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Park Y.-H.,Yeungnam University | Lee S.-G.,Andong National University | Ahn D.J.,Gyeongbuk Provincial Agricultural Research and Extension Services | Kwon T.R.,Gyeongbuk Provincial Agricultural Research and Extension Services | And 3 more authors.
Journal of Ginseng Research | Year: 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. © The Korean Society of Ginseng. Source


Park Y.-H.,Yeungnam University | Chung J.Y.,Ajou University | Ahn D.J.,Gyeongbuk Provincial Agricultural Research and Extension Services | Kwon T.R.,Gyeongbuk Provincial Agricultural Research and Extension Services | And 4 more authors.
Biological Control | Year: 2015

Forty endophytic fungi isolated from ginseng plants were screened to identify metabolites that had antifungal activity against ginseng microbial pathogens. The metabolites from the fungi were extracted from the liquid culture filtrates using ethyl acetate and then evaluated in vitro for antimicrobial activity against ginseng pathogens (. Alternaria panax, Botrytis cinerea, Colletotrichum panacicola, Cylindrocarpon destructans, Rhizoctonia solani, and Phytophthora cactorum). Six of the fungi (. Colletotrichum pisi, Fusarium oxysporum, Fusarium solani, Phoma terrestris, unknown 1 and 2) showed effective antimicrobial activity against all or some of the ginseng pathogens, with the extract of P. terrestris showing the strongest antimicrobial activity. The extract also showed inhibitory activity against spore germination of the pathogens. Gas chromatography-mass spectrometry (GC-MS) analysis of P. terrestris extract revealed that forty-one compounds were present in metabolites containing mainly N-amino-3-hydroxy-6-methoxyphthalimide (32% of the total metabolites) and 5H-dibenz [B, F] azepine (7%). Treatment with P. terrestris extract also caused morphological changes and reduced expression of the genes involved in mycelial growth and virulence. Treatment also induced defense-related genes in detached Arabidopsis leaves that were inoculated with the pathogens. These results indicate the antimicrobial potential for use of metabolites extracted from the ginseng endophytic fungi as alternatives to chemicals for biocontrol. © 2015 Elsevier Inc. Source


Park S.U.,Chungnam National University | Ahn D.-J.,Gyeongbuk Provincial Agricultural Research and Extension Services | Jeon H.-J.,Gyeongbuk Provincial Agricultural Research and Extension Services | Kwon T.R.,Gyeongbuk Provincial Agricultural Research and Extension Services | And 4 more authors.
Journal of Ginseng Research | Year: 2012

An light-emitting diode (LED)-based light source was used as a monochromatic light source to determine the responses of raw ginseng roots (Panax ginseng Meyer) to specific emission spectra with respect to the production of ginsenosides. The ginsenoside content in the ginseng roots changed in response to the LED light treatments at 25°C relative to the levels in the control roots that were treated in the dark or at 4°C for 7 d. Ginseng roots were exposed to LEDs with four different peak emission wavelengths, 380, 450, 470, and 660 nm, in closed compartments. Compared with the control 4°C-treated roots, roots that were treated with 450 and 470 nm light showed a significantly increased production of ginsenosides (p<0.05), with increases of 64.9% and 74.1%, respectively. The contents of the ginsenosides Rb2, Rc, and Rg1 were significantly higher (p<0.05) in the 450 and 470 nm-treated root samples. The ratio of protopanaxadiol ginsenosides (Rb 1, Rb 2, Rc, and Rd) to protopanaxatriol ginsenosides (Rg 1, Rg 2, Re, and Rf) was significantly higher (p<0.05) in the 450 and 470 nm-treated root samples than in the control 4°C-treated roots. This is the first report that demonstrates the increase and conversion of ginsenosides in raw ginseng roots in response to exposure to LED light. © The Korean Society of Ginseng. Source

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