• Journal of Plant Biotechnology
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• 제5권1호
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• pp.51-57
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• 2003

Doubled haploids have long been recognized as a valuable tool in plant breeding since it not only offers the quickest method of advancing heterozygous breeding lines to homozygosity, but also increased the selection efficiency over conventional procedures due to better discrimination between genotypes within any one generation. Salt tolerant mutants were obtained in rice the variety, 'Hawsungbyeo', through in vitro mutagenesis of in vitro cultured anther-derived calli. Various doses (30, 50, 70 and 90 Gy) of gamma ray were applied to investigate the effect of radiation on callus formation on medium containing 1% NaCl, green plant regeneration, frequency of selected doubled haploid mutants and of the salt tolerant screen. It was demonstrated that the dose of 30 and 50 Gy gamma rays had significant effects on callus formation, regeneration and selection of salt tolerance. No tolerant lines were obtained from non-mutagenized cultures. From gamma ray irradiated cultures, five tolerant lines ($M_2$generation) at germination stage and 13 tolerant lines ($M_3$genoration) at seedling stage were obtained. The frequency of salt tolerant mutants indicates that anther culture applied in connection with gamma rays is an effective way to improve salt tolerance.

• Journal of Life Science
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• 제9권1호
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• pp.22-25
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• 1999

In order to study the mechanism for the adaptation to salt stress, we mutagenized budding yeast Saccharomyces cerevisiae with Ethylmethane sulfonate, and isolated salt-tolerant mutants. Among the salt-tolerant mutants, two strains exhibit additional temperature sensitive phenotype. Here, we report that these two salt-tolerant mutants are specific to {TEX}$Na^{+}${/TEX} rather than general osmotic stress. These mutant strains may contain mutations in the genes involved in {TEX}$Na^{+}${/TEX} home-ostasis.

• 생명과학회지
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• 제17권5호
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• pp.641-645
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• 2007

염 내성 돌연변이체를 선발하기 위하여, ethyl methane sulfonate(EMS)로 처리된 돌연변이 종자 집단을 사용하였다. 150 mM NaCl 고염 스트레스 하에서 종자 발아 내성을 보이는 세 종류의 EMS 돌연변이체를 선발하였다. 세 종류의 EMS 돌연변이체들 중, salt tolerance 42-14(sto42-14) 돌연변이체는 175 mM NaCl 고농도에서 종자 발아율이 대조구(WT)에 비해 7배 이상의 높은 발아율을 보였다. 또한 내염성 sto42-14 돌연변이체는 glucose(Glc)에 대해서도 비감수성을 갖고 있음을 관찰되었고, 흥미롭게도 sto42-14돌연변이체에 $20{\mu}M$ gibberellin(GA)을 처리한 결과, 대조구에 비해 하배축과 뿌리의 생장이 억제됨을 관찰할 수 있었다. 이러한 결과를 바탕으로, 고염 내성 sto42-14 돌연변이체는 Glc 뿐만 아니라 GA호르몬 반응에도 관련되어져 있음을 알 수 있다.

• Journal of Life Science
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• 제11권1호
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• pp.30-33
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• 2001

To identify novel components involved in the salt stress signaling pathway of yeast cells, we used mTn3-mediated transposon tagging library and screened mutants displaying enhanced tolerance to NaCl. Southern blot analysis indicated that more than 80% of the sre (salt resistant) mutants possessed only one insertion of the tagged transposon, suggesting that the NaCl resistant phenotype was mediated by a single gene in the majority of the mutants. To define the role of SRE genes in the salt stress signaling pathway, we introduced NaCl stress-inducible ENA1::LacZ construct into the sre mutants and examined the expression of ${\beta}$-galactosidase activity. Interestingly, we could detect high level of ${\beta}$-galactosidase activity without any NaCl treatment in the sre-3, 4, 6 and 7 mutants. These results indicate that SRE-3, 4, and 7 gene are components of salt stress signaling pathway of yeast cells.

• 방사선산업학회지
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• 제4권4호
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• pp.325-334
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• 2010

Transcriptional regulation in response to salt in mutant lines was investigated using oligonucleotide microarrays. In order to characterize the salt-responsive genes in rice, the expression profiles of transcripts that responded to salt-treatment were monitored using the microarrays. In the microarray analysis, among 37,299 reliable genes, 5,101, 2,758 and 2,277 genes were up-regulated by more than 2-fold using the salt treatment, while the numbers of down-regulated genes were 4,619, 3,234, and 1,878 in the WT, ST-495, and ST-532, respectively. From genotype changes induced by gamma ray mutagenesis, 3,345 and 2,397 genes were up-regulated, while 2,745 and 2,075 genes were down-regulated more than 2-fold in the two untreated mutants lines compared with untreated WT, respectively. A total of 3,108 and 2,731 genes were up-regulated more than 2-fold, while 3,987 and 3,660 genes were down-regulated by more than 2-fold in the salt treatment of the two mutants lines compared with the salt treated WT, respectively. The expressions of membrane transporter genes such as OsAKT1, OsKUP, and OsNAC increased more severely in ST-495 and ST-532 than in the WT. The expressions of the proline accumulation related genes such as OsP5CS and OsP5CR were also markedly increased in the salt tolerant mutants when compared to the WT plant.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2019년도 추계학술대회
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• pp.146-146
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• 2019

• 방사선산업학회지
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• 제4권4호
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• pp.307-312
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• 2010

Plants have evolved physiological, biochemical and metabolic mechanisms to increase their survival under the adverse conditions. This present study has been performed to select salt-tolerant rice mutant lines through in vivo and in vitro mutagenesis with gamma-rays. For the selection of the salt-tolerant rice mutants, we conducted three times of selection procedure using 1,500 gamma ray mutant lines resulted from an embryo culture of the original rice cv. Dongan (wild-type, WT): first, selection in the a nutrient solution with 171 mM NaCl; second, selection under in vitro condition with 171 mM NaCl; and third, selection in a reclaimed saline land. Based on a growth comparison of the entries, out of the mutant lines, two putative 2 salt tolerant (ST) rice mutant lines, ST-87 and ST-301, were finally selected. The survival rate of the WT, ST-87 and ST-301 were 36.6%, 60% and 66.3% after 7 days in 171 mM NaCl treatment, respectively. The WT and two salt tolerant mutant lines were used to analyze their genetic variations. A total of 21 EcoRI and Msel primer combinations were used to analyze the genetic relationship of among the two salt-tolerant lines and the WT using the ABI3130 capillary electrophoresis system. In the AFLP analysis, a total of 1469 bands were produced by the 21 primer combinations, and 700 (47.6%) of them were identified as having polymorphism. The genetic similarity coefficients were ranged from 0.52 between the ST-87 and WT to 0.24 between the ST-301 and the WT. These rice mutant lines will be used as a control plot for physiological analysis and genetic research on salt tolerance.

• 한국초지조사료학회지
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• 제43권1호
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• pp.42-49
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• 2023

The plant-specific NAC transcription factors control various biological processes, including plant development and stress responses. We have isolated an ANAC032 gene, one of the NAC transcription factor family, which was highly activated by multi-abiotic stresses, including high salt and drought in Arabidopsis. Here, we generated transgenic plants constitutively expressing ANAC032 and its knockout to identify the functional roles of ANAC032 in Arabidopsis under abiotic stress responses. The ANAC032-overexpressing plants showed enhanced tolerance to salinity and drought stresses. The anac032 knockout mutants were observed no significant changes under the high salt and drought conditions. We also monitored the expression of high salt and drought stress-responsive genes in the ANAC032 transgenic plants and anac032 mutant. The ANAC032 overexpression upregulated the expression of stress-responsive genes, RD29A and ERD10, under the stresses. Thus, our data identify that transcription factor ANAC032 plays as an enhancer for salinity and drought tolerance through the upregulation of stress-responsive genes and provides useful genetic traits for generating multi-abiotic stress-tolerant forage crops.

• Journal of Plant Biotechnology
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• 제38권1호
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• pp.94-104
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• 2011

Salt stress is a major environmental factor influencing plant growth and development. To identify salt tolerance determinants, we systematically screened salt sensitive rice mutants by use of the Activator/Dissociation (Ac/Ds) transposon tagging system. In this study, we focused on the salt sensitive mutant line, designated SSM-1. A gene encoding a NAC transcription factor homologue was disrupted by the insertion of a Ds transposon into SSM-1 line. The OsNAC075 gene (EU541472) has 7 exons and encodes a protein (486-aa) containing the NAC domain in its N-terminal region. Sequence comparison showed that the OsNAC075 protein had a strikingly conserved region at the N-terminus, which is considered as the characteristic of the NAC protein family. OsNAC075 protein was orthologous to Arabidopsis thaliana ANAC075. Phylogenetic analysis confirmed OsNAC075 belonged to the OsNAC3 subfamily, which plays an important role in response to stress stimuli. RT-PCR analysis showed that the expression of OsNAC075 gene was rapidly and strongly induced by stresses such as NaCl, ABA and low temperature ($4^{\circ}C$). Our data suggest that OsNAC075 holds promising utility in improving salt tolerance in rice.

• Journal of Plant Biotechnology
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• 제30권3호
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• pp.227-232
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• 2003

Radiation technique has been used to develope mutant rice. Suwon 345 rice seeds were irradiated with 250 Gy gamma ray. Morphological characteristics of the variants in M$_{8}$ generation were observed and random amplified polymorphic DNA(RAPD) analysis was carried out. Plant height, panicle length, 1,000 grain weight and lodging were very different in mutants compared with donor cultivar. RAPD analysis showed that polymorphic bands were presented in several primers of the mutants. In comparison with original variety, variants were classified into four group through UPGMA analysis. A group has mutation trait in panicle length, B group in plant height and C group in 1,000 grain weight. Among mutants, no. 46 and 147 was ranked as salt tolerance and the malonaldehyde content of these mutants was more increased than that of original variety. Valuable mutants obtained will be useful for developing new cultivars and for studing gene function in molecular level.l.