• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3756-3759
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• 2011

• Analytical Science and Technology
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• v.23 no.2
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• pp.172-178
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• 2010

Glutathione S-transferase is known to play a crucial role in detoxification in many cases. To develop a herbicide detection biosensor, we in this study attempted to immobilize glutathione S-transferase enzyme on solid supports, polystyrene and agarose, and Na-alginate. These matrixes were attractive materials for the construction of biosensors and might also have utility for the production of immobilized enzyme bioreactors. We also compared the activities of glutathione-S-transferase immobilized OsGSTF3 and free OsGSTF3. The specific activity of the free enzyme in solution was 3.3 higher than the immobilized enzyme. These results suggest that 50% of the enzyme was bound with the catalytic site in polystyrene-alkylamine bead and immobilized enzymes showed 80% remaining activity until 3 times reuse.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.645-653
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• 2019

Background: Cytochrome P450 enzymes catalyze a wide range of reactions in plant metabolism. Besides their physiological functions on primary and secondary metabolites, P450s are also involved in herbicide detoxification via hydroxylation or dealkylation. Ginseng as a perennial plant offers more sustainable solutions to herbicide resistance. Methods: Tissue-specific gene expression and differentially modulated transcripts were monitored by quantitative real-time polymerase chain reaction. As a tool to evaluate the function of PgCYP736A12, the 35S promoter was used to overexpress the gene in Arabidopsis. Protein localization was visualized using confocal microscopy by tagging the fluorescent protein. Tolerance to herbicides was analyzed by growing seeds and seedlings on Murashige and Skoog medium containing chlorotoluron. Results: The expression of PgCYP736A12 was three-fold more in leaves compared with other tissues from two-year-old ginseng plants. Transcript levels were similarly upregulated by treatment with abscisic acid, hydrogen peroxide, and NaCl, the highest being with salicylic acid. Jasmonic acid treatment did not alter the mRNA levels of PgCYP736A12. Transgenic lines displayed slightly reduced plant height and were able to tolerate the herbicide chlorotoluron. Reduced stem elongation might be correlated with increased expression of genes involved in bioconversion of gibberellin to inactive forms. PgCYP736A12 protein localized to the cytoplasm and nucleus. Conclusion: PgCYP736A12 does not respond to the well-known secondary metabolite elicitor jasmonic acid, which suggests that it may not function in ginsenoside biosynthesis. Heterologous overexpression of PgCYP736A12 reveals that this gene is actually involved in herbicide metabolism.

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.1-11
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• 2001

New technologies will have a large impact on the discovery of new herbicide site of action. Genomics, combinatorial chemistry, and bioinformatics help take advantage of serendipity through tile sequencing of huge numbers of genes or the synthesis of large numbers of chemical compounds. There are approximately $10^{30}\;to\;10^{50}$ possible molecules in molecular space of which only a fraction have been synthesized. Combining this potential with having access to 50,000 plant genes in the future elevates tile probability of discovering flew herbicidal site of actions. If 0.1, 1.0 or 10% of total genes in a typical plant are valid for herbicide target, a plant with 50,000 genes would provide about 50, 500, and 5,000 targets, respectively. However, only 11 herbicide targets have been identified and commercialized. The successful design of novel herbicides depends on careful consideration of a number of factors including target enzyme selections and validations, inhibitor designs, and the metabolic fates. Biochemical information can be used to identify enzymes which produce lethal phenotypes. The identification of a lethal target site is an important step to this approach. An examination of the characteristics of known targets provides of crucial insight as to the definition of a lethal target. Recently, antisense RNA suppression of an enzyme translation has been used to determine the genes required for toxicity and offers a strategy for identifying lethal target sites. After the identification of a lethal target, detailed knowledge such as the enzyme kinetics and the protein structure may be used to design potent inhibitors. Various types of inhibitors may be designed for a given enzyme. Strategies for the selection of new enzyme targets giving the desired physiological response upon partial inhibition include identification of chemical leads, lethal mutants and the use of antisense technology. Enzyme inhibitors having agrochemical utility can be categorized into six major groups: ground-state analogues, group specific reagents, affinity labels, suicide substrates, reaction intermediate analogues, and extraneous site inhibitors. In this review, examples of each category, and their advantages and disadvantages, will be discussed. The target identification and construction of a potent inhibitor, in itself, may not lead to develop an effective herbicide. The desired in vivo activity, uptake and translocation, and metabolism of the inhibitor should be studied in detail to assess the full potential of the target. Strategies for delivery of the compound to the target enzyme and avoidance of premature detoxification may include a proherbicidal approach, especially when inhibitors are highly charged or when selective detoxification or activation can be exploited. Utilization of differences in detoxification or activation between weeds and crops may lead to enhance selectivity. Without a full appreciation of each of these facets of herbicide design, the chances for success with the target or enzyme-driven approach are reduced.

• The Korean Journal of Ecology
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• v.24 no.3
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• pp.157-168
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• 2001

Herbicides have been used to control weeds for decades. If detoxification upon exposure to herbicides requires considerable amounts of energy, it could affect the pattern of resource allocation to growth and reproduction of crops. We examined the effects of three levels of a herbicide (Control, Low, and High) on germination, growth and reproductive characters of Glycine max treated twice, i.e., before and after seed germination. Since flowering time of G. max was separated into two groups, flowering time was also considered as a variable in this study. The rate of seed germination tended to be higher at the low level of herbicide compared to other levels. Chlorosis and shape variation of leaves were apparent after the second herbicide treatment, but completely disappeared after six weeks of treatment. The herbicide effects on growth characters were somewhat different between early and late flowering plants, but plants treated with both low and high levels of herbicide reduced their growth compared to those in the control group regardless of flowering time. Plants at the high level of herbicide exhibited the highest growth rate later in the season, suggesting that plants compensated to some extent for reduced growth. However, growth reduction among plants at the high level of herbicide was persistent until the end of growing season. Among plants flowered late in the season, plants in the control level bore a higher number of nodules per plant than those in other levels; such a pattern did not exist among plants flowered early in the season. Plants treated with low and high levels of herbicide produced a lower number of flowers than those in the control. Thus, the herbicide examined affected not only the growth and reproductive characters of non-target crops but also the development and growth of root nodules.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.44-49
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• 1987

Present work has been initiated to see if inherent biochemical difference among plants is, in any way, related to the observed selectivity characteristics of preemergence herbicide, alachlor. Application of aqueous solution of alachlor onto three intact plants, soybean, chinese cabbage and barnyard grass resulted in phytotoxicity responses in the testt plants in varying degree. Examination of glutathione (and homoglutathione) contents of the test plants indicated that the phytotoxicity is inversely proportional to the peptide contents of the test plants. It was also noted that four to five water soluble metabolites are readily formed in intact seedling treated with labelled alachlor and glutathionealachlor and homoglutathionealachlor conjugates were tentatatively identified as major metabolites. It is concluded that conjugation reaction involving glutathiones and xenobiotic alachlor, a typical phase II reaction, acts as detoxification reaction in the three test plants and this would, in turn, contribute to observed selectivity of alachlor.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.271-278
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• 1994

Mode of safening action of N-(4-chlorophenyl)maleimide (CPMI) on metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl) acetamide] was investigated in sorghum(Sorghum bicolor L.). CPMI was synthesized by dehydration of N-(4-chlorophenyl)maleamic acid (CPMA) which was obtained from amination with maleic anhydride and 4-chloroaniline. Melting points of CPMA and CPMI (>95% purity) were $200-202^{\circ}C$ and $116-118^{\circ}C$, respectively. Growth response study indicated that seed treatment of CPMI increased tolerance of sorghum shoot to metolachlor approximately threefold. Sorghum shoot was more sensitive to injury caused by metolachlor and CPMI activity than the root. Metolachlor was initially absorbed by sorghum shoot and metabolized to the metolachlor-glutathione conjugate in CPMI-untreated and treated shoots. However, CPMI treatment significantly accelerated metabolism of $[^{14}C]$metolachlor in sorghum shoot, resulting in decrease in metolachlor content and increase in formation of the glutathione conjugate. It was concluded that the protection against metolachlor injury conferred by CPMI appeared to be correlated to detoxification of metolachlor in sorghum shoot tissue.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.452-462
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• 2021

Pretilachlor (PRE) is a common acetanilide herbicide used worldwide. However, its effects on aquatic organisms, particularly marine photosynthetic life, are not sufficiently known. Herein, we evaluated the toxic effects of PRE by physiological and molecular parameters in the photosynthetic dinoflagellate Prorocentrum minimum. The cell density, pigment content, and photosynthetic parameters (F_v/F_m and PI_ABS) were considerably decreased with increased PRE exposure time and doses. In addition, photosynthesis-related genes, PmpsbA, PmpsaA, and PmatpB, were significantly upregulated when exposed to 1.0 mg L^-1 of PRE for 24 h (p<0.001). In 72 h treatment, the relative gene expression was significantly increased (0.1 and 0.5 mg L^-1; p<0.01). In contrast, PmrbcL was decreased or little changed compared to the controls. Reactive oxygen species (ROS) increased after 24 h exposure (p<0.001). However, the transcriptional fold-changes in glutathione S-transferase (GST) were significantly increased (0.5 and 1.0 mg L^-1; p<0.001) at 72 h. These findings suggested that the PmGST might be involved in PRE detoxification in P. minimum. In addition, PRE may affect the photosystem function in phytoplankton similar to other acetanilides, causing severe damage or cell death.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.265-274
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• 2008

Glutathione S-transferases (GSTs) are multifunctional proteins encoded by a large gene family divided into Phi, Tau, Theta, Zeta, Lambda and DHAR classes on the basis of sequence identity. The Phi(F) and Tau(U) classes are plant-specific and ubiquitous. Their roles have been defined as herbicide detoxification and responses to biotic and abiotic stresses. Fifty-two members of the GST super-family were identified in the Arabidopsis thaliana genome, 13 members of which belong to the Phi class of GSTs (AtGSTFs). Based on the sequence similarities of AtGSTFs, 11 BAC clones were identified from Brassica rapa. Seven unique sequences of ORFs designated the Phi class candidates of GST derived from B. rapa (BrGSTFs) were detected from these 11 BAC clones by blast search and sequence alignment. Some of BrGSTFs were present in the same BAC clones indicating that BrGSTFs could also be clustered as usual in plant. They were mapped on B. rapa linkage group 2, 3, 9 and 10 and their nucleotide and amino acid sequences were highly similar to those of AtGSTFs. In addition, in silico analysis of BrGSTFs using Korea Brassica Genome Project 24K oligochip and microarray database for cold, salt and drought stresses revealed 15 unigenes to be highly similar to AtGSTFs and six of these were identical to one of BrGSTFs identified in the BAC clones indicating their expression. The sequences of BrGSTFs and unigenes identified in this study will facilitate further studies to apply GST genes to medical and agriculture purposes.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.449-460
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• 2012

Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the GST gene present in Panax ginseng genome as well as its expression and function. A GST cDNA (PgGST) was isolated from P. ginseng cDNA library, and it showed the amino acid sequence similarity with theta type of GSTs. PgGST in ginseng plant was induced by exposure to metals, plant hormone, heavy metals, and high light irradiance. To improve the resistance against environmental stresses, full-length cDNA of PgGST was introduced into Nicotiana tabacum. Overexpression of PgGST led to twofold increase in GST-specific activity compared to the non-transgenic plants, and the GST overexpressed plant showed resistance against herbicide phosphinothricin. The results suggested that the PgGST isolated from ginseng might have a role in the protection mechanism against toxic materials such as heavy metals and herbicides.