• Korean Journal of Weed Science
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• v.7 no.1
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• pp.64-73
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• 1987

Field and greenhouse trials were conducted to evaluate application variables including spray volume, surfactant, and simulated rain affecting phytotoxicity of glyphosate for enhancing efficacy of postemergence herbicides. Glyphosate phytotoxicity was increased by addition of surfactants, L-77 and Triton CS-7 to glyphosate solution in Artmesia princeps and Equisetum arvense and addition of Triton CS-7 to glyphosate solution enhanced control of Trifoliurn repens. Simulated rain within 4 or 8 hours after glyphosate application reduced glyphosate phytotoxicity. However, addition of L-77 and Triton CS-7 to glyphosate solution increased glyphosate phytotoxicity reduced by simulated rain in Artmesia princeps and Trifolium repens.

• Korean Journal of Microbiology
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• v.30 no.1
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• pp.42-46
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• 1992

From the soil environment which is treated with herbicides. we isolated strain having high resistance against glyphosate. After being identified. the isolated strain was turned out to be Pseudomc~nu.c~c ~paciua nd to have intense tolerance lo the 10 mM glyphosate. The isolated strain shows slow, growth rate about twenty hours in glyphosate comparing with that in inorganic phosphate. As a result of confirming the p~~sitioonf glyphosate resistant gene. it was proved to exist in chromosome. After cloning it into E coli C600, transformants E. coli THC-101 and plasmid pGR19 were obtained.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.130-133
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• 1986

Glyphosate and 2,4-D were introduced into the vascular systems of Robinia pseudo-acacia L. (3-5cm diameter) with a syringe-type pressure injector in May, 1985. Robinia pseudo-acacia L. were completely controlled by 3 or 6 ml of 3050ppm glyphosate per tree and 6ml of 1000ppm 2,4-D per tree. Herbicidal efficacy was more effective by 6m1 of combined solutions of 1525ppm glyphosate and 500ppm 2,4-D per tree.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.341-344
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• 1997

Calli were induced from the cotyledon and the hypocotyl of alfalfa and the callus lines were tested for the resistance to glyphosate in the liquid medium containing 0.01-3.00 mM glyphosate. Some resistant cell lines were selected from the gradual increase of glyphosate concentration and the lines resistant to 10 mM glyphosate were analyzed with EPSPS activity. Vigorous callus proliferation from the cotyledon and the hypocotyl was observed from the MS medium containing 1 mg/L 2,4-D and 0.5 mg/L kinetin. The hypocotyl was thought to be better explant source for callus induction than the cotyledon. $ID_{50}$ (Inhibition Dosage of 50%) to glyphosate was between 0.1 mM and 0.2 mM level. A49-10G and A58-10G cell lines selected as resistant to 10 mM glyphosate had 8.0 and 9.1 fold increased EPSPS activity to those of the control lines, respectively.

• Journal of The Korean Society of Clinical Toxicology
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• v.14 no.2
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• pp.144-150
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• 2016

Purpose: Glyphosate is a widely used non-selective herbicide. Previous studies have shown that glyphosate has genotoxicity, and that even low-doses of glyphosate can cause DNA damage. Melatonin is a hormone produced and secreted by the pineal gland that is known to be a potent anti-carcinogen, anti-oxidant, and genetic protector. This study was conducted to investigate the genoprotective effect of melatonin against glyphosate in human blood lymphocytes. Methods: Human peripheral blood was obtained from 15 young, healthy volunteers and cultured under four different toxicologic conditions. The four groups consisted of a control group, glyphosate only group (300 ng/mL), glyphosate with low level of melatonin group ($50{\mu}M$), and glyphosate with high level of melatonin group ($200{\mu}M$). The mean Sister Chromatid Exchange (SCE) frequency of each group was then analyzed. Results: Glyphosate exposed groups had a higher mean SCE frequency ($10.33{\pm}2.50$) than the control group ($6.78{\pm}2.31$, p<0.001). Interestingly, the group that received a low-level of melatonin had a lower mean SCE frequency ($8.67{\pm}2.58$) than the glyphosate-only group, while the group that received a high level of melatonin had a much lower mean SCE frequency ($8.06{\pm}2.50$) than the glyphosate-only group. There was statistical significance. Conclusion: Melatonin exerted a potent gene protective effect against the genotoxicity of glyphosate on human blood lymphocytes in a dose-dependent fashion.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.230-239
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• 2012

Coconut (Cocos nucifera L) is one of the predominant plantation crops in Sri Lankan economy which is known to have existed for over thousands of years. During the past decades coconut production had been reduced by a significant quantity. The usage of poor quality planting materials is a major reason for the low coconut production. Thus much attention needs to be paid in coconut nurseries. Weed management is a critical management practice in the nursery. Though glyphosate application is becoming popular in nurseries it can affect weeds as well as coconut seedlings growth. Therefore the effects of glyphosate were evaluated by determining the growth of shoot and root of coconut seedlings. Poly bag nursery was prepared and three treatments were used. Treatments were no glyphosate and manual weeding ($T_1$), application of glyphosate 1.08 ai kg $ha^{-1}$ at 2 monthly interval ($T_2$) and application of glyphosate 1.44 ai kg $ha^{-1}$ at 2 monthly interval ($T_3$). Application of glyphosate at early stage of seedling growth had a no significant effect on growth parameters tested. However, the concentrations of glyphosate negatively affected numbers, volumes and dry weights of secondary, tertiary and quaternary roots at the latter stage of seedling growth. The leaf area and the height of seedling were significantly reduced by the highest concentration of glyphosate. Among the growth parameters tested, seedling girth and shoot dry weight were not affected by the application of glyphosate. These results revealed that the usage of glyphosate at both concentrations negatively affected root growth of coconut seedlings. Based on these results, the both concentration levels of glyphosate should be applied to coconut nurseries before sprouting the seed nuts.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.350-354
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• 2017

Conyza canadensis is the weed species which most frequently develops resistance to glyphosate in many agricultural crop fields. The continuous use of glyphosate has resulted in the spontaneous occurrences of resistant biotypes. This research was conducted to investigate the response of suspected C. canadensis biotypes to glyphosate. Seeds of C. canadensis were collected from 18 sites in tangerine orchards in Jeju province of Korea. In the preliminary screening, 6 resistant and 12 susceptible biotypes were found at the recommended glyphosate rate ($3.28kga.i.ha^{-1}$). The susceptible biotypes were completely killed at the field application rate whereas the resistant biotypes were initially injured but recovered 14 days after glyphosate application. This is the first case of glyphosate resistance found in Korea despite the national ban on genetically modified glyphosate tolerant crops cultivation. Extended monitoring should be conducted to understand how widely spread the glyphosate resistant C. canadensis is and to estimate the severity of this weed problem in the tangerine orchards of Korea.

• Journal of Plant Biology
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• v.30 no.1
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• pp.69-77
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• 1987

From the single cell cultures of haploid tobacco (Nicotiana tabacum L. cv. NC 2326) glyphosate-resistant plants were regenerated. After treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and then inoculated onto the LS medium supplemented with 1 mM glyphosate, the single cells survived formed colonies and calluses in 65 and 95 days after culture, respectively, and then whole plants were regenerated in 0.1 mM glyphosate-containing medium from the selected calluses. There was no difference in fresh weight and shikimate content between the selected and normal haploid calluses. When sprayed with 0.1 mM glyphosate, the shikimate contents in the regenerated and normal plants were 0.659 and 20.816 mol/g fr. wt., while that in other normal plants which were not sprayed was 0.921. In addition, the calluses induced from the regenerated plants grew without showing any retardation when treated with glyphosate. These results indicate that the secelcted calluses and regenerated plants are resistant to glyphosate.

• YAKHAK HOEJI
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• v.45 no.4
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• pp.347-351
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• 2001

A rapid and sensitive method for the determination of glyphosate, a phosphated amino acid herbicide, in whole blood is presented. After removal of protein, the whale blood was purified by using the anion exchange resin (Dowex 1), and derivatized with 9-fluorenylmethyl chloroformate (FMCL). Derivatized glyphosate from blood sample was injected onto a Whatman partisil 10SAX column and separated with 0.1M phosphate buffer (pH 2.5) and acetonitrile (ratio=3:1). The high performance liquid chromatography-fluorescence detection gave the detection limit of 86pg and linearity of 0.9999 in the range of 0.25 $\mu$g/ml and 25 $\mu$g/ml. The recoveries of glyphosate added to the blood samples were ranged from 75.3% to 100.4% compared to the samples prepared in water. The derivatized glyphosate was stable at various acidity and temperature. This method has been successfully applied to the blood samples of lethal intoxication with the herbicide glyphosate.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1384-1390
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• 2018

Glyphosate inhibits the target enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway. A mutant of EPSPS from Pantoea sp. was identified using site-directed mutagenesis. The mutant showed significantly improved glyphosate resistance. The mutant had mutations in three amino acids: Gly97 to Ala, Thr 98 to Ile, and Pro 102 to Ser. These mutation sites in Escherichia coli have been studied as significant active sites of glyphosate resistance. However, in our research, they were found to jointly contribute to the improvement of glyphosate tolerance. In addition, the level of glyphosate tolerance in transgenic Arabidopsis confirmed the potentiality of the mutant in breeding glyphosate-resistant plants.