• BMB Reports
• /
• v.30 no.1
• /
• pp.13-17
• /
• 1997

The inhibitory effect of herbicides such as sulfonylurea derivatives, imidazolinones and pyrimidylsalicylate has been examined on the purified valine sensitive acetolactate synthase (ALS) from Serratia marcescens. The concentration of sulfometuron methyl which inhibits 50% of the ALS activity was 2.5 mM. The required concentrations of triasulfuron, primisulfuron methyl and imazaquin for the 50% inhibition of the ALS activity were 1 mM. The resistance of Serratia ALS to sulfometuron methyl, imazapyr and imazaquin is similar to that of E. coli ALS 1. However, pyrimidylsalicylate showed a potent inhibitory effect on the Serratia ALS almost 13 times more potent than on E. coli ALS II, which is known as herbicide-sensitive isozyme. The inhibitory mode was competitive against pyruvate. 150 value was determined to be $17{\mu}M$ in an assay mixture containing 20 mM pyruvate, and the $K_1$, value was calculated to be $0.4{\mu}m$ from the modified double reciprocal plot of 1/V versus $1/S^2$.

• BMB Reports
• /
• v.31 no.1
• /
• pp.37-43
• /
• 1998

The catabolic ${\alpha}$-acetolactate synthase was purified to homogeneity from Serratia marcescens ATCC 25419 using ammonium sulfate fractionation, DEAE-Sepharose, Phenyl-Sepharose, and Hydroxylapatite column chromatography. The native molecular weight of the enzyme was approximately 150 kDa and composed of two identical subunits with molecular weights of 64 kDa each. The N-terminal amino acid sequence of the enzyme was determined to be Ala-Gln-Glu-Lys-Thr-Gly-Asn-Asp-Trp-Gln-His-Gly-Ala-Asp-Leu-Val-Val-Lys-Asn-Leu. It was not inhibited by the branched chain amino acids and sulfometuron methyl herbicide. The optimum pH of the enzyme was around pH 5.5 and the pI value was 6.1. The catabolic ${\alpha}$-acetolactate synthase showed weak immunological relationships with recombinant tobacco ALS, barley ALS, and the valine-sensitive ALS isozyme from Serratia marcescens.

• BMB Reports
• /
• v.40 no.4
• /
• pp.511-516
• /
• 2007

A glutathione S-transferase (GST) related to the phi (F) class of enzymes only found in plants has been cloned from the Oryza sativa. The GST cDNA was cloned by PCR using oligonucleotide primers based on the OsGSTF5 (GenBank Accession No. $\underline{AF309382}$) sequences. The cDNA was composed of a 669-bp open reading frame encoding for 223 amino acids. The deduced peptide of this gene shared on overall identity of 75% with other known phi class GST sequences. On the other hands, the OsGSTF5 sequence showed only 34% identity with the sequence of the OsGSTF3 cloned by our previous study (Cho et al., 2005). This gene was expressed in Escherichia coli with the pET vector system and the gene product was purified to homogeneity by GSH-Sepharose affinity column chromatography. The expressed OsGSTF5 formed a homo-dimer composed of 28 kDa subunit and its pI value was approximately 7.8. The expressed OsGSTF5 displayed glutathione conjugation activity toward 1-chloro-2,4-dinitrobenzene and 1,2-epoxy-3-(p-nitrophenoxy)propane and glutathione peroxidase activity toward cumene hydroperoxide. The OsGSTF5 also had high activities towards the herbicides alachlor, atrazine and metolachlor. The OsGSTF5 was highly sensitive to inhibition by S-hexylGSH, benastatin A and hematin. We propose from these results that the expressed OsGSTF5 is a phi class GST and appears to play a role in the conjugation of herbicide and GPOX activity.

• Korean Journal of Weed Science
• /
• v.14 no.4
• /
• pp.291-297
• /
• 1994

Seedlings of eight varieties of tomato were treated on the soil surface by each six application rate (0 to 5g ai/ha) of herbicide quinclorac. Percent of control in plant height at 7 days after treatment ranged from 69% to 81% at 5g ai/ha application of quinclorac. At 28 days after treatment those of (2-26)*836038 and (TR*VC8-1)-1-2F4 were 88% and 89%, respectively. However, those of other six varieties except former two varieties were 61% to 68%. The variations of percent of control in shoot dry weight among eight varieties were larger than those in plant height. Those of (2-26)*836038 and (TR*VC8-1)-1-2F4 were also higher than those of other six varieties at 4 - 5g ai/ha application of quinclorac.

• Korean Journal of Weed Science
• /
• v.16 no.2
• /
• pp.140-149
• /
• 1996

Three hundred rice(Oryza sativa L.) cultivars were screened for tolerance to butachlor [N-(buthoxymethyl)-2-chloro-N-(2,6-diethylphenyl) acetamide], thiobencarb(S-[(4-chlorophenyl)methyl]diethylcarbamothioate), and simetryn [N,N-diethyl-6-(methylthio)-1,3,5-triazine-2,4-diamine]. The responses of the rice cultivars to herbicides differed depending upon the herbicides and their concentrations. New Sabarmati(BAS), Gora, PTB 18 were tolerant to butachlor, and Azucena, IR44707-31-1-3-2, ARC 7293 to thiobencarb, while Gora, ARC 7293, and Dudmona were tolerant to both herbicides. Response of rice to simetryn differed from its response to butachlor and thiobencarb. Inhibition of shoot growth and fresh weight increased as the temperature and herbicide concentration increased. There was a higher correlation among rice cultivars response to butachlor and thiobencarb in the greenhouse when laboratory studies were conducted at higher temperatures.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.4
• /
• pp.501-505
• /
• 1996

Azimsulfuron [1H-pyrazole-5-sulfonamide,N-(((4,6-dimethoxy-pyridine-2-yl-aminocarbonyl-4-(2-methyl-2H-tetrazole-5-yl)] is a new sulfonamide herbicide that selectively controls a wide range of weeds in lowland rice (Oryza sativa). It effectively controlled Cyperus serotinus, Eleocharis kuroguwai, Sagittaria pygmaea, S. trifolia, and Scirpus juncoides at 7.5 - 30 g ai/ha. In the tolerance test on grasses carried out in a nutrient solution containing 0.3 - 30 ppm of azimsulfuron, greater inhibition occurred in roots of both rice and barnyardgrass (Echinochloa crus galli) than in shoots. However, rice root was approximately 5-fold more tolerant than that of barnyardgrass. The downward movements as determined by 50% growth inhibition of S. juncoides were 4-cm in clay loam and 6.5-cm in sandy loam soil with 3-cm/day leaching for 3 days. When incubated at 20 and $30^{\circ}C$, the residual effect in clay loam soil lasted for 30 and 21 days, respectively. In a soil column applied at 15 g ai/ha of azimsulfuron followed by 3-cm/day leaching for 3 days, dry weights of S. trifolia emerging at 5, 10, and 15-cm depth were reduced to 87, 85, and 79% of the corresponding untreated control, respectively. Susceptibility of S. trifolia to azimsulfuron did not greatly vary with the emergence depth.

• Korean Journal of Weed Science
• /
• v.16 no.4
• /
• pp.337-345
• /
• 1996

This study was conducted to investigate the protox activity, the PPIX accumulation and the activity of antioxidative enzymes of the oxyfluorfen-tolerant and -susceptible rice cultivars by oxyfluorfen and oxytluorfen-similar herbicides treatment. When treated with acifluorfen, bifenox or oxadiazon, the oxyfluorfen-tolerant rice cultivars showed less decreased in fresh weight than the susceptible rice cultivars. The inhibition of protox activity was in the order of acifluorfen > oxyfluorfen > bifenox > oxadiazon, and the PPIX accumulation was in the sequence of oxadiazon > acifluorfen > oxyfluorfen > bifenox. The inhibition of protox activity and the PPIX accumulation by the herbicide was greater in the susceptible rice cultivars than in the tolerant rice cultivars. The effect inhibiting the decrease of chlorophyll content resulting from the treatment of GC, tetrapyrrole biosynthesis inhibitor, was in the order of oxyfluorfen > acifluorfen > bifenox > oxadiazon, and the tolerant rice cultivar had more than the susceptible rice cultivar. In the treatment of DPE and oxadiazon, the activities of MDAR, POX and GR was higher in the tolerant rice cultivar than in the susceptible rice cultivar, and in the case of POX isozyme the activities of main D and E bands increased in the tolerant rice cultivars at tested herbicides but they didn't in the susceptible rice cultivar.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.1
• /
• pp.67-71
• /
• 1997

This experiment was conducted to test the allelopatic activity on germination and early seedling growth of weed species by barley and sorghum plants residues. The fresh barley extraction inhibited the germination and early seedling growth of weeds, Echinochloa crus-galli, Sataria viridis, and P. oleracea. As the extract concentration increased, the germination and early seedling growth of weeds was significantly inhibited. The water extraction of dried barley and sorghum residues also ehibited the strong inhibition effect on germination and Barley seedling growth of weeds. Digitaria sanguinalis, Siegesbechia pubescens, Sectaria viridis, P. oleracea, E. crus-galli. In the dried barley and sorghum residues mixture into the vermiculite, as the dried residue concentration ncreased, emergence percentage, length of shoot and root of weeds, D. saguinalis, S. viridis, S. pubescens, Ammaranthus lividus, and Solanum nigrum, was significantly inhibited. More than 10% concentration of dired residue caused 80% emergence percentage and growth inhibition. From this study, we conclude that barley and sorghym weeds. These results suggest that barley and sorghum has some possibility to control some weed species like natural herbicide.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.99-103
• /
• 1998

Triazolopyrimidine sulfonanilide (TP) derivative is one of excellent herbicide compounds. We have synthesized three classes of a new sulfonamide derivative (TPP) as Acetolactate synthase (ALS) inhibitors, in which the benzene ring in TP skeleton was converted to substituted pyrimidyl ring and examined their inhibitory activities on barley for ALS. $I_{50}$ values of the inhibitors ranged from 0.005 to 2 mM. Comparing the $I_{50}$ value of each class of TPP derivatives, the substituents in pyrimidine and triazolopyrimidine ring were found to affect the degree of ALS inhibition. TPP with substituted methyl group in pyrimidine ring showed higher inhibitory activity than that with methoxy group, while the substitution of the cyclopentano group in triazolopyrimidine ring gave very large inhibitory activity than that of methyl group. The present study established that variation of the electron density by substitution at heterocyclic ring is a very important factor for ALS inhibition, but showed no dependence on steric effect by substituents.

• Applied Biological Chemistry
• /
• v.38 no.4
• /
• pp.283-288
• /
• 1995

This study was carried out to investigate the toxic action of herbicide, paraquat(1,1'-dimethyl-4,4'-bipyridylium-dichloride), against microorganisms. The toxic effect of paraquat was observed mainly using Escherichia coli(KCTC 1039), as follows; Growth of aerobic microorganisms which comprise 4 strains of bacteria and 2 strains of yeast and 4 strains of mold was inhibited drastically in the presence of 1.0mM paraquat But the growth of anaerobic bacteria was not affected by the chemical. When actively growing cells of E. coli were exposed to the paraquat at the concentration higher than 1.0 mM, they rapidly lost their ability to form colony and clearly formed inhibitory zone by well test More than 50% of the cells were killed by 1.0 mM paraquat treatment, even at immediate addition of paraquat to the medium.