• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.57-65
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• 1998

This study was conducted to develop a resistant tobarro against Potato virus Y (PVY) by transformation of the plants with genetically engineered viral genes. The complimentary DNAs (cDNAS) of potato virus Y-necrosis strain (PVY-Vn) replicase mutant genes (3'-deleted, 5'-deleted and ADD-mutant Nlbs) were synthesized through RT-PCR by using purified PVY-VN RNA and synthesized primers, and cloned in the sense orientation into a plant expression vector (pMBPI), The cDNAS of the genes were transferred into Agrobacterium tumefaciens LBA 4404, and then transformed into tobacco (Nicotiana tabacum cv. Burley 21) plants. Regenerated plants were tested for PVY resistance by inoculation test; 13 transgenic plants including 7 for 3'-deleted Nlb, 3 for 5'-deleted Nlb, and 3 for ADD-mutant Nlb appeared to be resistant at 4 weeks after inoculation with PVY-VN. Among the 13 transgenic tobacco plants, 8 plants had no symptom up to 14 weeks after inoculation. The progenies ($T_1$) from self-fertilization of the transgenic lines varied 0.0% to 81.2% in their resistance (% of resistant plants). The analysis of Nlb-31deleted, -5'deleted and -ADD mutant in the $T_1$ plants by polymerase chain reaction (PCR) showed that Nlb-3'deleted, -5'deleted and -ADD mutants were detected in all of the resistant plants. These results suggest that the PVY resistance was inherited in the $T_1$ generation.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.281-291
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• 2010

The rice CHLH gene encodes the $Mg^{2+}$-chelatase H subunit, which is involved in chlorophyll biosynthesis. Growth of the chlorophyll-deficient oschlh mutant is supported by mitochondrial activity. In this study, we investigated the activity of mitochondrial respiration in the illuminated leaves during oschlh seedling development. Growth of mutant plants was enhanced in the presence of 3% sucrose, which may be used by mitochondria to meet cellular energy requirements. ATP content in these mutants was, however, significantly lowered in light conditions. Low cytosolic levels of NADH in illuminated oschlh mutant leaves further indicated the inhibition of mitochondrial metabolism. This down-regulation was particularly evident for oxidative stressresponsive genes in the mutant under light conditions. Hydrogen peroxide levels were higher in oschlh mutant leaves than in wild-type leaves; this increase was largely caused by the impairment of the expression of the antioxidant genes, such as OsAPXl, OsRACl, and OsAOXc in knockout plants. Moreover, treatment of mesophyll protoplasts with ascorbic acid or catalase recovered ATP content in the mutants. Taken together, these results suggest that the light-mediated inhibition of mitochondrial activity leads to stunted growth of CHLH rice seedlings.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.19-26
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• 1990

To examine the effects of sequence variations near the transcriptional start site on the rate of formation of the open complexes at bacteriophage $\lambda P_{R}$ promoter, two mutant promoters were created by site-specific mutagenesis using synthetic oligonucleotides. Mutant I coatains changes at positions -3 and -4 from TT to CC, thus having a 6-bp long G/C stretch between -10 region and transciptional start site (+1). Mutant II has changes at positions -5 and -6 from GG to AA, thereby having a 9-bp long A/T stretch between positions -11 and -3. Selective filter binding assays were performed to measure the rate of formation of the open complexes between the wild-type or two mutant $P_{R}$ promoters on 664 bp fragments and E. coli RNA polymerase at two temperatures. At 37.deg.C, the wild-type and two mutants showed similar rates for the formation of open complex. The second order rate constant $k_{a}$ and $\tau _{int}$, as determined from the .tau.-plot analysis, were $(6.0\pm0.4)\times10^{6}M^{-1}sec^{-1}$ and $11\pm5$sec, respectively. At 18.deg.C, however, the wild-type and two mutant promoters showed differences in the kinetic parameters. k for the wild-type promoter was (2.2$\pm$0.1)\times 10^{6}M^{-1}sec^{-1}$ and $\tau _{int}$ was 76$\pm$sec. Mutant I and II exhibited differences mainly in the rate of isomerization ($\tau_{int,I}=91\pm$10 sec, int,II=34$\pm$ sec), whereas the second order rate constant $k_{a}$ was similar to the wild type value. This result implies that at $18^{\circ}C$, the isomerization rate is determined by both protein conformational change and DNA melting, which are separable kinetically according to the 3-step mechanism of Roe et al.(1984,1985), and that the base changes affected mainly the rate of DNA melting as predicted.lting as predicted.

• Journal of Life Science
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• v.19 no.7
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• pp.852-858
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• 2009

The homeostasis of the pyridine nucleotide pool [NAD(P)H and NAD(P)$^+$] is maintained in Rhodobacter sphaeroides mutant strains defective in the cytochrome bci complex or the cytochrome c oxidases in terms of its concentration and redox state. Aerobic derepression of the puf operon, which is under the control of the PrrBA two-component system, in the CBB3 mutant strain of R. sphaeroides was shown to be not the result of changes in the redox state of the pyridine nucleotides and the ubiquinone/ubiquinol pool. Using the bc$_1$ complex knock-out mutant strain of R. sphaeroides, we clearly demonstrated that the inhibitory effect of cbb$_3$, oxidase on spectral complex formation is not caused indirectly by the redox change of the ubiquinone/ubiquinol pool.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.296-300
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• 2002

Bacterial cell surface components are the major factors responsible for pathogenesis and bioremediation. In particular, the surface of a Gram-negative bacterium cell has a variety of components compared to that of a Gram-positive cell. In our previous study, we isolated an isogenic mutant of Bradyrhizobium japonicum, which exhibited altered cell surface characteristics, including an increased hydrophobicity. Polyacrylamide gel electrophoretic analysis of the lipopolysaccharide (LPS) in the mutant demonstrated that the O-polysaccharide part was completely absent. Meanwhile, a gel permeation chromatographic analysis of the exopolysaccharide (EPS) in the mutant demonstrated that it was unaltered. Since LPSs are known to have several anion groups that interact with various cation groups and metal ions, the mutant provided an opportunity to examine the direct role of LPS in metal binding by B. japonicum. Using atomic absorption spectrophotometry, it was clearly demonstrated that LPS was involved in metal binding. The binding capacity of the LPS mutant to various metal ions $(Cd^{2+},\;Cu^{2+},\;Pb^{2+},\;and\;Zn^{2+})$ was 50-70% lower than that of the wild-type strain. Also, through an EPS analysis and desorption experiment, it was found that EPS and centrifugal force had no effect on the metal binding. Accordingly, it would appear that LPS molecules on B. japonicum effect the properties, which precipitate more distinctly metal-rich mineral phase.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.227-232
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• 2015

Genetic polymorphisms of pvdhfr and pvdhps genes of Plasmodium vivax were investigated in 83 blood samples collected from patients in the Philippines, Bangladesh, and Nepal. The SNP-haplotypes of the pvdhfr gene at the amino acid positions 13, 33, 57, 58, 61, 117, and 173, and that of the pvdhps gene at the positions 383 and 553 were analyzed by nested PCR-RFLP. Results suggest diverse polymorphic patterns of pvdhfr alone as well as the combination patterns with pvdhps mutant alleles in P. vivax isolates collected from the 3 endemic countries in Asia. All samples carried mutant combination alleles of pvdhfr and pvdhps. The most prevalent combination alleles found in samples from the Philippines and Bangladesh were triple mutant pvdhfr combined with single mutant pvdhps allele and triple mutant pvdhfr combined with double wild-type pvdhps alleles, respectively. Those collected from Nepal were quadruple mutant pvdhfr combined with double wild-type pvdhps alleles. New alternative antifolate drugs which are effective against sulfadoxine-pyrimethamine (SP)-resistant P. vivax are required.

• Journal of Radiation Industry
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• v.10 no.1
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• pp.13-20
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• 2016

In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine>Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.375-382
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• 2011

A chemical, MNU-induced hulless barley mutant line designated as 'Mutant 98 (M98)' was developed from a Korean hulless waxy barley cultivar, 'Chalssalbori'. The objective of the study was to determine the genetic basis of 'M98' and the possibility of using 'M98' as breeding parent to improve lysine level. Compared to 'Chalssalbori', 'M98' had large embryo and higher lysine content in both the embryo and endosperm. Significantly different lysine content in 'M98' and the other high-lysine barley mutant stocks was observed for two years. However, the genotype by year interaction was not significant. 'M98' was higher than the other high-lysine barley mutant stocks in the percentage of lysine of total amino acid composition (0.75%). The trait of shrunken endosperm of 'M98', which was typical in the high-lysine mutants, was inherited by a single recessive gene. Based on seed morphology and lysine content of $F_1$ seeds, 'M98' had a genetically different gene from the other high-lysine mutants for shrunken endosperm. Segregation of $F_2$ for plump/shrunken endosperm did not fit the expected ratio of Mendelian inheritance except for only one cross combination (GSHO1784 (lys1)/M98). The amino acid analysis of $F_5$ and $F_6$ progenies from the cross between 'M98' and 'Chalssalbori' revealed that the attempt to increase the range of lysine content of plump lines did not go beyond the limit of the average high-lysine barley germplasm.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.6
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• pp.159-165
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• 2018

The Hippo pathway was originally discovered in Drosophila by genetic screening and it has been shown to be conserved in various organisms including human. Until now, the essential roles of Hippo pathway in regulating cell proliferation, apoptosis, tumorigenesis, and organ size control is extensively studied. Currently, Mats1/2 (Mob1a/1b), one of the important components in Hippo pathway, mutant mice were generated which has abnormal phenotype such as resistance to apoptosis and spontaneous tumorigenesis. Of note, Mats1/2 mutant mice also showed dental malocclusion. Therefore, in this study, we have evaluated the bone phenotype of Mats1/2 mutant mice. Although the mRNA expressions of Mats1 or Mats2 were observed in both osteoclastogenesis and osteoblastogenesis, the increase of Mats1 level was most prominent during osteoblastogenesis. The RANKL-induced osteoclast differentiation from bone marrow-derived macrophages (BMMs) was unaltered upon Mats1/2 mutation; however, the osteoblast differentiation using calvarial pre-osteoblasts was significantly reduced in Mats1/2 mutant mice compare to that of wild type mice. In accordance with in vitro results, Mats1/2 mutant mice showed decreased bone volume as well as increased trabecular separation in ${\mu}CT$ analyses. These results may provide novel prospect of the probable linkage between Hippo pathway and bone homeostasis.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.117-125
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• 2022

Until recently, four types of cellobiose-fermenting Saccharomyces cerevisiae strains have been developed by introduction of a cellobiose metabolic pathway based on either intracellular β-glucosidase (GH1-1) or cellobiose phosphorylase (CBP), along with either an energy-consuming active cellodextrin transporter (CDT-1) or a non-energy-consuming passive cellodextrin facilitator (CDT-2). In this study, the ethanol production performance of two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-2 (N306I) with GH1-1 or CBP were compared with two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-1 (F213L) with GH1-1 or CBP in the simultaneous saccharification and fermentation (SSF) of cellulose under various conditions. It was found that, regardless of the SSF conditions, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the best ethanol production among the four strains. In addition, during SSF contaminated by lactic acid bacteria, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the highest ethanol production and the lowest lactate formation compared with those of other strains, such as the hydrolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-1 with GH1-1, and the glucose-fermenting S. cerevisiae with extracellular β-glucosidase. These results suggest that the cellobiose-fermenting yeast strain exhibiting low energy consumption can enhance the efficiency of the SSF of cellulosic biomass.