• Proceedings of the Plant Resources Society of Korea Conference
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• 2005.11a
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• pp.154-154
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.05a
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• pp.88-89
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• 1991

• Proceedings of the Korean Society of Crop Science Conference
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• 1996.10a
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• pp.76-77
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• 1996

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.10a
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• pp.152-157
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• 2003

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.152-158
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• 2013

Dandelion (Taraxacum officinale) is a member of family Asteraceae that grows all over the Korea. Recently, dandelion was cultivated for medicinal crops because of its positive medicinal effects. However, dandelion is considered as a troublesome weed in grass lawns of golf course and orchards. This study was conducted to investigate the effect of plant growth regulators [gibberellins ($GA_3$); kinetin; salicylic acid (SA); ethephon)] with different concentration on seed germination control of dandelion. Seed germination rates were increased in all concentration of $GA_3$ and kinetin treatment compared to control. In the 0.5 mM of ethephon application, seed germination rate was more increased than that of control while seed germination rate was reduced in 1.0 and 1.5 mM of ethephon treatments. Seed germination rate was significantly decreased with different SA dilutions compared to control. The germination rate was more reduced when SA was applied in combination with $GA_3$ than only SA treatments.

• FLOWER RESEARCH JOURNAL
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• v.17 no.4
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• pp.303-307
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• 2009

The purpose of this study was to investigate the effects of ethephon, paclobutrazol, and uniconazole on the flowering of potted Yarrow (Archillea millefolium). Each plant growth regulator was sprayed two times before stem elongation period of yarrow. The tallest was 45.7 cm at $1000mg{\cdot}L^{-1}$ ethephon and the shortest was 11.1 cm at 20 uniconazole. Uniconazole delayed flowering and decreased the number of flowers. Both uniconazole at 20 ppm and paclobutrazol at 200 ppm decreased the number of florets to 90.0% and 43.6% of control, respectively. In ethephon, number of florets was increased 34.1% compared with control. In addition, ethephon and paclobutrazol increased the number of mean auxillaly flowers to 28.6% and 23.5% of control, respectively. On the other hand, uniconazole decrease the number of auxillary flowers to 55.3%. Thus, paclobutrazol was recommended as a suitable plant growth regulator for yarrow pot plant production.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.8-8
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• 2019

The stringent response (SR) is characterized as a bacterial defense mechanism in response to various growth-inhibiting stresses. It is activated by accumulation of a small nucleotide regulator, (p)ppGpp, and induces global changes in bacterial transcription and translation. Recent work from our group has shown that (p)ppGpp plays a critical role in virulence and survival in Vibrio cholerae. The genes, relA and relV, are involved in the production of (p)ppGpp, while the spoT gene encodes an enzyme that hydrolyzes it in V. cholerae. A mutant strain defective in (p)ppGpp production (i.e. ${\Delta}relA{\Delta}relV{\Delta}spoT$ mutant) lost the ability to produce cholera toxin (CT) and lost their viability due to uncontrolled production of organic acids, when grown with extra glucose. In contrast, the ${\Delta}relA{\Delta}spoT$ mutant, a (p)ppGpp overproducer strain, produced enhanced level of CT and exhibited better growth in glucose supplemented media via glucose metabolic switch from organic fermentation to acetoin, a neutral fermentation end product, fermentation. These findings indicates that (p)ppGpp, in addition to its well-known role as a SR mediator, positively regulates CT production and maintenance of growth fitness in V. cholerae. This implicates SR as a promising drug target, inhibition of which may possibly downregulate V. cholerae virulence and survival fitness. Therefore, we screened a chemical library and identified a compound that induces medium acidification (termed iMAC) and thereby loss of wild type V. cholerae viability under glucose-rich conditions. Further, we present a potential mechanism by which the compound inhibits (p)ppGpp accumulation. Together, these results indicate that iMAC treatment causes V. cholerae cells to produce significantly less (p)ppGpp, an important regulator of the bacterial virulence and survival response, and further suggesting that it has a therapeutic potential to be developed as a novel antibacterial agent against cholera.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.137-141
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• 2009

This experiment was investigated to effect of divided rhizome size and medium type on survival rate and growth of wasabi for 60 days in controlled growth room. In divided rhizome size of 5mm above, survival rate was 100% and their growth (plant height of 12cm and leaf number of 3${\sim}$4 per plant) was good at 30 days after wrapped-sphagnum treatment. Plant height was 20cm above and number of leaves increased in 1-2 per plant at 60 days after treatment. Survival rate and growth didn't show any effect on plant regulator of root-tone. In inorganic media (saprolite and aerated light stone) treatment, survival rate of wasabi in divided size of 5${\sim}$10mm showed 83% or above at 30 days in deep flow culture. Growth did not show significant difference of inorganic support media treatments. Therefore, it is possible for divided rhizome size of 5mm above to do production of seedlings by acclimatize for 30 days in hydroponics under controlled growth chamber.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.21-25
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• 2006

Phragmites australis (reed) has received much attention as being one of the principle emergent aquatic plants for treating industrial and civil wastewater. Plant regeneration via plant tissue culture in p. australis was investigated. Three types of callus were identified from seeds on N6 medium plus 4.5 UM 2,4-dichlorophenoxyacetic acid (2,4-D). Yellow compact type showed the best redifferentiation, whereas white compact type and yellow friable were not competent to differentiate into plane. Solid medium culture was better than liquid suspension culture for enhancing callus growth when N6 medium supplemented with 4.5 ${\mu}M$ 2,4-D was used. Phytagel, as a gelling agent, was superior to agar in plant regeneration on N6 medium, supplemented with 9.4 ${\mu}M$ kinetin and 0.54 ${\mu}M$ $\alpha$-naphthaleneacetic acid (NAA). Transfer of the plantlets regenerated from kinetin and NAA-supplemented N6 medium to growth regulator-free MS medium enhanced the further development of the plantlets. Plantlets on subsequently grown to maturity when tansferred to potting soil. The regenerated plants exhibited morphologically normal. The system for plant regeneration of P. australis enables to propagate elite lines on a large scale for water purification in the ecosystem

• The Plant Pathology Journal
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• v.30 no.2
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• pp.220-227
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• 2014

The GacS/GacA system in the root colonizer Pseudomonas chlororaphis O6 is a key regulator of many traits relevant to the biocontrol function of this bacterium. Proteomic analysis revealed 12 proteins were down-regulated in a gacS mutant of P. chlororaphis O6. These GacS-regulated proteins functioned in combating oxidative stress, cell signaling, biosynthesis of secondary metabolism, and secretion. The extent of regulation was shown by real-time RT-PCR to vary between the genes. Mutants of P. chlororaphis O6 were generated in two GacS-regulated genes, trpE, encoding a protein involved in tryptophan synthesis, and prnA, required for conversion of tryptophan to the antimicrobial compound, pyrrolitrin. Failure of the trpE mutant to induce systemic resistance in tobacco against a foliar pathogen causing soft rot, Pectobacterium carotovorum SCCI, correlated with reduced colonization of root surfaces implying an inadequate supply of tryptophan to support growth. Although colonization was not affected by mutation in the prnA gene, induction of systemic resistance was reduced, suggesting that pyrrolnitrin was an activator of plant resistance as well as an antifungal agent. Study of mutants in the other GacS-regulated proteins will indicate further the features required for biocontrol-activity in this rhizobacterium.