• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.75-78
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• 2014

Burdock (Arctium sp.) is known as a nutraceutical vegetable, especially in Japanese and Korean cuisine. While burdock plants are generally harvested for their tap roots, different parts of the plant are consumed as food or used as traditional medicines. This study investigated the physicochemical properties of the leaves, stems, roots, and peeled roots of the burdock plant based on their pH, soluble solid content, titratable acidity, color values, and mineral content. The pH differed significantly among the different plant parts, with the highest value in the leaves and the lowest in the stems. However, for the soluble solid content, the leaves had the lowest, while the peeled roots had the highest. The titratable acidity of the stems was significantly lower than that of the leaves, roots, and peeled roots. As regards the color values, the lightness value was highest for the stems, while the roots showed the highest redness value, followed by the peeled roots, and the leaves had the highest yellowness value. The leaves and stems contained almost three times more potassium than the roots and peeled roots. Thus, the higher content of different minerals in the leaves and stems of the burdock plant shows that these plant parts could be used as potential sources of dietary minerals.

• Plant Resources
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• v.6 no.1
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• pp.1-6
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• 2003

Ginseng(Panax ginseng C. A. Meyer) is important medicinal plant but requires 4-year cultivation for root harvest because of slow growth. In contrast, ginseng hairy roots induced by introducing Ri-plasmid of Agrobacterium rhizogenes into genomic DNA of plant cells show vigorous growth, and the hairy roots produce the same or more saponins than natural ginseng roots. Therefore, hairy roots can be used for commercial purposes. The present study was carried out to induce hairy roots with both active growth and high saponin contents. Numerous hairy roots of Panax ginseng were obtained after root disks of three-year old roots were infected with Agrobacterium rhizogenes R1000 A4T in dark condition after one month of culture. About 3 hundred lines of hairy roots were selected according as morphological characters on medium with carbenicillin. After pre-selection of fifteen lines of hairy roots with active growth, KGHR-l and KGHR-8 lines were finally selected which had characters of high content of ginsenoside-Rd and ginsenoside-Re, respectively. The optimum growth of hairy roots was achieved in the culture of 1/2 MS liquid medium in dark (22 $^{\circ}C$) under 60 rpm gyratory shaking. Hairy roots grew well in 5L Erlenmeyer flasks, lL roller drums, 10L jar-fermenters, and especially in 20L air-lift culture vessels.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.600-604
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• 1998

Methanol extracts from 53 species of oriental medicinal plants in 34 families were tested for their fungicidal activities against Pyricularia grisea, Rhizoctonia solani, Phytophthora capsici, Phytophthora infestans, Collectotrichum dematium, Botryospaeria dothidea, Fusarium oxysporum f. sp. cucumerinum, Botrytis cinerea, Puccinia recondita, and Erysiphe graminis. In in vitro study using impregnated paper disc method, the efficacy varied with both plant pathogen and plant species tested. Methanol extracts of Asarum sieboldii roots, Sinomenium acutum roots, Pinus densiflora leaves, Rheum undulatum root barks, Coptis japonica roots, and Phellodendron amurense barks showed potent fungicidal activities against the various pathogens when treated with 10 mg/disc. In a whole plant test, methanol extracts of P. densiflora leaves and roots and C. japonica roots were highly effective against a variety of plant pathogens. As a naturally occurring fungicide, P. densiflora- and C. japonica-derived materials could be useful as new fungicidal products against various plant diseases induced by plant pathogenic fungi.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.59-66
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• 2013

Colonization studies previously performed with a green-fluorescent-protein, GFP, labeled derivative of Bacillus amyloliquefaciens FZB42 revealed that the bacterium behaved different in colonizing surfaces of plant roots of different species (Fan et al., 2012). In order to extend these studies and to elucidate which genes are crucial for root colonization, we applied targeted mutant strains to Arabidopsis seedlings. The fates of root colonization in mutant strains impaired in synthesis of alternative sigma factors, non-ribosomal synthesis of lipopeptides and polyketides, biofilm formation, swarming motility, and plant growth promoting activity were analyzed by confocal laser scanning microscopy. Whilst the wild-type strain heavily colonized surfaces of root tips and lateral roots, the mutant strains were impaired in their ability to colonize root tips and most of them were unable to colonize lateral roots. Ability to colonize plant roots is not only dependent on the ability to form biofilms or swarming motility. Six mutants, deficient in abrB-, sigH-, sigD-, nrfA-, yusV and RBAM017410, but not affected in biofilm formation, displayed significantly reduced root colonization. The nrfA- and yusV-mutant strains colonized border cells and, partly, root surfaces but did not colonize root tips or lateral roots.

• Journal of Plant Biology
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• v.33 no.3
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• pp.183-188
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• 1990

Induction and culture of hairy roots by Agrobacterium rhizogenes A4 were carried out in Platycodon grandiflorum DC. After 2-4 weeks of inoculation with Agrobacterium rhizogenes hairy roots were formed at root segments in the balloon flower. Optimized growth of hairy roots was obtained in hormone-free MS medium, 6% sucrose and pH 5.8. The pattern of ginsenoside in the transformed roots was not different with that in the ordinary roots.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.163-169
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• 2008

Roots of Ophiorrhiza prostrata D. Don serve as a rich source of camptothecin (CPT), an anticancer drug. Because of the large-scale collection of its roots, the plant has become a threatened species. The present study accomplishes the induction of adventitious roots as a means for the production of CPT as well as for the large-scale propagation of this anticancer drug plant using leaf and internode explants. The biomass yield and CPT content of adventitious roots induced from different explants were compared to roots developed on ex vitro rooted stem cuttings. Adventitious roots were produced on half-strength Murashige and Skoog (MS) medium supplemented with $10.74{\mu}M$ ${\alpha}-naphthaleneacetic$ acid and $2.32{\mu}M$ kinetin at mean fresh weights of 0.753, 0.739 and 0.748 g roots from leaf, internode and shoot, respectively. CPT yield from in vitro derived roots after 50, 80 and 120 days of incubation (0.028, 0.06 and 0.1% dry weight, respectively) was not significantly different from those harvested at the same age from ex vitro rooted (0.03, 0.06 and 0.13%, respectively) stem cuttings. CPT from subcultured roots derived from solid (0.08%) medium was lower than from suspension culture medium (0.12%). Subsequent cultures of the adventitious roots showed a stable production of CPT (0.16%). The yield of CPT from 360-day-old plant-derived roots was 0.19%. Elicitation using methyl jasmonate and acetyl salicylic acid exhibited no enhancement in CPT yield. In vitro propagation through direct shoot regeneration was achieved from the adventitious roots upon transfer to MS medium with $8.87{\mu}M$ $N^6-benzyladenine$ (BA) and $2.46{\mu}M$ indole-3-butyric acid (IBA) with a mean of 21.2 shoots per culture in 50 days. The shoots upon subculture on medium having the same level of BA and IBA underwent rapid proliferation. The shoots transferred to field conditions after in vitro rooting exhibited 95% survival. Adventitious root induction, from leaf and internode explants, enables the feasible production of CPT as well as the large-scale rapid propagation of this species which can safeguard it from extinction.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.88-94
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• 2005

Plant tissue culture studies have been done for the preservation of medicinal plant resources and efficient production of pharmaceutically important secondary metabolites. Micropropagation methods for Cephaelis ipecacuanha have been established and these methods enabled much more efficient propagation of the plants than the conventional methods using seedling or layering. The C. ipecacuanha plants derived from tissue culture grew uniformly in the field and they showed higher alkaloid contents compared to the plants grown from seedlings. Hairy root cultures of C. ipecacuanha and Panax ginseng have been established by infection with Agrobacterium rhizogenes, and the production of important pharmaceuticals by these cultures have been successfully demonstrated. In the case of C. ipecacuanha, the highest alkaloid yields from the hairy roots cultured for 8 weeks were 2.75-fold cephaeline (5.5 mg) and one third emetine (0.7 mg) compared with those from the roots of one-year old plant propagated through shoot-tip culture and cultivated in a greenhouse (2.0 mg cephaeline and 2.0 mg emetine). In the case of P. ginseng, ginsenoside contents in the hairy roots optimally cultured for 4 weeks were much higher than those in the roots of 4-year old field-grown plant. Thus our medicinal plant tissue cultures demonstrate desirable properties. However, they are always exposed to danger of microbial contamination or unexpected trouble of culture facilities. Cryopreservation of plant tissue cultures is a reliable method for long-term preservation. Cryopreservation studies on these cultures are also presented.

• The Plant Pathology Journal
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• v.18 no.4
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• pp.169-178
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• 2002

Orchids are evolutionally known to be the most advanced plants in the order Liliales, and comprise approximately 1,000 genera and 35,000 species world-wide. In Korea, more than 110 species of Orchidaceae have been reported to be cultivated or to be collected in the wild. Orchids aye mostly dependant on orchid mycorrhizae(OM) throughout or in part of their life cycle. The OM endomycorrhizae belonging to basidiomycetes or rarley ascomycetes are needed for orchid seed germination. Various fungi, including plant pathogenic, antagonistic and symbiotic fungi, were isolated from the roots of orchid native to Korea. The OM fungi collected from the roots of Cymbidium goeringii were three species of Rhizoctonia namely, R. repens (anamorph state of Tulsanella repens), R. endophytica (Ceratobasidium cornigerum), and an unidentified species (possibly an anamorph of T. calospora). These symbiotic fungi induced peloton in the cortical cells of orchid roots, and differed biologically and in 18s rDNA sequences from plant pathogenic Rhizoctonia species. Also, the mycorrhyzal fungi enhanced the orchid root absorption of nitrogen sources and minerals from the soil. The activity of mycorrhizal fungal hyphae in the roots caused prevention from pathogenic fungi. In nature, the peloton is observed in the cortical cells of Cymbidium goeriingii roots, indicating mycorrhizal colonization in the native orchid roots. On the other hand, pathogenic fungi such as Fusarium and/or Rhizoctonia species are mostly isolated from commercial orchid plants. These suggest that application of symbiotic mycorrhizal fungi should be needed for orchid cultivation in nurseries and at the time of transplanting.

• The Korean Journal of Mycology
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• v.20 no.2
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• pp.126-133
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• 1992

Using the soils containing several arbuscular mycorrhizae, the degrees of infection on the plant roots were measured with the different level of phosphate added on pot cultures. Infection on the plant roots was independent of the phosphate level for the roots of sorghum, but formation of arbuscular mycorrhizae in the roots was inversely related to the growth of soybean roots. It was concluded that infection of arbuscular mycorrhizae would be related to the phosphate level in the soils. Plants, themselves, were considered to control the infection of arbuscular mycorrhizae under the environments of soils, especially amount of phosphate.

• Journal of Plant Biology
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• v.31 no.4
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• pp.259-266
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• 1988

We investigated the activities of choline kinase, CTP: phosphorylcholine cytidyltransferase, and phosphatase during the greening of etiolated barley seedlings. Activities of choline kinase in leaves increased until 6 hours after illumination and decreased considerably after 6 hours, while activities of CTP: phosphorylcholine cytidyltransferase increased after illumination. On the contrary, changes of these two enzymatic activities showed reverse pattern in roots. The activities of phosphatase which hydrolyze phosphorylcholine decreased in leaves but changed little in roots during greening. The concentration of phosphorylcholine increased in xylem exudate and in roots during greening, while decreased in leaves. These results suggested that more phosphorylcholine arrive in leaves from roots as greening of etiolated barley seedlings.