• Korean Journal of Plant Tissue Culture
• /
• v.26 no.2
• /
• pp.127-132
• /
• 1999

Protoplasts were isolated from the leaf mesophyll tissue of in vitro 4-weeks-old Arabidopsis thaliana and cultured in MS liquid medium supplemented with 2.0 mg/L NAA, 0.5 mg/L BAP and 9% mannitol in the dark at $25^{\circ}C$. When protoplast-derived microcolonies were dehydrated, the frequency of callus induction enhanced approximately 7-fold higher compared with non-dehydrated microcolonies in CP medium. Fifty callus lines were selected from dehydrated microcolonies. Shoots were efficiently initiated from the green spots of the selected shoot forming calli cultured on MS regeneration medium supplemented with 0.05 mg/L IAA, 7.0 mg/L 2-iP and 30 g/L sucrose under continous illumination for 4 weeks. Shoot regeneration frequencies (calli regenerating at least one shoot) were 3.5%~56%. Histological observations of shoot forming callus revealed that tracheary elements initiated from inner compact cells, and that meristemoids developed to shoot primordia and shoots. Roots were induced from these regenerating shoots on MS medium without phytohormones. These regenerants were successfully transplanted into potting soil. Morphological characterization of 50 protoplast-derived plants showed that the frequency of normal type was 78%.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1659-1664
• /
• 2012

TSAHC [4'-(p-toluenesulfonylamido)-4-hydroxychalcone] is a promising antitumorigenic chalcone compound, especially against TM4SF5 (four-transmembrane L6 family member 5)-mediated hepatocarcinoma. We evaluated the potential of TSAHC to inhibit the catalytic activities of nine cytochrome P450 isoforms and of P-glycoprotein (P-gp). The abilities of TSAHC to inhibit phenacetin O-deethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), amodiaquine N-deethylation (CYP2C8), diclofenac 4-hydroxylation (CYP2C9), omeprazole 5-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and midazolam 1'-hydroxylation (CYP3A) were tested using human liver microsomes. The P-gp inhibitory effect of TSAHC was assessed by [$^3H$]digoxin accumulation in the LLCPK1-MDR1 cell system. TSAHC strongly inhibited CYP2C8, CYP2C9, and CYP2C19 isoform activities with $K_i$ values of 0.81, 0.076, and $3.45{\mu}M$, respectively. It also enhanced digoxin accumulation in a dose-dependent manner in the LLCPK1-MDR1 cells. These findings indicate that TSAHC has the potential to inhibit CYP2C isoforms and P-gp activities in vitro. TSAHC might be used as a nonspecific inhibitor of CYP2C isoforms based on its negligible inhibitory effect on other P450 isoforms such as CYP1A2, CYP2A6, CYP2B6, CYP2D6, CYP2E1, and CYP3A.

• Korean journal of applied entomology
• /
• v.51 no.1
• /
• pp.47-58
• /
• 2012

Effect of a new crop protectant 'Bt-Plus' on natural enemies was analyzed in this study. Tested natural enemies included two parasitic species of $Aphidius$ $colemani$ and $Eretmocerus$ $eremicus$, and four predatory species of $Harmonia$ $axyridis$, $Orius$ $laevigatus$, $Amblyseius$ $swirskii$, and $Phytoseiulus$ $persimilis$. 'Bt-Plus' was formulated by combination of three entomopathogenic bacteria ($Xenorhabdus$ $nematophila$ (Xn), $Photorhabdus$ $temperata$ subsp. $temperata$ (Ptt), $Bacillus$ $thuringiensis$ (Bt)) and bacterial metabolite (BM). All three types of 'Bt-Plus' showed significantly higher toxicities against fourth instar $Plutella$ $xylostella$ larvae than Bt single treatment. Two types of bacterial mixtures ('Xn+Bt' and 'Ptt+Bt') showed little toxicity to all natural enemies in both contact and oral feeding assays. However, 'BM+Bt' showed significant toxicities especially to two predatory mites of $A.$ $swirskii$ and $P.$ $persimilis$. The acaricidal effects of different bacterial metabolites were evaluated against two spotted spider mite, $Tetranychus$ $urticae$. All six BM chemicals showed significant acaricidal effects. The BM mixture used to prepare 'Bt-Plus' showed a high acaricidal activity with a median lethal concentration at 218.7 ppm (95% confidence interval: 163.2 - 262.3). These toxic effects of bacterial metabolites were also proved by cytotoxicity test against Sf9 cells. Especially, benzylideneacetone, which was used as a main ingredient of 'BM+Bt', showed high cytotoxicity at its low micromolar concentration.

• Korean Journal of Veterinary Research
• /
• v.42 no.1
• /
• pp.89-100
• /
• 2002

The nonstructural glycoprotein NSP4, encoded by the 10th gene of rotavirus, has been known to play important roles in viral assembly and pathogenesis. The NSP4 genes of human rotavirus Korean isolates, designated as CBNU/HR-1, CBNU/HR-2, CBNU/HR-3, and CBNU/HR-4, were cloned, sequenced and characterized. Also, the NSP4 gene of the CBNU/HR-1 was expressed in a baculovirus-insect cell system. The sequence data indicated that the NSP4 genes of human rotavirus Korean isolates were 750 or 751 bases in length and encoded one open reading frame of 175 amino acids. Two glycosylation sites were recognized in the NSP4 gene of human rotavirus isolates tested. The NSP4 of CBNU/HR-1, CBNU/HR-3, and CBNU/HR-4 exhibited a high degree of amino acid sequence homology with that of NSP4 genotype B viruses, but a low degree of amino acid sequence homology with that of NSP4 genotype A viruses. However, the NSP4 of CBNU/HR-2 exhibited a high degree of amino acid sequence homology with that of NSP4 genotype A viruses, but a low degree of amino acid sequence homology with that of NSP4 genotype B viruses. The Sf9 cells infected with recombinant baculovirus, inserted with NSP4 gene of CBNU/HR-1, produced specific cytopathic effects and the expressed NSP4 was detected by immunofluorescence staining using NSP4-specific monoclonal antibody(MAb). The expressed NSP4 migrated at 16-26 kDa on SDS-PAGE and reacted with NSP4-specific MAb by Western blotting.