• Molecules and Cells
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• v.41 no.4
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• pp.311-319
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• 2018

The gaseous hormone ethylene influences many aspects of plant growth, development, and responses to a variety of stresses. The biosynthesis of ethylene is tightly regulated by various internal and external stimuli, and the primary target of the regulation is the enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS), which catalyzes the rate-limiting step of ethylene biosynthesis. We have previously demonstrated that the regulation of ethylene biosynthesis is a common feature of most of the phytohormones in etiolated Arabidopsis seedlings via the modulation of the protein stability of ACS. Here, we show that various phytohormones also regulate ethylene biosynthesis from etiolated rice seedlings in a similar manner to those in Arabidopsis. Cytokinin, brassinosteroids, and gibberellic acid increase ethylene biosynthesis without changing the transcript levels of neither OsACS nor ACC oxidases (OsACO), a family of enzymes catalyzing the final step of the ethylene biosynthetic pathway. Likewise, salicylic acid and abscisic acid do not alter the gene expression of OsACS, but both hormones downregulate the transcript levels of a subset of ACO genes, resulting in a decrease in ethylene biosynthesis. In addition, we show that the treatment of the phytohormones results in distinct etiolated seedling phenotypes, some of which resemble ethylene-responsive phenotypes, while others display ethylene-independent morphologies, indicating a complicated hormone crosstalk in rice. Together, our study brings a new insight into crosstalk between ethylene biosynthesis and other phytohormones, and provides evidence that rice ethylene biosynthesis could be regulated by the post-transcriptional regulation of ACS proteins.

• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.53-55
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• 1997

The shoot tips of Delphinium cv. Princess Caroline were cultured on the MS medium supplemented with cytokinin and auxin alone or in combination. Among cytokinins, BA was most effective in shoot multiplication, adequqte concentrations being 1.0-5.0 mg/L. Shoot multiplication was very favorable on the media with 1.0-3.0 mg/L BA and 0.1-0.5 mg/L IAA. Additions of BA and IAA did not stimulate shoot multiplication, but increased a little fresh weight. Shoots were scarcely rooted on the media with IBA or NAA, and were not done utterly on the media containing activated charcoal. Therefore, shoots were treated by Rootone and planted in the cultural media for in vivo rooting. The highest rate of rooting was 68% in the mixed cultural medium composed of Perlite 1 and Vermiculite 1.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.21-27
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• 2011

This study was carried out to produce multiple shoots and bulblets from flower stalk tissue cultures of Muscari armeniacum LEICHTLIN ex BAKER 'Early Giant', which were cultured in the half strength Murashige & Skoog's (MS) medium supplemented with auxin, NAA in combination with kinetin, BA, and TDZ, alone and/or. In flower stalk tissue culture, upper part explant was the most suitable as a source of culture material. Direct shoot formation was much more favorable in half strength MS medium supplemented with $0.1mg{\cdot}L^{-1}$ NAA and $1.0mg{\cdot}L^{-1}$ TDZ. On the other hand, bulblet formation was increased when cultured in half strength MS medium added with $0.01mg{\cdot}L^{-1}$ NAA and $0.1mg{\cdot}L^{-1}$, $0.2mg{\cdot}L^{-1}$ kinetin. Acclimatized plant flowered during the second year of the growing period without any phenotypic variations and formed average 1.5 bulblets per mother bulb.

• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.73-81
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• 2007

An efficient regeneration system was developed using leaf, petiole, and internode explants. Highly embryogenic callus was obtained following cultivation on MS basal nutrient supplemented with 2 $mg/{\ell}$ 2,4-D. Globular, heart, torpedo and cotyledon shaped somatic embryo were produced from the surface of embryogenic callus. Direct shoot regeneration without intermediate callus formation has been achieved on MS medium supplemented NAA and BAP. The percentage of response varies with different concentration of auxin and cytokinin treated individually or in combination. The best shoot regeneration response (54.28%) and number of shoot per explant (12.67) were achieved on the medium supplemented with 0.1 $mg/{\ell}$ NAA and 1 $mg/{\ell}$ BAP. The regenerated shoot transformed into young plant when cultured into elongation and root induction medium. More than 90% of in vitro propagated plants could survive when transferred to the greenhouse for acclimation. This optimized regeneration system can be used for rapid shoot proliferation and genetic transformation.

• BMB Reports
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• v.32 no.1
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• pp.51-59
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• 1999

The Korean radish cationic peroxidase (KRCP) promoter, comprising nucleotides -471 to +704 relative to the transcriptional initiation site, was fused to the GUS gene and transformed to tobacco BY-2 cells. We examined how auxin (2,4-dichlorophenoxyacetic acid, 2,4-D), cytokinin (6-benzylaminopurine, BAP), gibberellic acid ($GA_3$), abscisic acid (ABA), methyl jasmonate (MeJA), and phosphatidic acid (PA) affect the GUS expression in the presence or absence of 2,4-D in a modified LS medium. Exogenous 2,4-D or BAP greatly decreased the GUS expression regulated by the KRCP promoter in a modified LS medium containing 0.2 mg/l 2,4-D. $GA_3$ increased the GUS expression and ABA completely reduced the inductive effect of $GA_3$. The GUS expression was also increased dose-dependently by plant defense regulators, MeJA and PA. In contrast to the above results, auxin deprivation from the modified LS medium increased the GUS expression after treatment with exogenous 2,4-D whereas BAP still greatly decreased the GUS expression dose-dependently. $GA_3$ or MeJA slightly decreased the GUS expression. The data suggest that auxin deprivation changes the sensitivity of the suspension cells to exogenous chemicals and that the regulation of the KRCP promoter by 2,4-D, $GA_3$, and MeJA is dependent on auxin, whereas the regulation by BAP is not. This study will be valuable for understanding the function and expression mode of the Korean radish cationic peroxidase in Korean radish.

• Journal of Haehwa Medicine
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• v.22 no.2
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• pp.67-79
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• 2014

In order to investigate the efficacy of BJBB on atopic dermatitis, various immune related factors were studied. The results and conclusions are as follows. Atopic dermatitis symptoms were improved in BJBB treated group and significant decrease in dermatitis index were observed in 13 weeks. ALT, AST and BUN, Cr levels were all with in the normal ranges in BJBB treated group, indicating no induced toxicity. BJBB treated group showed significant decrease in CD4+, CD11b+/Gr-1+ immune cell ratio in dorsal skin by 33% and 62% respectively. BJBB treated group showed significant decrease in the expression of IL-4, IL-5, IL-13 and histamine by 83%, 62%, 53% and 61% respectively. Also the group showed decrease in the transcription of IL-4, IL-5 and IL-13 mRNA in spleen by 41%, 52% and 50% respectively. BJBB treated group showed decrease in the expression of IgE by 57% respectively. The results above indicated that treatment of BJBB improved atopic dermatitis symptoms by immune modulation activity a clinical evidence. thus, BJBB has a potential use as a composition of medicinal plants for treatment against inflammation related disease.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.403-409
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• 2005

Mature nodal segments of 2-year-old greenhouse stock plant were cultured on Murashige and Skoog basal medium supplemented with the different kinds and various concentrations of cytokinins to produce multiple shoots in in vitro condition. The most adventitious shoots were produced from excised ends of nodal segments. The highest average number $(24.6\;{\pm}\;4.6)$ of shoots was produced with the combination of BA 1.0mg/L and TDZ 0.1mg/L in MS medium. In addition, several shoots were formed from lenticels of bark cambium with the same treatment. These concentrations promoted high shooting capability upto $94.6\%$ and NAA was the best cytokinin among five different PGR sources.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.131-135
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• 1994

This experiment was designed to improve the in vitro production system of apple rootstock M.26 as being influenced by the growth regulators, TDZ, BA, IAA, IBA, zeatin, and GA$_3$. Different levels of potassium humate (KH), known as cytokinin and auxin-like substance, were also supplemented to the MS basal medium along with IBA 0.6 mg/L to find out it effect on root formation in apple rootstock M.26. ID initiate and establish the in vitro multiplication of shoots byway of meristem culture, MS medium added with zeatin 1.0 mg/L was found to be the most suitable, showing the 100% of survival rate of shoot tips. A combination of thidiazuron (TDZ) 0.2 mg/L and NAA 0.5 mg/L promoted the shoot proliferation when shoot tips were used as explants. MS basal medium plus IBA 0.6 mg/L was very effective for root induction, but an addition of potassium humate (250 mg/L) to the medium containing IBA 0.6 mg/L stimulated the induction and proliferation of the rook by far the better.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.469-474
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• 2000

Effect of the antibiotic carbenicillin on callus and shoot formation from the leaf disc culture of tobacco (Nicotiana tabacum L. cv. BY-4) was examined. The number of shoot induced from the leaf explants was decreased as the amount of carbenicillin increased from 250 mg/L to 2,000 mg/L on MS medium containing 0.5 mg/L of BAP or kinetin. In addition, calli formation from the leaf explants was increased by the treatment of 250 mg/L ∼ 500 mg/L carbenicillin with or without 0.5 mg/L of 2,4-D or NAA. However, the fresh weight of 4-week-cultured explants was decreased with increasing carbenicillin from 250 mg/L to 2,000 mg/L on MS medium containing 0.5 mg/L of 2,4-D or NAA. These results indicate that carbenicillin has an auxin-like effect, such as promoting callus formation and inhibiting shoot induction. It leads to the conclusion that the auxin-like property should be taken into account for the production of transgenic plants via Agrobacterium-mediated transformation.

• Journal of Plant Biotechnology
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• v.34 no.2
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• pp.161-166
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• 2007

In vitro shoot regeneration and multiple shoot induction has been obtained from the stolen node explants in Eremochloa ophiuroides (Munro) Hack. The highest number of shoots ($10.66{\pm}0.21$) was observed from initial explants after one month culture duration on Murashige and Skoog (MS) medium containing 6-benzyladenine (BA: 0.5 mg/l). First generation shoot was excised and sub-cultured on the same fresh media for further multiplication of shoots. An enhanced number of second round shoots ($15.33{\pm}0.21$) was obtained compared to the initial culture media containing BA (0.5 mg/l). The number of shoots/stolon node was higher among all the concentrations of BA than kinetin (KN). In vitro regenerated shoots were successfully rooted in the phytohormone free MS medium. Plantlets generated with roots were transferred to pots containing compound mixture of soil and kept in green house conditions. Acclimatized plants showed 100% survival rate with normal morphology in green house conditions. The present study demonstrates the effect of explant and different plant growth regulators towards in vitro response in E. ophiuroides. Moreover, the study reveals the effect of cytokinin on induction of shoot number per stolen node explant in E. ophiuroides.