• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.88-101
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• 2013

Eating quality of rice attracts more and more attention from rice-eating consumers in the recent years. Thus, improvement of eating quality of cooked rice has become one of the most important breeding goals in japonica rice. Here, the generation of transgenic japonica rice with improved eating quality and grain yield are reported. Overexpression of OsSbe1 gene encoding rice starch branching enzyme 1 was driven by 35S promoter. Eleven independent homozygous $T_3$ transgenic lines were characterized and had shown higher palatability (71.2 ~ 72.6) than wild type Gopum (70.4). Moreover, transgenic rice lines showed an increase in 1000-grain weight and number of spikelets per panicle compared with the wild type. The yield of milled rice was 562.8 ~ 596.7 kg/10a in eight $T_3$ lines, but 542.1 kg/10a in wild type. Gene expression analyses in mRNA transcription and enzyme activity levels suggest that improved eating quality is due to the up-regulation of OsSbe1 gene.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.832-835
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• 1994

The ${alpha}$-amylase gene of Bacillus licheniformis has been cloned and two mutant ${alpha}$-amylase genes of which histidine 235 was changed to glutamine (H235Q) and aspartic acid 328 to glutamic acid (D328E) have been produced by site-directed mutagenesis. The kinetic parameters, optimum pH and thermostability of wild type(WT) and these two mutant amylases expressed in E. coli MC1061 have been compared after purification. The $K_m$ values of WT, H235Q and D328E ${alpha}$-amylases were 0.22%, 0.73%, and 0.80% respectively, when using starch as the substrate. The $V_max$ values of wild type ${alpha}$ -amylase and mutant ${alpha}$-amylases were 0.6-0.7%/minute, and did not show any significant differences among them. The optimum pH of D328E ${alpha}$-amylase was shifted to more acidic pH. Also, the thermostability of H235Q ${alpha}$-amylase was increased compared to the wild type ${alpha}$-amylase.

• Journal of Plant Biology
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• v.39 no.4
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• pp.273-278
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• 1996

Arabidopsis mutants deficient in flavonoid and sinapate ester (tt4 and fah1-7, respectively) were evaluated in vivo and in vitro to study the possible role of flavonoid compounds in pollen tube growth. In vivo, we investigated pollen tube growth in the pistils of the mutants and wild type(Ler). The growth of pollen tubes was significantly different among the three genotypes. In the fal1-7 pistils, the tubes grew to a greater length relative to those of the wild type or tt4. To examine in vitro pollen tube growth, a solid medium was devised for pollen germination and subsequent growth. In vitro, the identical result was obtained; fahl-7 pollens developed the longest tubes and elongated most rapidly. Therefore, the growth response of pollen tubes to phenolic compounds was examined by adding quercetin or sinapate ester in various concentrations to the media. Quercetin enhanced both germination rate and tube growth in the pollens of the mutants and the wild type, especially in tt4. In contrast, sinapate ester inhibits pollen germination and pollen tube growth in three genotypes. These results suggest that flavonoids and related phenolic compounds have physiological role in the plant reproductive system.

• Journal of Marine Life Science
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• v.1 no.1
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• pp.56-62
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• 2016

In the present study, to clarify a possible relevance of blind-side hypermelanosis to chronic stress in cultured flounders, P. olivaceus, a serial experiment was tried with comparison of biochemical stress factors between wild type and hypermelanic type in cultured olive flounders. The mean size of experimental animal was total length 21.5±0.42 cm and body weight 87.5±6.1 g. The initial malpigmented area rate on the blind side skin was 0.63±0.12% and 16.7±4.7%, respectively, in the wild type and the hypermelanic type. The stress factors surveyed in the experiment were glucose (GLU), total protein (TP), cortisol, free type-thyroid hormones (FT₃ and FT₄) in plasma, and also moisture, crude protein, crude lipid, and crude ash in body muscle. As a result, GLU and TP were higher in hypermelanic type than in wild type. Plasma cortisol was also higher in hypermelanic type than in wild type. In FT₃ and FT₄, any difference between two groups was not observed. In body nutrient factors, the moisture and the crude ash in body composition were not different between two groups, but the crude protein was low and the crude lipid was high in the hypermelanic type. Therefore, it is concluded that the blind-side hypermelanosis of cultured flounders could be related with a chronic stress.

• Korean Journal of Pharmacognosy
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• v.10 no.3
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• pp.119-124
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• 1979

Both wild peony and cultivated peony demonstrated a slight effect and tranquilizer of anti-convulsion on the strychinine and picrotoxine but the wild plant was more effective. The methanol extract of cultivated peony root demonstrated a weak effect of muscle loosening but its mixture with water extractable fraction did not have this effect in contrast to the case wild type whose methanol extract mixture with water extractable fraction still retained a strong anti-convulsional muscle loosening effect. Therefore, it is concluded that wild peony root has more analgesic and muscle loosening effect than the cultivated counterpart has.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.791-807
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• 2017

The type II secretion system (T2SS), which transports selected periplasmic proteins across the outer membrane, has rarely been studied in nonpathogens or in organisms classified as Betaproteobacteria. Therefore, we studied Cupriavidus metallidurans (Cme), a facultative chemilithoautotroph. Gel analysis of extracellular proteins revealed no remarkable differences between the wild type and the T2SS mutants. However, enzyme assays revealed that native extracellular alkaline phosphatase is a T2SS substrate, because activity was 10-fold greater for the wild type than a T2SS mutant. In Cme engineered to produce three Ralstonia solanacearum (Rso) exoenzymes, at least 95% of their total activities were extracellular, but unexpectedly high percentages of these exoenzymes remained extracellular in T2SS mutants cultured in rich broth. These conditions appear to permit an alternative secretion process, because neither cell lysis nor periplasmic leakage was observed when Cme produced a Pectobacterium carotovorum exoenzyme, and wild-type Cme cultured in minimal medium secreted 98% of Rso polygalacturonase, but 92% of this exoenzyme remained intracellular in T2SS mutants. We concluded that Cme has a functional T2SS despite lacking any abundant native T2SS substrates. The efficient secretion of three foreign exoenzymes by Cme is remarkable, but so too is the indication of an alternative secretion process in rich culture conditions. When not transiting the T2SS, we suggest that Rso exoenzymes are probably selectively packaged into outer membrane vesicles. Phylogenetic analysis of T2SS proteins supports the existence of at least three T2SS subfamilies, and we propose that Cme, as a representative of the Betaproteobacteria, could become a new useful model system for studying T2SS substrate specificity.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.108-113
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• 2014

Pseudomonas aeruginosa and Vibrio vulnificus are Gram-negative human pathogens, which exert their virulence through quorum sensing (QS) regulation. The infection of these pathogens have been known to be mediated by biofilm formation in many cases and this study carried out the time-course analysis of biofilm formation depending on the QS regulation in P. aeruginosa and V. vulnificus. In P. aeruginosa, our results demonstrated that QS-deficient mutant better attached to surface at initial stage of biofilm formation, but poorly proceeded to the maturation of the biofilm structure, while wild type less attached at initial stage but developed highly structured biofilm at late stage. Because of this, the quantitative comparison of biofilm formation between wild type and the QS mutant showed the reversion; the QS mutant formed more biofilm until 10 h after inoculation than wild type, but wild type formed much more biofilm after 10 h than QS mutant. V. vulnificus has been reported to form more biofilm with the mutation on QS system. When we performed the same time-course analysis of the V. vulnificus biofilm formation, the reversion was not detected even with prolonged culture for 108 h and the QS mutant always forms more biofilm than wild type. These results indicate that the QS regulation negatively affects the attachment at early stage but positively facilitates the biofilm maturation at late stage in P. aeruginosa, while the QS regulation has a negative effect on the biofilm formation throughout the biofilm development in V. vulnificus. Based on our results, we suggest that the developmental stage of biofilm and bacterial species should be considered when the QS system is targeted for biofilm control.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.535-540
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• 1990

Bacitlus sphaericus ts-Dl290 was characterized comparatively with the wild type strain 1593 by themeasurements of the biosynthesis of total DNA, RNA and protein on the temperature-shift culturesat permissive temperature of $30^{\circ}C$ and at nonpermissive temperature of $42^{\circ}C$. The growth patterns of the wild type strain and ts-Dl290 were similar at $30^{\circ}C$, but at 4Z C the mutant almost did not grow (temperature-sensitivity). When the growth temperatures of both stains were shifted-up from $30^{\circ}C$ to $42^{\circ}C$ after a 4 hour culture, their growths were normal, but when shifted-down from $42^{\circ}C$ to $30^{\circ}C$ after a 4 h culture, the mutant did not grow. When shifted up from $30^{\circ}C$ to $42^{\circ}C$ after a 4 hculture, the DNA syntheses of the two strains were at a normal rate for 1 h, but after 1 h the biosynthesesdecreased. The rate of DNA synthesis of the wild type strain at the nonpermissive temperature was about 93%, and that of the mutant was about 50% of the ratio of the wild type strain, and the RNA synthesis of the wild type strain was maintained for 3 h, and that of the mutant for 2 h. Thereafter the RNA synthesis decreased, and the synthesis of proteins in the both strains were similarlykept high for 8 h. The reversibility of the DNA synthesis of the mutant at $42^{\circ}C$ was lessened whenthe culture times were increased.re times were increased.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.244-249
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• 2006

In order to select the best strains to have the feasibility of Cheonghju brewing, 10 wild type yeast strains from 300 different types of Nuruk were investigated on their ethanol resistance, resistance to glucose and flocculation. The amounts of alcohol, organic acids, and volatile compounds, Brix, pH were also examined for the alcoholic beverages made with the 10 selected strains. Almost all strains showed alcohol production activities in the medium containing 18%(v/v) ethanol and 29%(w/v) glucose. The strains 90-2 showed a higher flocculation activity than other strains. Strains 54-3, 90-2 and 91-5 produced more alcohol than control strain (7.42%(w/w)) when fermented with wild type yeast strains. In addition, alcoholic beverages containing low acetic acid also showed low levels of total acidity. GC/MS analysis of the product showed 4 alcohols, 11 esters and 1 acid as volatile compounds. Selected strains were tentatively identified as Phichia sydowiorum (91-5), Zygosaccharomyces cidri (192-2 and 271-4), and as Saccharomyces cerevisiae (18-2, 54-3, 90-2, 91-2, 98-2, 99-5 and 272-7) by BIIOLOG method.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.89-95
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• 1993

The Inhibiting activity of newly synthesized phenol (E-series) and triazine (T-series) derivatives was evaluated by using thylakoid membranes extracted from cyanobacteria (Anacystis nidulans $R_2$). There were no significant differences between phenol derivatives and dinoseb to the thylakoid membrane extracted from wild type in the Hill reaction. However, a phenol derivative, E-24 which has no -Cl at phenyl ring, did not show any activity. The longer the length of R substituents was in phenol derivatives, the lower inhibiting activity was in the Hill reaction. Triazine derivatives, T-27, T-28, T-40, T-41, T-47 and T-48 were also compared with diuron and atrazine. Among triazine compounds, T-27 and T-28 showed 10 and 30 times activity as high as atrazine to wild type, respectively. Other triazine derivatives, T-40, T-41, T-47 and T-48 showed low inhibiting activity to wild and mutant type. A structural difference of T-27 and T-28 from T-40, T-41, T-47 and T-48 was the presented of -C-NH-. Both T-27 and T-28 were very closely associated with serine, an amino acid located at the 264th position of D1 protein because of the resistant ratio(R/S) to mutant G-264 were higher than that of atrazine.