• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.187-189
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• 2004

To isolate a mutant strain which overproduces tryptophan, mutants of Candida rugosa were screened after EMS (ethyl methane sulfonate) mutagenesis. Fluorotryptophan, a tryptophan analogue, was used for selection of a tryptophan-overproducing mutant after mutagenesis. Among 50 mutants, several candidates were selected based on intracellular tryptophan content. Amino acid analysis results showed that C3 was the best strain because it had the highest amount of tryptophan among the mutants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1017-1021
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• 2004

To isolate a mutant which overproduces threonine and tryptophan, mutants of Saccharomyces cerevisiae were screened after UV and EMS mutagenesis. Hydroxynorvaline, a Thr analogue was used for selection of a Thr-overproducing mutant after UV mutagenesis. Among 31 mutants, TC 5-1 was selected as the strain candidate, based on amino acid analysis. TC 5-1 was then treated by EMS mutagenesis for Trp overproduction. Eight mutants were selected using fluorotryptophan for Thr and Trp overproducing strains. Amino acid analysis results showed that TC 6-1 was the best strain since it had the highest amount of Thr and Trp among mutants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.247-253
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• 1997

Development of soybean cultivars with great nodulation and high nitrogen fixation activity, derived mostly from mutagenesis, may decrease inputs of chemical fertilizer nitrogen into the soil-plant system. Soybean seeds (cv. Jangyupkong, Hwanggeumkong, and Geomjungkong 1) were treated with three different levels of EMS (ethyl methanesulfonate) concentration(30, 50, and 70mM). Increasing the doses of EMS resulted in decreased field emergence rate of seeds, whereas it did not increase M$_2$ mutation frequencies. This indicated that the most efficient concentration of EMS was 30mM for generating mutants. Extensive mutagenesis of Sinpaldalkong 2 with 30mM EMS was undertaken to isolate soybean mutants with greater nodulation. Approximately 8, 200 M$_2$ families were screened for greater nodulation on 5 mM nitrate after inoculation with Bradyrhizobium japonicum strain YCK213-KFCC-10728. Mutant SS-2 nodulated more than the wild type. Comparison of supernodulation between SS-2 and two nts mutants(nts 1007 and nts 1116) revealed that SS-2 showed the supernodulation character at an earlier growth stage than the two nts mutants. Further studies should be needed to characterize the difference in timing of nodulation between SS-2 and nts mutants.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.119-126
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• 2008

Since somatic embryogenesis combined with ethylmethane sulfonate(EMS) treatments is the most efficient technique for mutagenesis, the embryogenic capacity of four soybean cultivars was evaluated at different EMS concentrations, treatment times, and preculture durations. Two to 4 mm long immature cotyledons were placed in induction medium after EMS treatment, and the numbers of somatic embryos formed per explant were counted four weeks after culture initiation. We observed genotypic differences in the efficiency of somatic embryogenesis from immature embryos among four cultivars treated with different concentrations of EMS for six hours. Cultivars, Sinpaldalkong 2 and Jack, displayed highly efficient somatic embryogenesis regardless of EMS concentration, whereas very low efficiency or no survival was observed in Jinju 1 and Iksannamulkong cultivars. Preculture duration did not influence the efficiency of somatic embryogenesis. Because Sinpaldalkong 2 exhibited the best somatic embryogenesis, much higher concentrations of EMS were used to test somatic embryo formation under different periods of time in this cultivar. Three and six hour treatments with both 1 and 2 mM EMS yielded higher embryo formation than longer periods of time. Increasing the time with embryos in 2 mM EMS caused a reduction in somatic embryogenesis in Sinpaldalkong 2, but many chlorophyll-deficient soybean variants were identified in the $M_1R_0$ and $M_2R_1$ generations. In addition to Jack, Sinpaldalkong 2 is a good genotype for plant regeneration from EMS-treated immature embryo cultures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.5
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• pp.442-448
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• 1993

The aims of the work were to examme the variability induced by EMS (ethyl methanesulfonate) mutagenesis of soybean plants, and to isolate mutants altered in nodulation and other growth characters. Seeds of two soybean cultivars, ‘Hwanggeumkong’ and ‘Baegunkong’ were treated with 30 and 50mM EMS(pH 7.0) for 6 hours and were planted directly in the field. Field emergency of$M_1 seed was averaged to be 61.0%, and frequency of plants with chlorophyll-deficient sectors of the first trifoliolate is about 0.7%. Regardless of varieties and does of EMS, $M_1 plant injury at harvest was present in plant height, pod and seed number per plant when compared to those of original-type soybean plants. The $M_2 variability of nodulation process induced by EMS treatment was found to be narrower than that of shoot dry weight. On the basis of the occurrence of chlorophyll-deficient plants, mutated cell frequency within $M_1 seed ranged from 5.3% to 84.2%, suggesting that mutation frequency on the $M_1 seed induced by EMS occurred partly and randomly regardless of varieties and doses of EMS. The putative mutant, which had more nodulation than original-type plant, was short in plant height. Sparse-nodulating soybean mutant was lower in leaf chlorophyll content and showed reduced growth.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.435-438
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• 2003

Iron required by all organisms is related with diverse biological processes. Most eukaryotes need extra iron to maintain their nutrition balance. However, extra iron supplement gives many problem to solubility in the cells. To increase the bio-availability of iron in cells, yeast was applied to carry the iron with solubility. Selection of yeast mutants with enhanced iron uptake were performed by mutagenesis using the alkylation agent EMS. Eleven mutant strains with enhanced iron uptake were selected by the measurement of iron content with atomic absorption spectrometer. The iron content in mutants was 1.5- to 2.5-fold more than that in wild-type. These mutants could be served as iron-fortified nutrients for food and feed.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.55-62
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• 2018

In the present study in vitro mutagenesis was used to study the effect of gamma irradiation and EMS on callus induction, morphogenesis and production of multiple shoots from different explants of Citrullus colocynthis (L.) Schrad. Gamma radiations (5 kR to 20 kR) and certain chemicals have been effected on plant growth developments and changes of biochemical metabolisms in plants. Murashige and Skoog (MS) medium containing with auxins such as NAA, IAA, 2,4-D (0.5 ~ 2.0 mg/l), cytokinines BAP, kn TDZ, (0.5 ~ 2.5 mg/l), L-Glutamic acid (1 ~ 2 mg/l) and Coconut milk (10 ~ 20%). After 5 weeks on induction media, explants and callus (EC) were exposed to 5 kR, 10 kR, 15 kR and 20kR, of gamma radiation and treated with 1, 2, 3, 4 and 5 mM ethyl methane sulphonate (EMS) for 30 min. The highest percentage of callusing was observed (70%) stem irradiated with 5 kR and significantly decrease in fresh and dry weight of callus in the below 4 kR doses and above 20 kR doses, there was a progressive decrease in the fresh weight and dry weights when compared to control callus. Maximum percentage of plantlet regeneration (59%) was induced from callus exposed to 15 kR gamma irradiation on MS media fortified with 2.0 mg/l 2,4-D + 2.0 mg/l BAP + 2.0 mg/l L-glutamic acid. Increase in gamma irradiation dose above 15 kR and 5 mM EMS reduced regeneration capacity of callus. Doses higher than 20 kR and 7 mM EMS was lethal to micropropagated plants of Citurullus colocynthis.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.324-329
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• 2020

Reed (Phragmites spp.) is a rhizomatous plant of the Poaceae family and is known as high tolerant plant to heavy metal contaminants. This plant is widely recognized as a Cd root-accumulator, but improved heavy metal tolerance and uptake capacity are still required for phytoremediation efficiency. To enhance capacity of hyperaccumulator plants, ethyl methane sulfonate (EMS) as chemical mutagen has been introduced and applied to remediation approaches. This study aimed to select EMS-mutagenized reeds representing high Cd resistance and large biomass and to investigate their ability of Cd accumulation. After 6 months cultivation of M₂ mutant reeds under Cd stress conditions (up to 1,500 µM), we discovered seven mutant individuals that showed good performances like survivorship, vitality, and high accumulation of Cd, particularly in their roots. Compared to wild type (WT) reeds as control, on average, dry weight of mutant type (MT) reeds was larger by 2 and 1.5 times in roots and shoots, respectively. In addition, these mutant plants accumulated 6 times more Cd, mostly in the roots. In particular, MT8 reeds showed the greatest ability to accumulate Cd. These results suggest that EMS mutagenesis could generate hyperaccumulator plants with enhanced Cd tolerance and biomass, thereby contributing to improvement of phytoremediation efficiency in Cd-contaminated soil or wastewater. Further studies should focus on identifying Cd tolerance mechanisms of such EMS-mutagenized plants, developing techniques for its biomass production, and investigating the practical potential of the EMS mutants for phytoremediation.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.348-354
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• 2006

Homogenized prothallus of 6 species (Cyrtomium falcatum, Cyrtomium caryoptideum var. coreanum, Dryopteris varia, Asplenium incisum, Camptosous sibiricus and Phyllitis scolopendrium) were treated with gamma radiation or by chemical mutagenesis with EMS, NMU, $NaN_3$ and colchicine to assess their sensitivities for each treatments and also with the aim of inducing mutations. Generally, decrease of proliferation ratio was dose-dependent and time-dependent. Based on proliferation ratio, optimum dose of gamma irradiation was $5{\sim}10krad$ except in D. varia with 20krad. Optimum condition of EMS treatment was considered as 50mM for 3h and for NMU as $5{\sim}10mM\;for\;1{\sim}3h$. Optimum condition of $NaN_3$ treatment was considered as $0.5{\sim}1mM\;for\;1{\sim}3h$. For colchicine, there were significant differences between species as to the proliferation ratios of prothallus for each treatment.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.374-380
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• 2006

With the aim of inducing mutation in fern Cyrtomium caryoptideum var. coreanum, rhizome segments of In vitro-grown cultures were treated with chemical mutagens such as EMS, NMU and colchicine. Based on regeneration ratios, sensitivities for each treatments were assessed and also optimum treatment condition of each mutagens was explored. Optimum concentration for EMS treatment was considered to be 20 to 50mM and for NMU 5 to 10mM. NMU was found to be more effective in inducing chlorophyll and morphological variations than EMS. The RAPD were performed to check the genetic modification of phenotypical variants. As a result, polymorphic DNA band patterns between wild type and variants were observed by two 10-mer primers.