• Animal cells and systems
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• v.13 no.3
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• pp.289-295
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• 2009

Cyclic AMP-mediated signaling pathways regulate a number of cellular functions. In this study, we examined the regulatory role of cAMP signaling pathways in chondrogenesis of chick limb bud mesenchymal cells in vitro. Forskolin, which increases cellular cAMP levels by the activation of adenylate cyclase, enhanced chondrogenic differentiation. Inhibition of PKA with specific inhibitors (H89 or KT5720) blocked pre-cartilage condensation stage, indicating that chondrogenesis is regulated by the increase in cellular cAMP level and subsequent activation of PKA. Downstream signaling pathway of PKA leading to gene expression was investigated by examination of several nuclear transcription factors. Forskolin treatment increased transcription level for a cartilage-specific marker gene Sox9. However, inhibition of PKA with H89 led to restore expression of Sox9, indicating PKA activity was required to regulate the expression of Sox9 in chondrogenesis. In addition, CREB was highly phosphorylated at early stage of mesenchyme culture, and followed by progressive dephosphorylation. CBP and ATF, another CRE related proteins were transiently expressed at the early stage of chondrogenesis with a pattern similar to CREB phosphorylation. Electrophoretic mobility shift assays confirmed that the binding activity of CREB to the CRE is closely correlated to the phosphorylation pattern of CREB. Therefore, cAMP-mediated signal transduction to nuclear events for the induction of genes appeared to be required at the early stage of chick limb bud chondrogenesis.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.227-231
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• 1994

The experiments were conducted to obtain culture conditions on optimal cultural conditions for propagation of a topical orchid, Haemaria discolor, through shoot tip cultrue in vitro. Survival percentage of shoot tip explant, in initial culture media was higher in H$_3$P$_4$ medium than in Murashige and Skoog's medium. Explants, cultured in H$_3$P$_4$ medium containing 1.0 mg/L kinetin, showed more shoot elongation when compared with those on other media. When the distal part of stem (pseudobulb) was longitudinally sectioned into half and cultured in H3P4 medium containing 0.1 mg/L 2ip, 0.1, or 1.0 mg/L kinetin, shoots from axillary bud were much more elongated under light condition.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.392-396
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• 2009

Protocorms were newly formed from the culture of axillary buds, obtained in the seedlings of Dendrobium moniliforme in vitro. Its formation ratio was calculated to 43.7% on MS medium containing 1.0 mg/L BA. To test their survival ratio, we gradually increased the inoculation of transplant populations from single to more than three, and then found that the ratio in three populations went up as high as 95.2% rather than those of one or two. In bioreactor, explant obtained from the axillary bud grew well in lower concentration as 1/4 MS medium, while clearly grew slow in a little bit high concentration as 1/2 MS medium. We found that the explant of axillary bud, obtained from the Dendrobium moniliforme seedlings, would grow five times after culturing in a bioreactor for six weeks in 1/4 MS medium.

• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.53-62
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• 2019

The purpose of this study was to establish the in vitro propagation system by shoot tip culture of six Hosta species native to Korea (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) for mass proliferation and a new cultivar development. The shoot tips of each Hosta species were cultured on MS medium containing eight combinations of 0.5, 1.0, 2.0, 4.0 mg/L BA with 0.1 mg/L NAA, 0.1, 0.5, 1.0, 2.0 mg/L TDZ with 0.1 mg/L NAA, and without any PGRs (control). They were investigated on callus, somatic embryo, crown bud, differentiation and growth of shoot and root, total fresh weight after 8 weeks of culture. In all six Hosta species, callus and somatic embryo induction rate and multiple shooting rate of the PGRs treatment group were higher than that of the control group. The highest number of differentiated shoots were obtained on medium supplemented with 2.0 ㎎/L TDZ in H. capitata (5.4), 1.0 mg/L TDZ in H. clausa and H. jonesii (3.3 and 5.8, respectively), 0.5 mg/L BA in H. minor (11.1), 1.0 mg/L BA and 0.1 mg/L TDZ in H. venusta (8.1), and 0.5 mg/L TDZ in H. yingeri (9.8). In somatic embryo formation, the PGRs treatment group of H. jonesii and H. yingeri were more effective than the control group, and the effects were relatively less in H. capitata, H. clausa Nakai, H. minor, H. venusta. Crown bud formation of four Hosta species (H.capitata, H. clausa, H. jonesiig, and H. yingeri) were also higher in the PGRs treatment group than in the control group. Crown bud formation of four Hosta species (H.capitata, H. clausa, H. jonesiig, and H. yingeri) were also higher in the PGRs treatment group than in the control group. H. clausa showed no significant effect on callus and shoot differentiation regardless of the type and concentration of cytokinin, but slightly increased in formation of crown bud in TDZ.

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.153-154
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• 2010

• Proceedings of the Plant Resources Society of Korea Conference
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• 2005.11a
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• pp.75-75
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• 2005

• Journal of Forest and Environmental Science
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• v.37 no.2
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• pp.148-153
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• 2021

This study was carried out to establish in vitro propagation system influenced by plant growth regulators through organogenesis with three different seed sources (China, Mongolia and Russia) for conservation of genetic resources in Northeast Asia. The experiment compared two different carbon sources (commercial sugar, sucrose), which showed no significant differences in germination rate. Induced adventitious buds from leaf segments were found to be highly effective when supplemented with 1.0 mg/L BA, 1.0 mg/L Kinetin, and 5.0 mg/L IAA, in the case of Chinese origin 96.8%, Russian origin R-1: 95.6%, R-2: 85.6%, and Mongolian origin M-2: 77.8%. It was effective in BA and Kinetin with supplemented with IAA, respectively. Shooting development was also efficient in Woody Plant Media (WPM) supplemented with 1.0 mg/L BA, 1.0 mg/L Kinetin and 5.0 mg/L IAA.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.300-303
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• 2005

A propagation for Fatsia japonica using axillary bud explants were established. Cultures were initiated from axillary bud explants on MS medium supplemented with IAA $(1,2,3\;mgl^{-1})$, 2,4-D $(1,2,3\;mgl^{-1})$ or NAA $(1,2,3\;mgl^{-1})$ in combination with BA $(0.5\;mgl^{-1})$. The maximum shoot bud formation was obtained in MS medium supplemented with $0.5\;mgl^{-1}$ BA and $2;mgl^{-1}$ IAA after 4 weeks culture. The microshoot rooted within 4 week in MS medium containing $1.0\;mgl^{-1}$ IBA.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.568-572
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• 2010

In order to develop an efficient micropropagation system for a rare tree species, Empetrum nigrum var. japonicum K. Koch, the effect of medium salt, cytokinins and auxin at different concentration were evaluated. Shoot induction from axillary bud was better on WPM medium than on MS medium. Although there was no significant differences observed in shoot induction among the salt strengths of WPM medium, whereas healthy shoots were developed on basal WPM medium. In comparison of the cytokinins affecting shoot proliferation, zeatin was better than BA, whereas BA exhibited more effectiveness on shoot elongation. In vitro root formation was better on WPM medium than on 1/2MS medium and achieved the highest rooting rate when 5.0 mg/L IBA treatment. 93% of rooted plantlets were survived on artificial soil mixture after 4 weeks of acclimatization. Above results suggest that a rare tree species, E. nigrum var. japonicum can be micropropagated via axillary bud cultures.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.694-701
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• 2014

Allium hookeri L. (Alliaceae family) is an important ethnomedicinal plant native to the Himalayan region of Asia. The aim of this research was to establish a high-frequency plant regeneration system for in vitro propagation of A. hookeri. Among the tissue types examined, receptacle explants derived from immature flower buds showed the highest regeneration rate of shoots ($93.33{\pm}4.63%$), roots ($76.67{\pm}7.85%$), and calli ($80.00{\pm}7.43%$) when cultured on Gamborg B5 (B5) medium containing $10{\mu}M$ 6-benzylaminopurine (BA) + $1{\mu}M$ naphthalene acetic acid (NAA), $0.5{\mu}M$ BA + $5{\mu}M$ NAA, and $1{\mu}M$ BA + $10{\mu}M$ NAA, respectively. Shoot multiplication was superior when cultured in liquid rather than on solid medium and relatively high concentrations of BA, ranging from 5 to $10{\mu}M$. Efficient bulblet formation following root induction from shoot clumps was achieved with culture in liquid B5 medium containing 7% (w/v) sucrose. Regenerated bulblets were successfully acclimatized to ex vitro conditions with a greater than 95% survival rate. By this method, a maximum of 62 plantlets per receptacle could be propagated within 9 weeks of initial culture. The in vitro propagation system established in this study will promote A. hookeri biotechnology, including large-scale production of healthy and aseptic clones, preserving parental genotypes with desirable traits, and genetic manipulation to enhance medicinal value.