• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.301-305
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• 2003

The effects of inorganic nitrogen sources such as KNO$_3$ and NH$_4$ NO$_3$ on cell growth and production of chlorogenic acid and eleutheroside E derivative were investigated in 5L bioreactor cultures of Eleutherococcus senticosus. The cell growth in the 1/2MS medium containing 15mMKNO$_{3}$. The fresh weight of cells harvested from bioreactor was affected by the concentration ratio of NO$_3$$^{[-10]}$ and NH$_4$$^{+}$ in culture medium. At the viewpoint of secondary metabolite production, the production of chlorogenic acid was affected by the concentration of NH$_4$$^{+}$ in the culture medium, but not by the total concentration of nitrogen sources in the culture medium. Futhermore, eleutheroside E derivative production was also affected by the concentration ratio of NO$_3$$^{[-10]}$ and NH$_4$$^{+}$ in the culture medium. Base on those results, it is suggested that cell growth and production of secondary metabolite(chlorogenic acid and eleutheroside E derivative) could be manipulated by controlling the total concentration of nitrogen sources and the concentration ratio of NO$_3$$^{[-10]}$ and NH$_4$$^{+}$ in the culture medium. medium.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.43-49
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• 2003

Metabolism of a new fungicide ethaboxam by soil fungi was studied. Among the fungi tested, Cunninghamelia elegans produced metabolites from ethaboxam, which were not found in the control experiments. M5, a major metabolite from ethaboxam was firmly identified as N-deethylated ethaboxam by LC/MS/MS and NMR. N-Deethylated ethaboxam has been found as a single metabolite in in vitro metabolism with rat liver microsomes. Ml was proved to be 4-ethyl-2-(ethylamino)-1,3-thiazole-5-carboxamide (ETC) by comparing with the authentic compound. In addition, M2, M3, and M4, and M6 were tentatively Identified by LC/MS/MS as hydroxylated and methoxylated ethaboxams, respectively. Production of the major metabolite, N-deethylated ethaboxam, by the fungus suggested that C. elegans would be an efficient eukaryotic microbial candidate for evaluating xenobiotic-driven mammalian risk assessment.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.106-113
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• 2015

Effects of mineral salts (N, P, K, $Ca^{2+}$, $Mg^{2+}$, and $Fe^{3+}$) on the shoot growth and metabolite production of tea tree were studied using in vitro culture techniques. Among mineral s alts, ${H_2PO_4}^-$ was the most important for enhanced growth rate of tea tree, while $Mg^{2+}$ and $Ca^{2+}$ did not affect plant growth. Removal of ${NH_4}^+$ and $NO_3$ from the culture medium enhanced shoot multiplication compared to other treatments. Metabolite production was variable depending on mineral types and concentration. Removal of $Ca^{2+}$ decreased the production of caffeine; however, other treatments did not influence its production. $Ca^{2+}$, ${NH_4}^+$ and $Fe^{3+}$ were important factors for catechin production in tea tree. These results can be used as the basis for development of technical soil controls suitable for tea tree cultivation in the future.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.3
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• pp.138-149
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• 2002

Plant cell culture provides a viable alternative over whole plant cultivation for the production of secondary metabolites. In order to successfully cultivate the plant cells at large scale, several engineering parameters such as, cell aggregation, mixing, aeration, and shear sensitivity are taken into account for selection of a suitable bioreactor. The media ingredients, their concentrations and the environmental factors are optimized for maximal synthesis of a desired metabolite. Increased productivity in a bioreactor can be achieved by selection of a proper cultivation strategy (batch, fed-batch, two-stage etc.), feeding of metabolic precursors and extraction of intracellular metabolites. Proper understanding and rigorous analysis of these parameters would pave the way towards the successful commercialization of plant cell bioprocesses.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.73-77
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• 2005

Plant-derived natural products have been and will continue to be valuable sources. Elicitors have been employed to modify cell metabolism in order to enhance the productivity of useful metabolites in plant cell/tissue cultures. In this study, several elicitors were used to improve the productivity of useful metabolites and to reduce culture time for archiving high concentration in P. ginseng hairy root cultures. The addition of chitosan, chitosan oligosaccharide and alginate oligosaccharide to the culture of P. ginseng hairy roots caused growth to be inhibited with the increase in elicitor concentration. The usage of the chitosan elicitor and D-glucosamine caused a slight decrease in hairy root growth, whereas total ginseng saponin accumulated slightly with the increase in elicitor concentration. When gel beads were added to the culture medium at the initial period, hairy root growth was enhanced. The maximum growth was 1.35 times higher than that of the control at $1\%$ (w/v). Total ginseng saponin content decreased due to the addition of alginate beads. This would result in consistent diffusion of lower levels of calcium ions during the culture period that promotes biomass growth.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.327-330
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• 1990

The effects of various plant growth regulators, both auxins and cytokinins, on cell growth and berberine production were investigated in cell suspension cultures of Thafictrum rugosum. Indole-%-acetic acid (IAA) was found to be the best for berberine production among five examined plant growth regulators and the optimum concentration of IAA was 1 $\mu \textrm M$. The enhancement compared to control 2, 4-dichlorophenoxyacetic acid (2, 4-D) was more than 60%. Simultaneous addition of cytokinins such as kinetin and 6-benzylamiroyurine (BA) was inhibitory.

• The Plant Pathology Journal
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• v.38 no.2
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• pp.146-158
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• 2022

Changes in physiological and biochemical patterns in lucerne plants caused by the presence of 'Candidatus Phytoplasma australasia', which is one of the significant pathogens causing yield losses in lucerne plants, were investigated. Significant differences were evident in total chlorophyll, chlorophyll a, chlorophyll b, and protein amounts between 'Ca. Phytoplasma australasia'-positive and negative lucerne plants. Stress-related metabolites such as phenol, malondialdehyde, and proline accumulations in 'Ca. Phytoplasma australasia'-positive plants were remarkably higher than those of phytoplasma-negative plants. As a response to disease attack, phytoplasma-positive plants exhibited higher antioxidant enzymes (peroxidase and catalase) and nonenzymatic metabolite responses such as jasmonic and salicylic acids. We state that partial disease responses were revealed for the first time to breed resistant lucerne lines infected by 'Ca. Phytoplasma australasia'.

• Proceedings of the Botanical Society of Korea Conference
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• 1995.06a
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• pp.40-56
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• 1995

During the past two decades, China has seen her great progress in plant biotechnology. Since the Chinese market of herb medicine is huge, while the plant resources are shrinking, particular emphasis has been placed in plant tissue and cell cultures of medicinal plants, this includes fast propagation, protoplast isolation and regeneration, cell suspension cultures and large scale fermentation. To optimize culture conditions for producing secondary compounds in vitro, various media, additives and elicitors have been tested. Successful examples of large scale culture for the secondary metabolite biosynthesis are quite limited : Lithospermum ery throrhizon and Arnebia euchroma for shikonin derivatives, Panax ginseng, P. notoginseng, P. quinquefolium for saponins, and a few other medicinal plants. Recent development of genetic transformation systems of plant cells offered a new approach to in vitro production of secondary compounds. Hairy root induction and cultures, by using Ri-plasmid, have been reported from a number of medicinal plant species, such as Artemisia annua that produces little artemisinin in normal cultured cells, and from Glycyrrhiza uralensis. In the coming five years, Chinese scientists will continue their work on large scale cell cultures of a few of selected plant species, including Taxus spp. and A. annua, for the production of secondary metabolites with medicinal interests, one or two groups of scientists will be engaged in molecular cloning of the key enzymes in plant secondary metabolism.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.8-13
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• 1999

Hypersensitive cell death of plants during incompatible plant-pathogen interactions is one of the efficient defense mechanisms of plants against pathogen infections. For better understanding of the molecular mechanisms involved in the plant hypersensitive response (HR), TMV-induced biotic plant cell death and CuSO4-induced abiotic plant cell death were compared in terms of expression patterns of ten different defense-related genes as molecular markers. The genes include five pathogenesis-related protein genes, two plant secondary metabolite-associated genes, two oxidative stress-related genes and one wound-inducible gene isolated from tobacco. Northern blot analyses revealed that a same set of defense-related genes was induced during both biotic and abiotic cell death but with different time and magnitude. The expression of defense-related genes in tobacco plants was temporarily coincided with the time of cell death. However, when suspension cell cultures was used to monitor the expression of defense-related genes, different patterns of the gene expression were detected. This result implies that three are common and, in addition, also different branches of signaling pathways leading to the induced expression of defense-related genes in tobacco during the pathogen- and heavy metal-induced cell death.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.21-27
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• 2023

In plants, salicylic acid (SA) is a central immune signal that is involved in both local and systemic acquired resistance (SAR). In addition to SA, several other chemical signals are also involved in SAR and these include N-hydroxy-pipecolic acid (NHP), a newly discovered plant metabolite that plays a crucial role in SAR. Recent discoveries have led to a better understanding of the biosynthesis of SA and NHP and their signaling during plant defense responses. Here, I review the recent progress in role of SA and NHP in SAR. In addition, I discuss how these signals cooperate with other SAR-inducing chemicals to regulate SAR.