• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.331-336
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• 2016

Analytical methods for methiozolin in soil, water and turfgrass were established and dissipation patterns of methiozolin in soil and turfgrass were elucidated. Analysis was done using a high performance liquid chromatography with an ultra violet detector at the wavelength of 280 nm after extraction with acetone, liquid-liquid partition with dichloromethane, and a solid phase extraction purification. Limit of determination and Limit of quantitation were 1.0, 0.5, 1.0 ng, and 0.001, 0.1, 0.01 mg/kg for water, turfgrass, and soil, respectively. Recovery rates of methiozolin from soil, water, and turfgrass were ranged 87.5~111.3, 92.8~97.4, and 78.2~98.5 %, respectively. The turfgrass and soil samples were collected at 0, 1, 4, 7, 14, 30, 45, and 60 after spray on green area in golf course. Residues of methiozlolin were not translocated to lower soil layer but detected only in turfgrasses and root area of turfgrass. Half-lives of methiozolin in turfgrass were 10.7 days and 8.8 days in soil from root area.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.315-321
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• 2012

Fate of acetamiprid and imidacloprid aerially sprayed to control pine wood nematode (Bursaphelenchus xylophilus) were studied in a forest of Haman area. Acetamiprid 20% SL or imidacloprid 20% DC were diluted 100 times and applied two times as rate of 50 L/ha using an aircraft of Bell 206 L helicopter. Average acetamiprid deposits on forest floor ranged from 2 to 4% of standard aerial application rate. Following to the second application, acetamiprid deposits in the pine needle ranged 1.8~8.5 mg/kg and then gradually decreased to 1.2~2.1 mg/kg after 48 days. Deposits on the plant washed off by rainfall and reached to soil surface was ca. 17% of the application rate. All of acetamiprid on the ground resided in the forest floor covering the soil surface, where acetamiprid residues were decreased to a quarter at 48 days after the second application, but they were not detected in soil beneath it. And the only low level of acetamiprid residues, 0.0003 mg/L, was detected in the reservoir nearby the experimental forest on the day of aerial application. The acetamiprid detection was presumably due to spray drift. And average imidacloprid deposits on forest floor ranged from 1 to 3% of standard aerial application rate. Following to the second application, imidacloprid deposits in the pine needle analysed very low concentration of 0.1 mg/kg, but the amount of imidacloprid in wash-off in standard and two-fold treatment were ca. 8% and 4% of the application rate, respectively. Most of imidacloprid on the ground also resided in the forest floor, where imidacloprid residues were decreased to a twentieth at 111 days after the second application, and they were detected below 0.5% of the application rate in sol beneath it. And the low level of imidacloprid, 0.0003~0.0017 mg/L, were detected in the streams in the experimental forest. It was not to the level of contamination concerns.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.269-277
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• 2011

Recent outbreak of new diseases and pests which were introduced from abroad, seriously hampered both quality and safety of paprika fruits. This study has been carried out to aid an establishment of guideline for safe use of pesticides and reduction of their residues on paprika. Systemic fungicides boscalid and pyraclostrobin of either mixed (a.i.; 13.6+6.8%) or single (a.i.; 47 and 18.8%, respectively) water dispersible granule formulation(WG) products were sprayed with recommended or double dosage on paprika grown in green house at March and June. To draw pre-harvest residue limit, residues of each fungicide were analyzed from fruits collected eight times from 18 to 1 day pre-harvest. The biological half-lives of both boscalid and pyraclostrobin in mixed formulation in March and June were slightly shorter than those of single formulation which ranged from 14.4 to 20.1 days. Residue levels of both fungicides of single formulation in fruits in June were about one lower compared to those in March. However, application of double dosage frequently exceeded MRLs from fruits grown both seasons. These results showed that residue levels on fruits persisted longer period of time, more than two weeks, and so the case applied in winter season. The dissipation of fungicides on leaves and fruits was compared. The distribution of both fungicides in leaves was 20-200 times higher than that of fruits and persisted up to 18 days of pre-harvest period at the concentration of 10-40 ${\mu}g\;g^{-1}$. This study indicated that the mixed formulation product exhibited low residues in fruits, but high and long enough to pathogen growth in leaves.

• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.3.1-3.6
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• 2009

Introduction: GTPases known as translation factor play a vital role as ribosomal subunit assembly chaperone. The bacterial Obg proteins ($Spo{\underline{0B}}$-associated ${\underline{G}}TP$-binding protein) belong to the subfamily of P-loop GTPase proteins and now it is considered as one of the new target for antibacterial drug. The majority of bacterial Obgs have been commonly found to be associated with ribosome, implying that these proteins may play a fundamental role in ribosome assembly or maturation. In addition, one of the experimental evidences suggested that Bacillus subtilis Obg (BsObg) protein binds to the L13 ribosomal protein (BsL13) which is known to be one of the early assembly proteins of the 50S ribosomal subunit in Escherichia coli. In order to investigate binding mode between the BsObg and the BsL13, protein-protein docking simulation was carried out after generating 3D structure of the BsL13 structure using homology modeling method. Materials and Methods: Homology model structure of BsL13 was generated using the EcL13 crystal structure as a template. Protein-protein docking of BsObg protein with ribosomal protein BsL13 was performed by DOT, a macro-molecular docking software, in order to predict a reasonable binding mode. The solvated energy minimization calculation of the docked conformation was carried out to refine the structure. Results and Discussion: The possible binding conformation of BsL13 along with activated Obg fold in BsObg was predicted by computational docking study. The final structure is obtained from the solvated energy minimization. From the analysis, three important H-bond interactions between the Obg fold and the L13 were detected: Obg:Tyr27-L13:Glu32, Obg:Asn76-L13:Glu139, and Obg:Ala136-L13:Glu142. The interaction between the BsObg and BsL13 structures were also analyzed by electrostatic potential calculations to examine the interface surfaces. From the results, the key residues for hydrogen bonding and hydrophobic interaction between the two proteins were predicted. Conclusion and Prospects: In this study, we have focused on the binding mode of the BsObg protein with the ribosomal BsL13 protein. The interaction between the activated Obg and target protein was investigated with protein-protein docking calculations. The binding pattern can be further used as a base for structure-based drug design to find a novel antibacterial drug.

• BMB Reports
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• v.40 no.5
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• pp.791-800
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• 2007

Ethylene performs an important function in plant growth and development. 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), the key enzyme involved in ethylene biosynthesis, has been the focus of most ethylene studies. Here, a cotton ACS gene referred to as Gossypium hirsutum ACS1 (GhACS1), was isolated. The full-length cDNA of GhACS1 encodes for a 476-amino acid protein which harbors seven conserved regions, 11 invariant amino acid residues, and the PLP binding active site, all of which characterize ACC synthases. Alignment analysis showed that GhACS1 shared a high degree of identity with other known ACC synthases from different species. Two introns were detected in the genomic DNA sequence, and the results of Southern blot analysis suggested that there might be a multi-gene family encoding for ACC synthase in cotton. From the phylogenetic tree constructed with 24 different kinds of ACC synthases, we determined that GhACS1 falls into group II, and was closely associated with the wound-inducible ACS of citrus. The analysis of the 5' flanking region of GhACS1 revealed a group of putative cis-acting elements. The results of expression analysis showed that GhACS1 displayed its transient expression nature after wounding, abscisic acid (ABA), and $CuCl_2$ treatments. These results indicate that GhACS1, which was transiently expressed in response to certain stimuli, may be involved in the production of ethylene for the transmission of stress signals.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.270-275
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• 2005

Superoxide dismutases (SOD) are metalloenzymes that convert $O_2^-\;to\;H_2O_2$. Rehmannia glutinosa is highly tolerant to paraquat-induced oxidative stress. The primary objective of this study was to characterize regulation of SOD gene expression in R. glutinosa in response to oxidative stresses and hormones. A full-length putative SOD clone (RgCu-ZnSOD1) was isolated from the leaf cDNA library of R. glutinosa using an expressed sequence tag clone as a probe. RgCu-ZnSOD1 cDNA is 777 bp in length and contains an open reading frame for a polypeptide consisted of 152 amino acid residues. The deduced amino acid sequence of the clone shows highest sequence similarity to the cytosolic Cu-ZnSODs. The two to three major bands with several minor ones on the Southern blots indicate that RgCu-ZnSOD1 is a member of a small multi-gene family. RgCuZnSOD1 mRNA was constitutively expressed in the leaf, flower and root. The expression of RgCu-ZnSOD1 mRNA was increased about 20% by wounding and paraquat, but decreased over 50% by ethylene and $GA_3$. This result indicates that the RgCu-ZnSOD1 expression is regulated differentially by different stresses and phytohormones at the transcription level. The RgCu-ZnSOD1 sequence and information on its regulation will be useful in investigating the role of SOD in the paraquat tolerance of R. glutinosa.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.928-937
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• 2016

S-Nitrosoglutathione reductase (GSNOR) metabolizes S-nitrosoglutathione (GSNO) and has been shown to play important roles in regulating cellular signaling and formulating host defense by modulating intracellular nitric oxide levels. The enzyme has been found in bacterial, yeast, mushroom, plant, and mammalian cells. However, to date, there is still no evidence of its occurrence in filamentous fungi. In this study, we cloned and investigated a GSNOR-like enzyme from the filamentous fungus Aspergillus nidulans. The enzyme occurred in native form as a homodimer and exhibited low thermal stability. GSNO was an ideal substrate for the enzyme. The apparent K_m and k_cat values were 0.55 mM and 34,100 min^-1, respectively. Substrate binding sites and catalytic center amino acid residues based on those from known GSNORs were conserved in this enzyme, and the corresponding roles were verified using site-directed mutagenesis. Therefore, we demonstrated the presence of GSNOR in a filamentous fungus for the first time.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.230-260
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• 1992

The paper was reviewed the research results on weed dynamics and effective control methods in direct-seeded rice crop. Direct seeding method resulted in drastic increment of weed growth compared to transplanting method and also changed in troublesome weed flora. Two to three fold more weeds were harvested at the direct seeded rice and weed flora of dominant species shifted toward $C_4$type grass weeds. Some of the important troublesome weeds in direct seeded rice were Echinochloa crus-galle, Oryza saliva ssp spontanea, Leptochloa chinensis. Setaria viridus. Digitaria adsendens, Sesbania exaltata, Aeschynomene indica, Algae, etc. Yield loss due to weed competiton was about 40-60% for water-seeded and about 70-100% for dry-seeded rice while these for transplanted rice were about 25-35% for mechanical transplanting and about 10-20% for manual transplanting, respectively. Integrated weed management concept was neede to approach weed control effectively. Several cultural technologies were very effective to suppress the weed growth. These were tillage operation, water management, seeding date and seeding rate. Crop residues of barley, rice, wheat, oat and italian ryegrass were also effectivly suppressed the paddy weeds particularly to Potamogeton distiuctus, a perennial broadleaf weed. A pathogen of Epicoccosorus nematosporus identified from Eleocharis kuroguwai was an excellent potential bioagent to control the most troublesome perennial sedge weed of E. Kuroguwai without arising any detrimental effect. The herbicidal efficacy of this pathogen was as high as bentazon herbicide. Plant growth regulator of paclobutrazol (pp-333) was another possible alternative to reduce the herbicide use. In current, herbicide exhibited the most conspicuous results to control weeds in direct-seeded rice even though the application technologies were not fully established. Recommendations for herbicide application were suggested for in both water-and dry-seeded rice in USA, Japan and Korea, respectively. To make better and comprehensive recommendations further studies on weed ecology and herbicide development were emphasized.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.576-581
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• 2005

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. We have engineered the cell surface of the yeast. Saccharomyces cerevisiae, by anchoring active fungal phytase on its cell wall, in order to apply it as a dietary supplement containing bioconversional functions in animal foods and a whole cell bio-catalyst for the treatment of waste. The phytase gene (phyA) of Aspergillus niger with a signal peptide of rice amylase 1A (Ramy1A) was fused with the gene encoding the C-terminal half (320 amino acid residues from the C-terminus) of yeast ${\alpha}-agglutinin$, a protein which is involved in mating and is covalently anchored to the cell wall. The resulting fusion construct was introduced into S. cerevisiae and expressed under the control of the constitutive glyceraldehydes-3-phosphate dehydrogenase (GPD) promoter. Phytase plate assay revealed that the surface-engineered cell exhibited a catalytically active opaque zone which was restricted to the margin of the colony. Additionally, the phytase activity was detected in the cell fraction, but was not detected in the culture medium when it was grown in liquid. These results indicate that the phytase was successfully anchored to the cell surface of yeast and was displayed as its active form. The amount of recombinant phytase on the surface of yeast cells was estimated to be 16,000 molecules per cell.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.379-385
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• 2011

Ferulic acid esterase (FAE) and acetyl esterase (AE) cleave feruloyl groups substituted at the 5'-OH group of arabinosyl residues and acetyl groups substituted at O-2/O-3 of the xylan backbone, respectively, of arabinoxylans in the cell wall of grasses. In this study, the enzyme profiles of FAE, AE and polysaccharide hydrolases of the anaerobic rumen fungus Neocallimastix sp. YQ1 grown on Chinese wildrye grass hay (CW) or alfalfa hay (AH) were investigated by two $2{\times}4$ factorial experiments, each in 10-day pure cultures. The treatments consisted of two glucose levels ($G^+$: glucose at 1.0 g/L, $G^-$: no glucose) and four N sources (N1: 1.0 g/L yeast extract, 1.0 g/L tryptone and 0.5 g/L $(NH_4)_2SO_4$; N2: 2.8 g/L yeast extract and 0.5 g/L $(NH_4)_2SO_4$; N3: 1.6 g/L tryptone and 0.5 g/L $(NH_4)_2SO_4$; N4: 1.4 g/L tryptone and 1.7 g/L yeast extract) in defined media. The optimal combinations of glucose level and N source for the fungus on CW, instead of AH, were $G^-N4$ and $G^-N3$ for maximum production of FAE and AE, respectively. Xylanase activity peaked on day 4 and day 6 for the fungus grown on CW and AH, respectively. The activities of esterases were positively correlated with those of xylanase and carboxymethyl cellulase. The fungus grown on CW exhibited a greater volatile fatty acid production than on AH with a greater release of ferulic acid from plant cell wall.