• Journal of Plant Biology
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• v.39 no.3
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• pp.161-166
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• 1996

The hairy root cultures of Centella asiatica were established by infection leaf explants with Agrobacterium rhizogenes A4, 15834 in 1/2 Murashing and skoog liquid medium supplemented with 50 $\mu$M acetosyringone. The induced hairy roots were subjected to paper electrophoresis for the detection of opine and opine-positive clones which were considered to have been transformed. Five hairy root clones were selected according to the different bacterial strains used, growth rate and pattern. Among media tested, MS basal medium substituted phosphate concentration by 2.5mM K2HPO4 showed the highest growth rate in the dark condition.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.249-253
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• 2004

The type of air lift bioreactor affected the root growth in ginseng adventitious root cultures. Among bioreactors used in this experiment, bulb type bubble bioreactor (BU) was the best to increase root growth (41.92 g dry weight). The kLa value representing the oxygen transfer capacity from medium to explants (6.98 h$^{-1}$ ) in BU with 5 cm bubble column was higher than other bioreactors. On the other hand, cylindric tube bioreactor (CT) without bubble column resulted in minimum root growth (38.55 g dry weight) and kLa value (5.25 h$^{-1}$ ). Furthermore, the root growth (50.30 g dry weight) in BU with 10 cm bubble column more increased than 5 cm bubble column. However, the kLa value do not affected the secondary metabolite such as ginsenosides. These results show that the bubble column in air lift bioreactor increase kLa value and increased kLa value stimulate the growth of ginseng adventitious roots.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.81-85
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• 2010

The medicinal plant, Kanzo (Glycyrrhiza uralensis), mainly grows on arid lands. The root of Kanzo has been compounded about 70% of herbal medicines in Japan because it has an important medicinal element. In addition, in recent years, the expansion of desertification becomes a serious problem. The cause is chiefly man activity such as over gathering plants1). The aim of this study is to prevent desertification by cultivating Kanzo with high quality. The first step is to grow Kanzo for greening. The second step is to stably produce the root with high medicinal quality. This paper presents growth properties of cultivating Kanzo by bottom watering method, which is under constant groundwater level. The main results of this paper are as follows: (1) The lower water content of cultivating soil is, the longer the root length is, (2) Growth of Kanzo is influenced by soil types, (3) Thick primary roots grow directly and vertically in low water content. On the other hand, thin secondary roots grow curvedly and horizontally in high water content and (4) Measuring evapo-transpiration velocity is the effective method to evaluate roots' growth tendency in the field.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.7-14
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• 1999

In order to survey anthraquinone productivity from in vitro root culture, transformed hairy roots of Rumex crispus were induced from leaf segments by infection with Agrobacterium rhizogenes strain $A_4$ and compared with adventitious roots. The optimum condition of adventitious root formation from leaf segments was 5 $\mu$M NAA added to MS medium. Mannopine was detected in the extract of hairy roots by paper electrophoresis, but not in adventitious roots. Secondary root tips of both adventitious roots and hairy roots elongated without lateral root branching in hormone free MS medium, but primary root tips showed more rapid growth with extensive lateral root branching. MS basal medium was the best for growth of the adventious roots and hairy roots for anthraquinone content. Adventitious root tips and hairy root tips cultured in liquid MS medium supplemented with 0.05 $\mu$M NAA and 0.1 $\mu$M kinetin (contained 5% sucrose) showed the maximal growth and anthraquinone content. Anthraquinone content of hairy roots was increased by the culture periods, but was reduced after 25 days of culture.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.432-436
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• 2014

The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.51-55
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• 2001

This study was conducted to establish a plant cell culture system for the production of medically important secondary metabolites from Xanthium strumarium. The effects of plant growth regulators including NAA, 2,4-D, kinetin, and ABA were examined in terms of callus induction, maintenance of callus and suspension cultures. It was shown that callus was induced upon treatment with NAA while embryo was induced after treatment with 2,4-D. Callus formation was further improved by treatment with ABA and NAA. The level of callusing increased by 17-29% for the seed case, cotyledon, leaf, and hypocotyl and by 96% in the case of the root. Suspension cell lines were established using calli produced from cotyledon, hypocotyl and root and cultured at 25$\^{C}$ under light conditions. The cells grew up to 15g/L with NAA 2ppm, BA 2ppm, and ABA 1ppm treatment. Supernatants of suspension cultures of cell lines derived from coyledon and hypocotyl produced some distinctive secondary metabolites, one of which was identified as 8-epi-tomentosin, which belongs to the xanthanolides. The amounts of 8-epi-tomentosin produced by the cotyledon- and hypocotylderived cell lines were 13.4mg/L and 11.0mg/L, respectively.

• Journal of Plant Biotechnology
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• v.48 no.3
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• pp.186-192
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• 2021

The roots of Korean ginseng (Panax ginseng) have a long history of usage as a medicinal drug. Ginsenosides, a group of triterpenioid saponins in ginseng, have been reported to show important pharmacological effects. Many studies have attempted to identify the ginsenoside synthesis pathways of P. ginseng and to increase crop productivity. Recent studies have shown that exogenous gibberellin (GA) treatments promote storage root secondary growth by integration of the modulating cambium stem cell homeostasis with a secondary cell wall-related gene network. However, the dynamic regulation of ginsenoside synthesis-related genes and their contents by external signaling cues has been rarely evaluated. In this study, we confirmed that GA treatment not only enhanced the secondary growth of P. ginseng storage roots, but also significantly enriched the terpenoid biosynthesis process in RNA-seq analysis. Consistently, we also found that the expression of most genes involved in the ginsenoside synthesis pathways, including those encoding methylerythritol-4-phosphate (MEP) and mevalonate (MVA), and the saponin content in both leaves and roots was increased by exogenous GA application. These results can be used in future development of biotechnology for ginseng breeding and enhancement of saponin content.

• 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.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.230-239
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• 2012

Coconut (Cocos nucifera L) is one of the predominant plantation crops in Sri Lankan economy which is known to have existed for over thousands of years. During the past decades coconut production had been reduced by a significant quantity. The usage of poor quality planting materials is a major reason for the low coconut production. Thus much attention needs to be paid in coconut nurseries. Weed management is a critical management practice in the nursery. Though glyphosate application is becoming popular in nurseries it can affect weeds as well as coconut seedlings growth. Therefore the effects of glyphosate were evaluated by determining the growth of shoot and root of coconut seedlings. Poly bag nursery was prepared and three treatments were used. Treatments were no glyphosate and manual weeding ($T_1$), application of glyphosate 1.08 ai kg $ha^{-1}$ at 2 monthly interval ($T_2$) and application of glyphosate 1.44 ai kg $ha^{-1}$ at 2 monthly interval ($T_3$). Application of glyphosate at early stage of seedling growth had a no significant effect on growth parameters tested. However, the concentrations of glyphosate negatively affected numbers, volumes and dry weights of secondary, tertiary and quaternary roots at the latter stage of seedling growth. The leaf area and the height of seedling were significantly reduced by the highest concentration of glyphosate. Among the growth parameters tested, seedling girth and shoot dry weight were not affected by the application of glyphosate. These results revealed that the usage of glyphosate at both concentrations negatively affected root growth of coconut seedlings. Based on these results, the both concentration levels of glyphosate should be applied to coconut nurseries before sprouting the seed nuts.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1231-1240
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• 2021

Members of the genus Bacillus are known to play an important role in promoting plant growth and protecting plants against phytopathogenic microorganisms. In this study, 21 isolates of Bacillus spp. were obtained from the root micro-ecosystem of Suaeda glauca. Analysis of the 16S rRNA genes indicated that the isolates belong to the species Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus subtilis, Bacillus pumilus, Bacillus aryabhattai and Brevibacterium frigoritolerans. One of the interesting findings of this study is that the four strains B1, B5, B16 and B21 are dominant in rhizosphere soil. Based on gyrA, gyrB, and rpoB gene analyses, B1, B5, and B21 were identified as B. amyloliquefaciens and B16 was identified as B. velezensis. Estimation of antifungal activity showed that the isolate B1 had a significant inhibitory effect on Fusarium verticillioides, B5 and B16 on Colletotrichum capsici (syd.) Butl, and B21 on Rhizoctonia cerealis van der Hoeven. The four strains grew well in medium with 1-10% NaCl, a pH value of 5-8, and promoted the growth of Arabidopsis thaliana. Our results indicate that these strains may be promising agents for the biocontrol and promotion of plant growth and further study of the relevant bacteria will provide a useful reference for the development of microbial resources.