigating the effects of cytokinins. Stem explants were cultures on MS medium supplemented with either five drfferent plant growth regulators or their combinations under light or dark condition. The most effective cytokininsource was the combination of BA 1.0mg/L and TDZ 0.1mg/L for producing shoots (6.05$\pm$1.51), zeatin 2.0mg/L and TEZ 0.1mg/L for elongating shoots (3.27$\pm$0.66cm) under the light condition. In addition the most effective cytokinin was 2-ip 2.0mg/L for producing shoots(5.20$\pm$1.81), zeatin 2.0mg/L for elongating shoots(5.64$\pm$1.24cm)under the dark condition. Overall, the average percent for in vitro shooting was greater than 89.58％.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.115-121
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• 2003

In this study, plant regeneration and Agrobacterium tumefaciens-mediated transformation Kentucky bluegrass(Poa pratensis L.) were evaluated. Three different types of calli were produced depending on the combinations of growth regulators. They were non-friable brown or gray-colored callus (type I), compact, friable and yellow or white-colored callus (typeII), and soft, watery translucent callus with differentiated structure (typeIII). The highest regenerable organogenic callus (typeII) was obtained on the medium containing 1mg/L, 2,4-D and 0.1mg/L BA. Additionally, the production of typeII calli increased significantly when AgNO$_3$ was added to the callus induction and growth medium. The highest frequency of multiple shout formation from typeII callus was obtained on MS medium containing 1mg/L BA and 1mg/L Thidiazuron(TDZ). The organogenic calli(typeII) were inoculated with Agrobacterium tumefaciens strain EHA101 harboring the binary vector pIG121Hm with $\beta$-glucuronidase gene, and various factors were found to influence the transfer-DNA delivery efficiency. The highest transient GUS activity was observed on typeIIcallus. In the present work, we reported the first transient GUS activity of Kentucky bluegrass mediated by Agrobacterium tumefaciens. Our system may contribute to genetic improvement for breed-recalcirtrant grass species, Kentucky bluegrass.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.235-238
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• 2015

Adventitious buds were obtained from isolated cotyledons cultured on MS medium with various concentrations of 6-benzylamino purine (BA) and thidiazuron (TDZ). The highest numbers of adventitious buds were obtained on MS medium supplemented with 0.2 mg/L BA. Experimental culturing with half the petiole portion and half with the terminal segments were grown on MS medium contained with 0.2 mg/L BA. Frequency of the adventitious bud induction was variable accordingly to the type of cultured explants. Explants with the half petiole showed the highest adventitious bud induction rate (80%) compared to explants of half with terminal segment (20%). An elongated shoot from the buds and growth of advent roots were both possible on the 1/2 MS medium without a plant growth regulator. These results offer an effective way in which clonal propagation can be accomplished.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.174-178
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• 2009

Presently, we report a simple, reproducible and high frequency plant regeneration in Hibiscus syriacus L. using axillary buds. H. syriacus was regenerated from axillary buds directly or through a callus phase. Regenerated shoots were directly induced from young and fresh axillary buds cultured on Murashige and Skoog medium (MS) supplemented with 0.01 mg/L of the growth regulator thidiazuron (TDZ) after 2 weeks of culture. Directly induced shoots were transferred to hormone-free MS medium and root development was observed after 6 weeks. On the other hand, old and stale axillary buds were regenerated to shoots via callus induction on MS medium containing 0.01–2 mg/L TDZ after 4 weeks. A TDZ concentration of 0.01 mg/L was most effective in callus formation. Green callus was transferred to MS medium containing 0.01 mg/L α-naphthalene acetic acid (NAA) and 0.5 mg/L benzylaminopurine (BA). After 4 weeks, callus had developed into multiple shoots. Plantlets were formed from 10 week cultures of single shoots on hormone-free MS medium. Regenerated plantlets were cultured on MS medium for one month and then transferred to pots containing garden soil. Potted plants were acclimatized for one month and grown to maturity under greenhouse conditions. The present study has shown that various concentrations of plant growth regulator can be effective for in vitro plant regeneration of H. syriacus. The direct and indirect regeneration protocol presented here will be useful for understanding the manipulation and propagation of H. syriacus.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.252-264
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• 2017

Tea is one of the most consumed beverages worldwide and the relatively high levels polyphenols is benefit for health. In this study, we developed an efficient system for proliferation of callus from 'Anji Baicha', a cultivar of tea (Camellia sinensis). Callus tissue was initially induced by culturing leaf explants on medium containing different plant growth regulators. For callus induction, thidiazuron (TDZ) was more effective than 2,4-dichlorophenoxyacetic acid (2,4-D), ${\alpha}-naphthalene$ acetic acid (NAA), and $N^6-benzyladenine$ (BA). The frequency of callus induction from leaf explants reached 90.21% on $1.0mg{\cdot}L^{-1}$ TDZ and the developed callus was reddish and friable. We also tested the effect of different concentrations of NAA, 2,4-D, indole 3-acetic acid (IAA), BA, and TDZ, alone and in combinations, on callus proliferation. Medium supplemented with TDZ in combination with IAA was suitable for callus proliferation and accumulation of tea polyphenols. The growth index value and tea polyphenol content of callus cultured on MS medium containing $0.5mg{\cdot}L^{-1}$ TDZ and $1.0mg{\cdot}L^{-1}$ IAA was maximally 1,351% and 23.24%, respectively, and the relative abundance of epicatechin was as high as 17.449%. We also measured the antioxidant activity of all samples and the callus with the highest tea polyphenol content also exhibited high potential radical scavenging activity.

• Journal of Plant Biotechnology
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• v.3 no.2
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• pp.89-94
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• 2001

In vitro plant regeneration of inbred breeding line of hot pepper (Capsicum annuum L.) was established using leaf and petiole segments as explants. About 28 days old plants were excised and cultured on MS medium supplemented with TDZ and NAA or in combination with Zeatin. In all of the media compositions tested, combination of TDZ 0.5 mg/L, Zeatin 0.5 mg/L, and NAA 0.1 mg/L was found to be the best medium for shoot bud initiation. Young petiole was the most appropriate explant type for the plant regeneration as well as genetic transformation in hot pepper. In this study, HpMADS1 gene isolated from hot pepper was introduced using Agrobacterium-mediated transformation system. Based on the analysis of Southern blot and RT-PCR, HpMADS1 gene was integrated in the hot pepper genome. It has been known that floral organ development is controlled by a group of regulatory factors containing the MADS domain. Morphological characteristics in these transgenic plants, especially flowering habit, however, were not significantly altered, indicating this MADS gene, HpMADS1 may be non-functional in this case.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.167-171
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• 1994

This study was carried out to investigate the possibility of plant regeneration through somatic embryogenesis in suspension culture of Aralia elata S. Callus was induced from the explants of leaf and petiole cultured in the MS media containing 2,4-D and TDZ. More embryogenic calli were formed from petiole and with combination treatment of 24-D and TDZ. The quarter strength MS medium was effective for increasing number of somatic embryos. Mannitol supplemented to the quarter strength MS medium, reduced somatic embryo formation but inositol increased. Normal plantlets(86%) were regenerated from mature somatic embryos in MS basal medium and 50% of those survied when transplanted to the vermiculite in greenhouse.