Influence of the Safener Benoxacor on the Metabolism of Metolachlor in Corn

1991 ◽  
Vol 46 (9-10) ◽  
pp. 846-849 ◽  
Author(s):  
C. K. Cottingham ◽  
K. K. Hatzios
Keyword(s):  
Mechanism Of Action ◽  
Dose Response ◽  
Similar Degree ◽  
Glutathione S Transferase ◽  
Corn Hybrids ◽  
Polar Metabolite ◽  
Herbicide Safener ◽  
Low Concentrations ◽  
Gst Activity ◽  
Corn Hybrid

Abstract The herbicide safener benoxacor (CGA -154281) is effective in protecting corn from meto­lachlor injury. Glutathione-S-transferase (GST) activity of corn seedlings was stimulated by low concentrations of benoxacor as was the formation of a polar metabolite identified as the glutathione (GSH) conjugate of metolachlor. A similar degree of enhancement of metolachlor metabolism was observed in both a metolachlor-tolerant (’Cargill 7567’) and a metolachlor-susceptible (’Northrup-King 9283’) corn line. The total GSH content of shoots of the metolachlor-susceptible corn hybrid was not affected by benoxacor treatment, but an increase was noted for shoots of the tolerant corn hybrid. The two corn hybrids with differential tolerance to metolachlor also differ in their dose response to benoxacor with higher safener concentra­tions failing to induce or inhibit GST activity of the tolerant ’Cargill 7567’ corn line. Stimula­tion of GST activity and a corresponding enhanced rate of metolachlor metabolism can ac­count for the safening effect of benoxacor. These mechanism of action of dichloroacetamide safeners.

scholarly journals Toxicity of naphthalene in the Neotropical Fish Astyanax Lacustris (Characiformes: Characidae) and Geophagus Brasiliensis (Perciformes: Cichlidae)

2017 ◽  
Vol 17 (1) ◽  
pp. 7-22 ◽  
Author(s):  
Geonildo Rodrigo Disner ◽  
Sabrina Louise Moraes Calado ◽  
Helena Cristina Silva Assis ◽  
Marta Margarete Cestari
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Micronucleus Test ◽  
Glutathione S Transferase ◽  
Neotropical Fish ◽  
Compensatory Response ◽  
Low Concentrations ◽  
Geophagus Brasiliensis ◽  
Polycyclic Aromatic ◽  
Gst Activity

Polycyclic aromatic hydrocarbons are one of the most important organic pollutants in environmental studies. The aim of this study was to assess the naphthalene acute toxicity in two fish species, Astyanax lacustris (LLcust, 1875) and Geophagus brasiliensis (Quoy & Gaimard, 1824). The fish were exposed to naphthalene (0.005, 0.03, 0.3, and 3 mgL-1) in water and after that the piscine micronucleus test in erythrocytes, comet assay in blood, liver and gill cells, glutathione S–transferase (GST) activity in the liver, and accumulation of naphthalene in the bile were performed. The susceptibility of the two species was similar and naphthalene was not genotoxic in all tested tissues. The liver GST activity may have been responsible for less damage observed in the liver while the highest DNA damage occurred in blood cells. However, low concentrations of naphthalene in water can stimulate apparent benefits, such as less DNA damage, which would be a compensatory response to an imbalance of homeostasis. The naphthalene is absorbed and can accumulate in the gall bladder, a greater accumulation of PAH was observed in A. lacustris, while G. brasiliensis did not differ from the control. The naphthalene concentrations are not genotoxic to the tested species, although they can potentially accumulate into the body.Keywords: Comet assay. Ecotoxicology. Fish. Genotoxicity. Hormesis.

Induction of Maize Glutathione S-Transferase by Herbicide Safener and their Effect on Enzyme Activity against Chlorsulfuron

2012 ◽  
Vol 518-523 ◽  
pp. 5480-5483 ◽  
Author(s):  
Li Xia Zhao ◽  
Cheng Guo Liu ◽  
Ying Fu ◽  
Zhi Yong Xing ◽  
Fei Ye ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Recovery Rate ◽  
Acetolactate Synthase ◽  
Kinetic Constants ◽  
Glutathione S Transferase ◽  
Chiral Compound ◽  
Herbicide Safener ◽  
Gst Activity

The acetolactate synthase(ALS) activity, glutathione S-transferase(GST) activity and glutathione(GSH) content in maize was investigated in response to treatments with safener (S)-3-dichloroacetyl-2,2-dimethyl-4-ethyl-1,3-oxazolidine. When induced by the chiral compound, the GSH content in root and shoot of maize increased 91.10% and 71.66%, respectively, the recovery rate of ALS activity reached 77%, and the GST activity increased 103.77%. The activity of maize GST was also assayed towards chlorsulfuron in vitro; the results showed that the induction of GST activity against chlorsulfuron of 14.54% was obtained. The enhancement of GST activity was found to be concomitant with changes in kinetic constants, which was related directly to the enzyme affinity for the CDNB substrate.

scholarly journals Effects of three pesticides on superoxide dismutase and glutathione-S-transferase activities and reproduction of Daphnia magna

2017 ◽  
Vol 43 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Yuzhi Song ◽  
Mindong Chen ◽  
Junying Zhou
Keyword(s):  
Water Pollution ◽  
Superoxide Dismutase ◽  
Surface Runoff ◽  
Aquatic Organisms ◽  
Reproductive Parameters ◽  
Glutathione S Transferase ◽  
Sod Activity ◽  
Low Concentrations ◽  
Total Fecundity ◽  
Gst Activity

Abstract Applying pesticides to crops is one of the causes of water pollution by surface runoff, and chlorpyrifos, trifluralin and chlorothalonil are used respectively as insecticide, herbicide and fungicide for crop plants widely. To explore effects of three pesticides on aquatic organisms, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities were determined after 24 h and 48 h exposure of D. magna with ages of 6–24 h to several low concentrations of chlorpyrifos (0.36, 0.72, 1.43, 2.86, 5.72 μg∙L−1), trifluralin (0.17, 0.33, 0.66, 1.33, 2.65 mg∙L−1) and chlorothalonil (0.09, 0.18, 0.36, 0.72, 1.43 mg∙L−1) respectively. Main reproductive parameters including first pregnancy time, first brood time, the number of first brood and total fecundity after 21 d exposures at the same concentrations of pesticides as described above were also measured. The results showed that the activities of GST increased in lower concentrations and decreased in higher concentrations after 24 h exposure to three pesticides, respectively. The activities of SOD showed the same changes after 48 h exposure. With the time prolonged, the activities of GST decreased while the activities of SOD increased. After 21 d exposure, the first pregnancy time and first brood time were delayed, while the number of the first brood and total fecundity per female decreased with increasing concentrations. These results corroborated that GST activity was more sensitive to those pesticides than SOD activity, and there was a significant relationship between total fecundity and pesticides-dose(r>0.94, n=6), GST activity after 48 h exposure and total fecundity after 21 d exposure (r>0.92, n=6).

Chemoprotective Effects of Propolis on Aflatoxin B1-Induced Hepatotoxicity in Rats: Oxidative Damage and Hepatotoxicity by Modulating TP53, Oxidative Stress

2020 ◽  
Vol 17 (3) ◽  
pp. 191-199
Author(s):  
Seval Yilmaz ◽  
Fatih Mehmet Kandemir ◽  
Emre Kaya ◽  
Mustafa Ozkaraca
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Oxidative Damage ◽  
Aflatoxin B1 ◽  
Tp53 Gene ◽  
Control Group ◽  
Glutathione S Transferase ◽  
Gene Expressions ◽  
Cat Gene ◽  
Gst Activity

Objective: This study aimed to detect hepatic oxidative damage caused by aflatoxin B1 (AFB1), as well as to examine how propolis protects against hepatotoxic effects of AFB1. Method: Rats were split into four groups as control group, AFB1 group, propolis group, AFB1+ propolis group. Results: There was significant increase in malondialdehyde (MDA) level and tumor suppressor protein (TP53) gene expression, Glutathione (GSH) level, Catalase (CAT) activity, CAT gene expression decreased in AFB1 group in blood. MDA level and Glutathione-S-Transferase (GST) activity, GST and TP53 gene expressions increased in AFB1 group, whereas GSH level and CAT activity alongside CAT gene expression decreased in liver. AFB1+propolis group showed significant decrease in MDA level, GST activity, TP53 and GST gene expressions, GSH level and CAT activity and CAT gene expression increased in liver compared to AFB1 group. Conclusion: These results suggest that propolis may potentially be natural agent that prevents AFB1- induced oxidative stress and hepatotoxicity.

scholarly journals Hormetic Concentrations of Hydrogen Peroxide but Not Ethanol Induce Cross-Adaptation to Different Stresses in Budding Yeast

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Halyna M. Semchyshyn
Keyword(s):  
Hydrogen Peroxide ◽  
Dose Response ◽  
Budding Yeast ◽  
Regulatory Protein ◽  
Colony Growth ◽  
Inhibitory Effect ◽  
Cross Resistance ◽  
Mild Stress ◽  
Low Concentrations ◽  
Cross Adaptation

The biphasic-dose response of microorganisms to hydrogen peroxide is a phenomenon of particular interest in hormesis research. In different animal models, the dose-response curve for ethanol is also nonlinear showing an inhibitory effect at high doses but a stimulatory effect at low doses. In this study, we observed the hormetic-dose response to ethanol in budding yeastS. cerevisiae. Cross-protection is a phenomenon in which exposure to mild stress results in the acquisition of cellular resistance to lethal stress induced by different factors. Since both hydrogen peroxide and ethanol at low concentrations were found to stimulate yeast colony growth, we evaluated the role of one substance in cell cross-adaptation to the other substance as well as some weak organic acid preservatives. This study demonstrates that, unlike ethanol, hydrogen peroxide at hormetic concentrations causes cross-resistance ofS. cerevisiaeto different stresses. The regulatory protein Yap1 plays an important role in the hormetic effects by low concentrations of either hydrogen peroxide or ethanol, and it is involved in the yeast cross-adaptation by low sublethal doses of hydrogen peroxide.

scholarly journals FEEDING VALUE OF SILAGE FROM A TILLERING AND A NONTILLERING HYBRID CORN

1975 ◽  
Vol 55 (4) ◽  
pp. 955-959 ◽  
Author(s):  
D. M. BOWDEN ◽  
N. B. McLAUGHLIN ◽  
S. FREYMAN
Keyword(s):  
Average Daily Gain ◽  
Average Weight ◽  
Corn Hybrids ◽  
Total Period ◽  
Whole Plant ◽  
Southern Alberta ◽  
Feeding Value ◽  
Daily Gain ◽  
Matter Energy ◽  
Corn Hybrid

Whole-plant silages made from a tillering corn hybrid (Zea mays L.) and a nontillering corn hybrid had similar digestibilities of dry matter, energy, and protein as assessed with wether sheep. When the silages were fed as the only feed for 56 days to yearling Hereford steers weighing an average of 370 kg, the intake of silage from the nontillering corn tended to be low and the steers only maintained their weight. Steers fed silage from the tillering corn gained 0.45 kg/day. However, with supplemental steamed, rolled barley being given for the remainder of the 112 days, average weight gains for the total period did not differ significantly (P < 0.05) between steers on the two silages. When barley was fed with each of the silages at 0.5% of body weight, the average daily gain of steers for 112 days was the same for the two silages (0.79 kg/day). The digestible energy consumed per unit of gain did not differ significantly (P < 0.05) between the two silages. We conclude that, when fed with a limited amount of barley, silages of equal feeding value could be made from tillering and nontillering corn hybrids grown in southern Alberta.

Immunoassay of low concentrations of albumin in urine by latex particle counting.

1988 ◽  
Vol 34 (2) ◽  
pp. 416-418 ◽  
Author(s):  
C L Cambiaso ◽  
D Collet-Cassart ◽  
M Lievens
Keyword(s):  
Detection Limit ◽  
Dose Response ◽  
Response Curve ◽  
Latex Particle ◽  
Urinary Albumin ◽  
Diagnostic Systems ◽  
Particle Counting ◽  
Low Concentrations ◽  
The Impact

Abstract We describe here a nonisotopic immunoassay, based on particle-counting technology, for the determination of urinary albumin. The assay takes only 35 min and has been fully automated on the IMPACT (Acade Diagnostic Systems, Brussels, Belgium) machine. The system measures albumin within a linear range between 6.25 and 50 mg/L and has a detection limit of 0.4 mg/L. Analytical recoveries at three concentrations ranged between 96% and 102%. Within-run precision ranged from 1.6% to 9.5%. The method was compared with a commercial nephelometric immunoassay system and a correlation coefficient of 0.996 was found for 216 urine samples. No antigen excess affects the shape of the curve in our system, whereas in nephelometry a 3 g/L solution of albumin starts to decrease the dose-response curve.

Improved herbicide selectivity in tomato by safening action of benoxacor and fenclorim

2020 ◽  
Vol 34 (5) ◽  
pp. 647-651
Author(s):  
Edicarlos Castro ◽  
Carolina Pucci ◽  
Stefano Duarte ◽  
Nilda Roma Burgos ◽  
Te Ming Tseng
Keyword(s):  
Seed Treatment ◽  
Mechanisms Of Action ◽  
Shoot Biomass ◽  
Glutathione S Transferase ◽  
Visible Injury ◽  
Factor B ◽  
Tomato Plants ◽  
Alternative Weed Control ◽  
Biomass Reduction ◽  
Gst Activity

AbstractSafeners have been widely used to reduce phytotoxicity to crops, thus serving as an alternative weed control strategy. Benoxacor and fenclorim safeners have the potential to protect plants from herbicide phytotoxicity by increasing glutathione S-transferase (GST) activity within the plant. The study aimed to evaluate the safening effect of benoxacor and fenclorim on tomato against selected herbicides applied POST. The experiment was conducted in a greenhouse in a completely randomized designed with four replications in a 9 × 3 factorial scheme, where Factor A consisted of eight herbicides including a nontreated control, and Factor B consisted of two safeners including a nontreated control. The herbicide treatments were sulfentrazone (0.220 kg ai ha−1), fomesafen (0.280 kg ai ha−1), flumioxazin (0.070 kg ai ha−1), linuron (1.200 kg ai ha−1), metribuzin (0.840 kg ai ha−1), pyroxasulfone (0.220 kg ai ha−1), and bicyclopyrone (0.040 kg ai ha−1). Safener treatments consisted of benoxacor (0.67 g L−1) and fenclorim (10 µM). Tomato seeds were immersed in safener solution before sowing and herbicides were applied when tomato plants were at the 3-leaf stage, or 25 days after sowing. Visible injury was scored at 3, 7, 14, and 21 d after application (DAA), and shoot biomass was recorded 21 DAA. Seed treatment with fenclorim reduced injury caused by imazamox and bicyclopyrone by 5.5 and 1.3 times, respectively, whereas benoxacor reduced the injury from bicyclopyrone 1.3 times. In addition, tomato plants pretreated with fenclorim showed a lesser reduction in biomass after application of imazamox, fomesafen, and metribuzin, whereas plants pretreated with benoxacor showed lesser biomass reduction after metribuzin application. Thus, the use of safeners promotes greater crop selectivity, allowing the application of herbicides with different mechanisms of action on the crop.

Differential Butylate Injury to Corn Hybrids

Weed Science ◽  
1973 ◽  
Vol 21 (3) ◽  
pp. 194-196 ◽  
Author(s):  
T. H. Wright ◽  
C. E. Rieck
Keyword(s):  
Zea Mays ◽  
South Carolina ◽  
Field Experiments ◽  
Laboratory Studies ◽  
Corn Hybrids ◽  
Corn Hybrid

Injury to corn (Zea maysL.) fromS-ethyl diisobutylthiocarbamate (butylate) was investigated with respect to hybrid. Field experiments in 1971 at Dillon and Clemson, South Carolina, established that the corn hybrid ‘Coker 71’ was more tolerant to butylate than ‘Pioneer 511A’. Also established as being tolerant and sensitive to butylate were the hybrids ‘Pioneer 3030’ and ‘PAG 644’, respectively. Laboratory studies with14C-butylate showed that the resistant hybrid ‘Pioneer 3030’ took up less14C-butylate and metabolized more to14CO2than did ‘PAG 644’.

scholarly journals Confirmation of S-metolachlor resistance in Palmer amaranth (Amaranthus palmeri)

2019 ◽  
Vol 33 (5) ◽  
pp. 720-726 ◽  
Author(s):  
Chad Brabham ◽  
Jason K. Norsworthy ◽  
Michael M. Houston ◽  
Vijay K Varanasi ◽  
Tom Barber
Keyword(s):  
Dose Response ◽  
Resistance Mechanism ◽  
Acetolactate Synthase ◽  
Chain Fatty Acid ◽  
Palmer Amaranth ◽  
Cross Resistance ◽  
Amaranthus Palmeri ◽  
Glutathione S Transferase ◽  
Long Chain Fatty Acid ◽  
Long Chain

AbstractS-Metolachlor is commonly used by soybean and cotton growers, especially with POST treatments for overlapping residuals, to obtain season-long control of glyphosate- and acetolactate synthase (ALS)–resistant Palmer amaranth. In Crittenden County, AR, reports of Palmer amaranth escapes following S-metolachlor treatment were first noted at field sites near Crawfordsville and Marion in 2016. Field and greenhouse experiments were conducted to confirm S-metolachlor resistance and to test for cross-resistance to other very-long-chain fatty acid (VLCFA)–inhibiting herbicides in Palmer amaranth accessions from Crawfordsville and Marion. Palmer amaranth control in the field (soil <3% organic matter) 14 d after treatment (DAT) was ≥94% with a 1× rate of acetochlor (1,472 g ai ha–1; emulsifiable concentrate formulation) and dimethenamid-P (631 g ai ha–1). However, S-metolachlor at 1,064 g ai ha–1 provided only 76% control, which was not significantly different from the 1/2× and 1/4× rates of dimethenamid-P and acetochlor (66% to 85%). In the greenhouse, Palmer amaranth accessions from Marion and Crawfordsville were 9.8 and 8.3 times more resistant to S-metolachlor compared with two susceptible accessions based on LD50 values obtained from dose–response experiments. Two-thirds and 1.5 times S-metolachlor at 1,064 g ha–1 were the estimated rates required to obtain 90% mortality of the Crawfordsville and Marion accessions, respectively. Data collected from the field and greenhouse confirm that these accessions have evolved a low level of resistance to S-metolachlor. In an agar-based assay, the level of resistance in the Marion accession was significantly reduced in the presence of a glutathione S-transferase (GST) inhibitor, suggesting that GSTs are the probable resistance mechanism. With respect to other VLCFA-inhibiting herbicides, Marion and Crawfordsville accessions were not cross-resistant to acetochlor, dimethenamid-P, or pyroxasulfone. However, both accessions, based on LD50 values obtained from greenhouse dose–response experiments, exhibited reduced sensitivity (1.5- to 3.6-fold) to the tested VLCFA-inhibiting herbicides.

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