• Journal of Ginseng Research
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• v.33 no.3
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• pp.206-211
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• 2009

In order to investigate the effects of elicitors on the growth and ginsenoside biosynthesis of ginseng hairy roots, we treated Panax ginseng hairy root with various concentrations of Haliotidis concha according to different time course. Haliotidis concha supplement increased the biomass and ginsenoside accumulation at 10 mg/L concentration. The growth rate of hairy root under a lighter concentration was greater than hairy root treated with a denser concentration. The highest content and productivity of ginsenosides appeared at 2 weeks after the treatment of 10 mg/L Haliotidis concha. The gene expression of squalene synthase, squalene epoxidase, dammarenediol synthase, cycloartenol synthase, $\beta$-amyrin synthase in hairy roots of ginseng were examined by RT-PCR. The Haliotidis concha treatment resulted in the obvious accumulation of the mRNA of triterpene biosynthesis in Panax ginseng hairy root as compared with the control. In this study, Haliotidis concha acts as a kind of elicitor for the production of ginsenosides.

• Molecules and Cells
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• v.27 no.5
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• pp.563-570
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• 2009

We previously isolated the OsCBT gene, which encodes a calmodulin (CaM)-binding protein, from a rice expression library constructed from fungal elicitor-treated rice suspension cells. In order to understand the function of OsCBT in rice, we isolated and characterized a T-DNA insertion mutant allele named oscbt-1. The oscbt-1 mutant exhibits reduced levels of OsCBT transcripts and no significant morphological changes compared to wild-type plant although the growth of the mutant is stunted. However, oscbt-1 mutants showed significant resistance to two major rice pathogens. The growth of the rice blast fungus Magnaporthe grisea, as well as the bacterial pathogen Xanthomonas oryzae pv. oryzae was significantly suppressed in oscbt-1 plants. Histochemical analysis indicated that the hypersensitive-response was induced in the oscbt-1 mutant in response to compatible strains of fungal pathogens. OsCBT expression was induced upon challenge with fungal elicitor. We also observed significant increase in the level of pathogenesis-related genes in the oscbt-1 mutant even under pathogen-free condition. Taken together, the results support an idea that OsCBT might act as a negative regulator on plant defense.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.216-222
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• 2016

BACKGROUND: Polychlorinated biphenyls (PCBs) are one of the most common environmental contaminants. Because of their recalcitrant properties and long-term toxicity, numerous studies have been performed. The toxicological concerns are focused on endocrinological effects of animal. Several different metabolites have been reported, including hydroxy PCBs, PCB quinones, and methylsulfonyl PCBs from animal tissues. However, details in plants have never been studied. It is well-known that plants can produce phytoalexin in response to chemical, physical, or pathological stress.METHODS AND RESULTS: In this study, the several PCBs and hydroxy derivatives were prepared by chemical syntheses. Their effects on secondary metabolite biosynthesis were determined in carrot roots. The levels of 6-methoxymellein were determined in several different treatments, using gas chromatography-mass spectrometry. In general, the concentration of 6-methoxymellein reached a maximum at 2 days and gradually decreased to trace level at 5 days in control experiments. However, the effects of PCBs or hydroxy derivatives were highly dependent on compounds. For example, the maximum concentrations of 6-methoxymellein were observed at 3 days for 2-hydroxy/4-hydroxybiphenyl, while 3,3',4,4',5-pentachlorobiphenyl and 3,5-dichloro-2-hydroxybiphenyl showed a rapid accumulation within 1 day, followed by rapid dissipation to undetectable levels.CONCLUSION: Biphenyl derivatives were effective elicitor of 6-methoxymellein accumulation. In general, hydroxybiphenyls (phenols) more efficiently induced phytoalexin biosynthesis than those without hydroxy groups. It can be concluded that PCBs or their possible metabolites could change the plant secondary metabolism.

• BMB Reports
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• v.38 no.6
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• pp.668-675
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• 2005

A full-length cDNA encoding taxadiene synthase (designated as TmTXS), which catalyzes the first committed step in the Taxol biosynthetic pathway, was isolated from young leaves of Taxus media by rapid amplification of cDNA ends (RACE). The full-length cDNA of TmTXS had a 2586 bp open reading frame (ORF) encoding a protein of 862 amino acid residues. The deduced protein had isoelectric point (pI) of 5.32 and a calculated molecular weight of about 98 kDa, similar to previously cloned diterpene cyclases from other Taxus species such as T. brevifolia and T. chinenisis. Sequence comparison analysis showed that TmTXS had high similarity with other members of terpene synthase family of plant origin. Tissue expression pattern analysis revealed that TmTXS expressed strongly in leaves, weak in stems and no expression could be detected in fruits. This is the first report on the mRNA expression profile of genes encoding key enzymes involved in Taxol biosynthetic pathway in different tissues of Taxus plants. Phylogenetic tree analysis showed that TmTXS had closest relationship with taxadiene synthase from T. baccata followed by those from T. chinenisis and T. brevifolia. Expression profiles revealed by RT-PCR under different chemical elicitor treatments such as methyl jasmonate (MJ), silver nitrate (SN) and ammonium ceric sulphate (ACS) were also compared for the first time, and the results revealed that expression of TmTXS was all induced by the tested three treatments and the induction effect by MJ was the strongest, implying that TmTXS was high elicitor responsive.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.584-588
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• 2007

Elicitors are defined as substances that induce defense responses in plants, which include an increased synthesis of secondary metabolites. Saponin, one of the secondary metabolites, has various physiological effects such as anticancer, antioxidant, cholesterol-lowering activities, etc, in human. This study was carried out to find whether a treatment of soybean sprouts with chitosan as an elicitor, increases saponin contents. Saponin contents in soybean sprouts increased by the chitosan treatment during cultivation, reached the peak on the sixth day, and then decreased. A biosynthesis of group B soyasaponin appeared to be regulated differently. The content of soyasaponin I, a member of group B saponin, was the highest in 250 ppm chitosan-treated soybean sprouts, while the contents of soyasaponin II, III and IV were the highest in 1,000 ppm chitosan-treated soybean sprouts. The content of soyasaponin V changed little in soybean sprouts that had been treated with various concentration of chitosan.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.131-135
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• 2018

Plants produce extrafloral nectar (EFN), liquid of carbohydrates to protect themselves against various insect herbivores through attracting natural enemy, ants, wasp and parasitoids, so EFN production is well known as one of indirect defense mechanisms. In many plants, EFN production is increased or induced when plants are attacked and damaged by insect feeding, whereas there are some plants whose EFN production is not altered or even decreased upon insect attack. The feeding types (chewing or sap feeding) of insects attacking plants also affect EFN production. The objective of this study was to examine how insect herbivore alters production of extrafloral nectar of Impatiens balsamina. Two different types of herbivores, leaf chewing and sap feeding insects, Spodoptera litura and Impatientinum impatiens respectively, are utilized. Plants were mechanically damaged by making holes on leaves with Jasmonic acid (JA) and regurgitate of S. litura added on. Two different densities of aphids were confined on leaves. The results of the study was that mechanical damage and JA or regurgitate addition did not affect EFN production in I. balsamina. Aphid feeding, regardless of density treated, decreased EFN production. The results of the study suggest that production of extrafloral nectar of Impatiens balsamina can be changed by insect feeding, and the effects of insect feeding can depend on the type of insects.

• Journal of Ginseng Research
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• v.38 no.4
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• pp.270-277
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• 2014

Background: The effect of methyl jasmonate (MJ) on ginsenoside production in different organs of ginseng (Panax ginseng Meyer) was evaluated after the whole plant was dipped in an MJ-containing solution. MJ can induce the production of antioxidant defense genes and secondary metabolites in plants. In ginseng, MJ treatment in adventitious root resulted in the increase of dammarenediol synthase expression but a decrease of cycloartenol synthase expression, thereby enhancing ginsenoside biosynthesis. Although a previous study focused on the application of MJ to affect ginsenoside production in adventitious roots, we conducted our research on entire plants by evaluating the effect of exogenous MJ on ginsenoside production with the aim of obtaining new approaches to study ginsenoside biosynthesis response to MJ in vivo. Methods: Different parts of MJ-treated ginseng plants were analyzed for ginsenoside contents (fine root, root body, epidermis, rhizome, stem, and leaf) by high-performance liquid chromatography. Results: The total ginsenoside content of the ginseng root significantly increased after 2 d of MJ treatment compared with the control not subjected to MJ. Our results revealed that MJ treatment enhances ginsenoside production not in the epidermis but in the stele of the ginseng root, implying transportation of ginsenosides from the root vasculature to the epidermis. Application of MJ enhanced protopanaxadiol (PPD)-type ginsenosides, whereas chilling treatment induced protopanaxatriol (PPT)-type ginsenosides. Conclusion: These findings indicate that the production of PPD-type and PPT-type ginsenosides is differently affected by abiotic and biotic stresses in the ginseng plant, and they might play different defense mechanism roles.

• KSBB Journal
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• v.13 no.2
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• pp.174-180
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• 1998

Enhanced production of (10-deacetyl) baccatin III and related taxanes was observed in suspension cultures of Taxus baccata Pendula. six % of initial glucose and sucrose concentration increased 10-deacetyl baccatin III production 3.5 and 2.5 times, respectively. Methyl jasmonate, as an elicitor, increased taxane production. Time course changes of taxane production after methyl jasmonate addition showed that baccatin II and 10-deacetyl baccatin III were detected first and paclitaxel, 10-deacetyl taxol and cephalomanine were produced in sequence. Feeding experiments with $500{\mu}M$ of benzoic acid increased 10-deacetyl baccatin III production 10 times. Baccatin III production was also increased 8 times by feeding of $500{\mu}M$ of lysine as a precursor.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.132-136
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• 1996

To investigate the characteristics of immobilized peppermint (Mentha piperita) cells, dry cell weight (DCW), change of cell viability, and oil productivity of the immobilized cells were determined. Peppermint cells were immobilized in polyurethane (PU) foams of $5{\times}5{\times}5$ mm and cultured in a shaking flask. The maximum DCW was 2.1 mg per foam piece after 20 days of cultivation and the cell density was approximately 420 mg per flask containing 200 foams in 200 ml medium. For the first five days of cultivation, the cell viability was about 80$%$ and decreased to 70$%$ during 5 to 20 days of cultivation. The maximum oil productivity, 148 mg/l was achieved after 40 days of cultivation. The immobilized cells were also cultivated in a bioreactor, equipped with a round spiral type impeller, containing 2, 400 PU foams. The cell viability after 30 days of cultivation with chitosan as an elicitor in the bioreactor was 67$%$ and DCW was 2.0 mg per foam piece. Though the cell viability was relatively high in the bioreactor system, the oil productivity was relatively lower than that of the flask system.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.321-323
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• 2003

Hyoscyamine and scopolamine are the pharmaceutically valuable anticholinergic drugs. The aim of our study is to increase the contents of both hyoscyamine and scopolamine by means of elicitation. Various biotic elicitors derived from 3 fungi and 1 yeast were inoculated to the hairy root cultures. When homogenate and supernatant of elicitors treated with hairy root cultures, that of yeast elicitor was only increased scopolamine production. However, all of the fungal elicitors did not influenced the productions of scopolamine and hyoscyamine. Our results will contribute to mass production of tropane alkaloids by hairy root cultures of Scopolia parviflora.