• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.255-261
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• 2018

Aglycon protopanaxatriol (APPT) has valuable pharmacological effects such as memory enhancement and tumor inhibition. ${\beta}$-Glycosidase from the hyperthermophilic bacterium Dictyoglomus turgidum (DT-bgl) hydrolyzes the glucose residues linked to APPT, but not other glycoside residues. ${\beta}$-Glycosidase from the hyperthermophilic bacterium Pyrococcus furiosus (PF-bgl) hydrolyzes the outer sugar at C-6 but not the inner glucose at C-6 or the glucose at C-20. Thus, the combined use of DT-bgl and PF-bgl is expected to increase the biotransformation of PPT-type ginsenosides to APPT. We optimized the ratio of PF-bgl to DT-bgl, the concentrations of substrate and enzyme, and the reaction time to increase the biotransformation of ginsenoside Re and PPT-type ginsenosides in Panax ginseng leaf extract to APPT. DT-bgl combined with PF-bgl converted 1.0 mg/ml PPT-type ginsenosides in ginseng leaf extract to 0.58 mg/ml APPT without other ginsenosides, with a molar conversion of 100%. We achieved the complete biotransformation of ginsenoside Re and PPT-type ginsenosides in ginseng leaf extract to APPT by the combined use of two ${\beta}$-glycosidases, suggesting that discarded ginseng leaves can be used as a source of the valuable ginsenoside APPT. To the best of our knowledge, this is the first quantitative production of APPT using ginsenoside Re, and we report the highest concentration and productivity of APPT from ginseng extract to date.

• Journal of Ginseng Research
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• 제33권1호
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• pp.59-64
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• 2009

$Ca^{2+}$ and calmodulin (CaM), a key $Ca^{2+}$ sensor in all eukaryotes, have been implicated for defense responses of plants. Eukaryotic CaM contains four structurally and functionally similar $Ca^{2+}$ domains named I, II, III and IV. Each $Ca^{2+}$ binding loop consists of 12 amino acid residues with ligands arranged spatially to satisfy the octahedral symmetry of $Ca^{2+}$ binding. To investigate the altered gene expression and the role of CaM in ginseng plant defense system, cDNA clone containing a CaM gene, designated PgCaM was isolated and sequenced from Panax ginseng. PgCaM, which has open reading frame of 450 nucleotides predicted to encode a precursor protein of 150 amino acid residues. Its sequence shows high homologies with a number of other CaMs, with more similarity to CaM of Daucus carota (AAQ63461). The expression of PgCaM in different P. ginseng organs was analyzed using real time PCR. The results showed that PgCaM expressed at different levels in young leaves, shoots, and roots of 3-week-old P. ginseng. In addition, the expressions of PgCaM under different abiotic stresses were analyzed at different time intervals.

• 한국약용작물학회지
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• 제17권3호
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• pp.187-191
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• 2009

This study was conducted to assess the response of LED (Light-emitting diode) irradiation on the growth characteristics and saponin contents of Panax ginseng C. A. Meyer. LED irradiation showed a positive effect for most of the parameters studied. The content of chlorophyll a in leaves was increased by 4.9$\sim$36.5%, under LED and fluorescent light conditions compared to the control. The content of chlorophyll b was also increased by 44.4$\sim$55.6% under blue and red LED compared to the control except under the red plus blue LED condition. The shoot and root weight were increased by $20\sim60%$ and $14.8\sim59.3%$, respectively under LED and fluorescent light conditions compared to the control. The total saponin content was increased by 1.8% under blue LED compared to the control, while total saponin content was decreased by 8.8$\sim$11.5% under red LED, red plus blue LED and fluorescent light conditions.

• Journal of Plant Biotechnology
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• 제43권1호
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• pp.99-103
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• 2016

고려인삼은 다년생 약용작물로써 재배 특성상 인삼에서 다양한 질병들의 효과적인 방제시스템의 개발은 인삼의 생산량 증대에 매우 중요한 요소이다. 최근 지속가능한 농업의 실현을 위한 식물의 유도저항성(ISR)과 유용미생물의 항생제 효과를 이용한 친환경 생물학적 방제 기법이 주목을 받고 있다. 하지만 인삼의 유도정항성을 정확하게 판단할 수 있는 기법은 아직까지 거의 연구되어 있지 않다. 본 논문에서는 인삼의 유묘를 이용한 무병주 기내배양 시스템을 개발하였고, BTH에 의해 유도되는 인삼의 유도저항성을 통한 잿빛곰팡이병과 탄저병에 대한 방제효과를 검증하였다. 인삼유묘에 유도저항성을 위해 뿌리에 직접적으로 BTH를 처리하는 관주처리 방법에 비해, 잎에 직접적으로 살포하는 엽면시비 방법이 효과적으로 두 곰팡이성 병원균에 대한 방제효과가 높게 나타났다. BTH처리 인삼유묘에 탄저병원균을 처리하였을 때 인삼의 병원균 침입에 의해 급격히 발현이 증대되는 PgPR10과 PgCAT 유전자의 발현이 급속하게 증대되는 현상을 확인하였다. 본 연구를 통해 개발된 시스템은 향후 친환경적으로 이용될 수 있는 다양한 생물학적 방제제의 효과를 검정하고 활용하는데 매우 유용하게 이용될 수 있을 것이다.

• Journal of Ginseng Research
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• 제13권1호
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• pp.92-97
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• 1989

인삼엽을 강광(100 KLuw) 및 고온($45^{\circ}C$, 암상태)에 처리하여 효소(glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase)의 활성도를 조사한 결과 두 처리구에서 공히 감소하는 경향이었으나, 특기 강광에서 활성도가 현저히 감소하였다. 이와 같은 활성도 감소는 효소의 thermal stabilities나 coagulation 등과 같은 광에 의한 2차적인 엽온상승 효과에 따른 inactivation이 아니며, proteolytic activity 증가로 인한 효소단백질의 함량감소로 확인되었다. 인삼엽에서 proteolytic activity가 강광에 의해 급속히 증가하는 것으로 보아 정상엽(normal leaf)에 inactive 상태로 내재(compartmentation)되어 있는 proteinase가 타 식물에 비해 많은 것으로 사료된다. 또한 chlorphyll bleaching과 효소의 inactivation을 유발시킬 수 있는 superoxide radical(${O_2}^{-}$)의 광화학적 생성율이 비교식물(Solanum nigrum)보다 높게 나타나고 crude saponin이 superoxide의 생성율을 촉진하는 것으로 보아 superoxide에 의한 pigment system의 광산화율이 타 식물에 비해 높을 것으로 사료된다.

• Journal of Ginseng Research
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• 제40권4호
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• pp.409-414
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• 2016

Background: The low survival rate of in vitro regenerated Panax ginseng plantlets after transfer to soil is the main obstacle for their successful micropropagation and molecular breeding. In most cases, young plantlets converted from somatic embryos are transferred to soil. Methods: In vitro thickened taproots, which were produced after prolonged culture of ginseng plantlets, were transferred to soil. Results: Taproot thickening of plantlets occurred near hypocotyl and primary roots. Elevated concentration of sucrose in the medium stimulated the root thickening of plantlets. Senescence of shoots occurred following the prolonged culture of plantlets. Once the leaves of plantlets senesced, the buds on taproots developed a dormant tendency. Gibberellic acid treatment was required for dormancy breaking of the buds. Analysis of endogenous abscisic acid revealed that the content of abscisic acid in taproots with senescent shoots was comparatively higher than that of taproots with green shoots. Thickened taproots were transferred to soil, followed by exposure to gibberellic acid or a cold temperature of $2^{\circ}C$ for 4 mo. Cold treatment of roots at $2^{\circ}C$ for 4 mo resulted in bud sprouting in 84% of roots. Spraying of 100 mg/L gibberellic acid also induced the bud sprouting in 81% roots. Conclusion: Soil transfer of dormant taproots of P. ginseng has advantages since they do not require an acclimatization procedure, humidity control of plants, and photoautotrophic growth, and a high soil survival rate was attained.

• Journal of Ginseng Research
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• 제36권2호
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• pp.211-217
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• 2012

Endophytic fungi were isolated from various tissues (root, stem, petiole, leaf, and flower stalk) of 3- and 4-year-old ginseng plants (Panax ginseng Meyer) cultivated in Korea. The isolated endophytic fungi were identified based on the sequence analysis of the internal transcribed spacer (ITS), 1-5.8-ITS 2. A morphological characterization was also conducted using microscopic observations. According to the identification, 127 fungal isolates were assigned to 27 taxa. The genera of Phoma, Alternaria and Colletotrichum were the most frequent isolates, followed by Fusarium, Entrophospora and Xylaria. Although 19 of the 27 taxa were identified at the species level, the remainder were classified at the genus level (6 isolates), phylum level (Ascomycota, 1 isolate), and unknown fungal species (1 isolate). Endophytic fungi of 13 and 19 species were isolated from 3- and 4-year-old ginseng plants, respectively, and Phoma radicina and Fusarium solani were the most frequently isolated species colonizing the tissues of the 3- and 4-year-old ginseng plants, respectively. The colonization frequency (CF%) was dependant on the age and tissue examined: the CFs of the roots and stems in the 3-year-old ginseng were higher than the CF of tissues in the 4-year-old plants. In contrast, higher CFs were observed in the leaves and petioles of 4-year-old plants, and endophytic fungi in the flower stalks were only detected in the 4-year-old plants. In conclusion, we detected diverse endophytic fungi in ginseng plants, which were distributed differently depending on the age and tissue examined.

• Journal of Ginseng Research
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• 제37권2호
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• pp.227-247
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• 2013

MicroRNAs (miRNAs) are a class of recently discovered non-coding small RNA molecules, on average approximately 21 nucleotides in length, which underlie numerous important biological roles in gene regulation in various organisms. The miRNA database (release 18) has 18,226 miRNAs, which have been deposited from different species. Although miRNAs have been identified and validated in many plant species, no studies have been reported on discovering miRNAs in Panax ginseng Meyer, which is a traditionally known medicinal plant in oriental medicine, also known as Korean ginseng. It has triterpene ginseng saponins called ginsenosides, which are responsible for its various pharmacological activities. Predicting conserved miRNAs by homology-based analysis with available expressed sequence tag (EST) sequences can be powerful, if the species lacks whole genome sequence information. In this study by using the EST based computational approach, 69 conserved miRNAs belonging to 44 miRNA families were identified in Korean ginseng. The digital gene expression patterns of predicted conserved miRNAs were analyzed by deep sequencing using small RNA sequences of flower buds, leaves, and lateral roots. We have found that many of the identified miRNAs showed tissue specific expressions. Using the insilico method, 346 potential targets were identified for the predicted 69 conserved miRNAs by searching the ginseng EST database, and the predicted targets were mainly involved in secondary metabolic processes, responses to biotic and abiotic stress, and transcription regulator activities, as well as a variety of other metabolic processes.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.17-17
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• 2018

Panax ginseng Meyer is a perennial medicinal plant, the roots of which has been used in the traditional formulations in Oriental countries. To understand its floral transition, we isolated Flowering Locus T (FT) from ginseng, the bioinformatics analysis of PgFT has revealed a considerable homology to the higher plants, with the essential amino acids for FT function are conserved. The phylogenetic analysis has shown that the PgFT is belonged to the shrub classes of plants and closest kin to Jatropha curcas FT. The expression profiling from juvenile (2-year-old) were abundant in leaves as well as in root and was concentrated in the secondary leaflet and stem bottom in adult (4-year-old) ginseng plant tissues, moreover PgFT transcript displayed photoperiod dependent oscillation. The ectopic expression of PgFT in Arabidopsis thaliana, exhibit precocious flowering and several floral pathway integrators were up-regulated, interestingly their root length was increased in the transgenic seedlings. Therefore, we could conclude that PgFT encodes a florigen that acts as a key regulator in the flowering pathway in ginseng and hypothesize that, it might involve in the underground organ development as well. We believe our finding could provoke future studies on the physiology and development in P. ginseng.

• Journal of Ginseng Research
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• 제41권3호
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• pp.403-410
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• 2017

Background: Prenyltransferases catalyze the sequential addition of isopentenyl diphosphate units to allylic prenyl diphosphate acceptors and are classified as either trans-prenyltransferases (TPTs) or cis-prenyltransferases (CPTs). The functions of CPTs have been well characterized in bacteria, yeast, and mammals compared to plants. The characterization of CPTs also has been less studied than TPTs. In the present study, molecular cloning and functional characterization of a CPT from a medicinal plant, Panax ginseng Mayer were addressed. Methods: Gene expression patterns of PgCPT1 were analyzed by quantitative reverse transcription polymerase chain reaction. In planta transformation was generated by floral dipping using Agrobacterium tumefaciens. Yeast transformation was performed by lithium acetate and heat-shock for $rer2{\Delta}$ complementation and yeast-two-hybrid assay. Results: The ginseng genome contains at least one family of three putative CPT genes. PgCPT1 is expressed in all organs, but more predominantly in the leaves. Overexpression of PgCPT1 did not show any plant growth defect, and its protein can complement yeast mutant $rer2{\Delta}$ via possible protein-protein interaction with PgCPTL2. Conclusion: Partial complementation of the yeast dolichol biosynthesis mutant $rer2{\Delta}$ suggested that PgCPT1 is involved in dolichol biosynthesis. Direct protein interaction between PgCPT1 and a human Nogo-B receptor homolog suggests that PgCPT1 requires an accessory component for proper function.