• Proceedings of the Zoological Society Korea Conference
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• 한국동물학회 1994년도 한국생물과학협회 학술발표대회
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• pp.166.2-166
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• 1994

• Korean Journal of Microbiology
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• 제13권3호
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• pp.101-108
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• 1975

Physiological effects of 2,4-D on the growth of Chlorella ellipsoidea were investigated culturing the alage in the MN4 media containing 0. $10^{-4}/M$ and $4<\times}10^{-4}M$ 2,4-D. During 6 days culture were taken to analysis with respect to overall growth, photosynthesis, respiration and chemical composition. Results obtained from the experiment were as follows : 1) The growth of chlorella was increased at $10^{-4}M$ and decreased at $4{\times}10^{-4}M$ of 2,4-D concentrations 2) At $10^{-4}M$ pf 2,4-D cpncentration, the activity of photosynthesis enhanced relative to contro. while at $4{\times}10^{-4}M$ it was not changed. In both concentrations, however, the rate of respiration was down from the control. 3) At $10^{-4}M$ 2,4-D, the concentration of carbondrate metabolites was not changed relative to control, while significant increase in the concentrations of proteins and nucleic acids was observed. On the other hand at $4{\times}10^{-4}M$ of 2,4-D concentrations, all the metabolites including carbohydrates, proteins and nucleic acids were descreased. 4) It is concluded that 2,4-D at $10^{-4}M$ concentration accelerates the growth of chlorella by promoting the activities of photosynthesis and biosynthesis of proteins and nucleic acids.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제32권3호
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• pp.353-356
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• 1987

To find out the effect of 2.4-D on growth response and fruit quality of strawberry, by leaf treatment (spray) of 120l/10a of 2.4-D(amine salt 40%) 10 ppm solution at flowering stage of 1st cluster, the experiment was carried out in the P-E film covered green-house. The strawberry plant showed the epinastic growing response with long petiole and petide and increased the evolution of ethylene from leaves and fruits after 2.4-D spraying. Therefore, the peak of picking time was accerated about 15 days according to the higher amount of ethylene evolution from strawberry plants, and the yield of fruit increased about 18% by improving the average weight of a fruit.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제11권12호
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• pp.4922-4927
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• 2010

In order to investigate whether the ethanol extract of Acanthopanax sp. might inhibit herbicide-induced DNA damage and erythrocyte damage, the suppression of the oxidative DNA damage of lymphocyte and erythrocyte damage in the presence of the extract were evaluated by comet assay and hemolysis assay, respectively. Phenoxy herbicides, named 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) and bipyridyl herbicide paraquat induced oxidative DNA damages of lymphocytes. However, the oxidative DNA damage by 2,4-D, 2,4,5-T or paraquat was inhibited in vitro upon treating Acanthopanax extract. Moreover, the erythrocyte damage was also suppressed in vitro by Acanthopanax extract treatment.

• Korean Journal of Plant Tissue Culture
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• 제21권1호
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• pp.7-14
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• 1994

Immature zygotic embryos of five Korean soybean cultivars cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) produced somatic embryos without forming an intervening callus. The highest frequency (up to 90%) of somatic embryo formation was obtained when zygotic embryos were cultlued on medium containing 1 to 2 mga 2, 0-D in four cultivars. However the frequency was highly variable to the cultivars. Transversely sliced primary somatic embryo halves were also capable of forming secondary embryos at frequencies of up to 70% when cultured on medium containing 0.1 to 1 mg/L 2,4-D. Somatic embryos formed on zygotic embryos cultured on medium containing 0.1 to 0.2 mg/L 2,4-D had two cotyledons more frequently than one horn-type cotyledon and those on medium containing 0.5 to 4mg/L 2,4-LD had a horm-type cotyledon at a prominently higher freequency. However somatic embryos on medium containing 10mg/L or higher concentrations of 2,4-D were usually shunted at the globular stage even after transfer to medium containing lower concentrations of 2,4-D or other growth regulators. non somatic embryos with one or two cotyledons or a hem-type cotyledon were transferred to medium containing $GA_3$, those with two cotyledons converted to plantlets at a higher frequency (25%) than the others.

• Proceedings of the Zoological Society Korea Conference
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.135.1-135
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• 1997

No Abstract, See Full Text

• Journal of Applied Biological Chemistry
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• 제42권2호
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• pp.57-61
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• 1999

Seven numerically dominant 2-methyl-4-chlorophenoxyacetic acid (MCPA)-degrading bacteria were isolated from agricultural soils. The isolates utilized the herbicide MCPA as a sole carbon source, producing significant biomass in MCPA mineral medium. They exhibited diverse herbicide degradation capabilities, but most of them grew very slowly in mineral medium containing herbicide. The chromosomal DNA patterns of the isolates obtained by polymerase chain reaction amplification of repetitive extragenic palindromic sequences were distinct from each other. One isolate, SH3, which was identified as Sphingomonas species by fatty acid methyl ester analysis, was able to degrade 5 different phenoxyacetic acid herbicides within 4 days. This strain contains two plasmids, and the smaller one has a crucial role in herbicide degradation. MCPA treated into agricultural soils without indigenous MCPA-degraders persisted for a long time, but the application of the isolate SH3 resulted in rapid decline of MCPA concentration in the soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제58권4호
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• pp.331-335
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• 2013

Buckwheat sprout is used as vegetable, and also flour for making noodles, and so on. Currently, information about tissue culture in buckwheat is limited and restricted to micro-propagation. We carried out somatic embryogenesis and plant regeneration using hypocotyl segments as explant of the cultivated buckwheat species, Fagopyrum esculentum which differs from existing studies in the growth regulator combinations used. Maximum callus regeneration was induced on MS medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) $2.0mg{\cdot}L^{-1}$, benzyladenine (BA) $1.0mg{\cdot}L^{-1}$ and 3% sucrose. Friable callus was transferred to solidified MS media containing BA ($1.0mg{\cdot}L^{-1}$) with various concentrations of 2,4-dichlorophenoxyacetic acid for the induction of embryogenesis. The optimum concentrations of growth regulators (for regeneration of plantlet) were indole-3-acetic acid ($2.0mg{\cdot}L^{-1}$), Kinetin ($1.0mg{\cdot}L^{-1}$), BA ($1.0mg{\cdot}L^{-1}$). Only 2,4-D did not show any significant effect on callus induction or embryogenesis. Regeneration of embryonic callus varied from 5% to 20%. Whole plants were obtained at high frequencies when the embryogenic calli with somatic embryos and organized shoot primordia were transferred to MS media with 3% sucrose. The main objective of this research was to develop an efficient protocol for plant regeneration for common buckwheat, and to apply in future for genetic transformation.

• Journal of Ginseng Research
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• 제38권3호
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• pp.220-225
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• 2014

An efficient in vitro protocol has been established for somatic embryogenesis and plantlet conversion of Korean wild ginseng (Panax ginseng Meyer). Wild-type and mutant adventitious roots derived from the ginseng produced calluses on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid and 0.3 mg/L kinetin; 53.3% of the explants formed callus. Embryogenic callus proliferation and somatic embryo induction occurred on MS medium containing 0.5 mg/L 2,4-dichlorophenoxyacetic acid. The induced somatic embryos further developed to maturity on MS medium with 5 mg/L gibberellic acid, and 85% of them germinated. The germinated embryos were developed to shoots and elongated on MS medium with 5 mg/L gibberellic acid. The shoots developed into plants with well-developed taproots on one-third strength Schenk and Hildebrandt basal medium supplemented with 0.25 mg/L 1-naphthaleneacetic acid. When the plants were transferred to soil, about 30% of the regenerated plants developed into normal plants.

• Safety and Health at Work
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• 제12권1호
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• pp.127-132
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• 2021

Background: Herbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides. Methods: Ninety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method. Results: Sixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20-40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = -2.347) were found to be significantly associated with MDA level. Conclusion: The results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.