scholarly journals Protective Responses Induced by Chiral 3-Dichloroacetyl Oxazolidine Safeners in Maize (Zea mays L.) and the Detoxification Mechanism

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3060 ◽  
Author(s):  
Gao ◽  
Liu ◽  
Jiang ◽  
Fu ◽  
Zhao ◽  
...  

Herbicide safeners selectively protect crops from herbicide injury while maintaining the herbicidal effect on the target weed. To some extent, the detoxification of herbicides is related to the effect of herbicide safeners on the level and activity of herbicide target enzymes. In this work, the expression of the detoxifying enzyme glutathione S-transferase (GST) and antioxidant enzyme activities in maize seedlings were studied in the presence of three potential herbicide safeners: 3-dichloroacetyl oxazolidine and its two optical isomers. Further, the protective effect of chiral herbicide safeners on detoxifying chlorsulfuron in maize was evaluated. All safeners increased the expression levels of herbicide detoxifying enzymes, including GST, catalase (CAT), and peroxidase (POD) to reduce sulfonylurea herbicide phytotoxicity in maize seedlings. Our results indicate that the R-isomer of 3-(dichloroacetyl)-2,2,5-trimethyl-1,3-oxazolidine can induce glutathione (GSH) production, GST activity, and the ability of GST to react with the substrate 1-chloro-2,4-dinitrobenzene (CDNB) in maize, meaning that the R-isomer can protect maize from damage by chlorsulfuron. Information about antioxidative enzyme activity was obtained to determine the role of chiral safeners in overcoming the oxidative stress in maize attributed to herbicides. The interaction of safeners and active target sites of acetolactate synthase (ALS) was demonstrated by molecular docking modeling, which indicated that both isomers could form a good interaction with ALS. Our findings suggest that the detoxification mechanism of chiral safeners might involve the induction of the activity of herbicide detoxifying enzymes as well as the completion of the target active site between the safener and chlorsulfuron.

2016 ◽  
Vol 56 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Ibrahim Saleh Abdallah ◽  
Hala Mohamed Abou-Yousef ◽  
Eman Atef Fouad ◽  
Mohammed Abd El-Hady Kandil

Abstract The cowpea aphid (Aphis craccivora Koch) is considered a serious insect pest attacking several crops. We carried out biochemical studies to elucidate the role of the metabolising enzymes in conferring resistance to thiamethoxam, in two strains (resistant and susceptible) of the cowpea aphid. Bioassay experiments showed that the thiamethoxam selected strain developed a 48 fold resistance after consecutive selection with thiamethoxam for 12 generations. This resistant strain also exhibited cross-resistance to the tested carbamates; pirimicarb and carbosulfan, organophosphorus (malathion, fenitrothion, and chlorpyrifos-methyl), and the neonicotinoid (acetamiprid). Synergism studies have indicated that S,S,S-tributyl phosphorotrithioate (DEF), a known inhibitor for esterases, increased thiamethoxam toxicity 5.58 times in the resistant strain compared with the susceptible strain. Moreover, the biochemical determination revealed that carboxylestersae activity was 30 times greater in the resistant strain than in the susceptible strain. In addition, the enzyme activity of glutathione S-transferase (GST) and mixed function oxidases (mfo) increased only in the resistant strain 3.7 and 2.7 times, respectively, in relation to the susceptible (the control). Generally, our results suggest that the higher activity of the detoxifying enzymes, particularly carboxylesterase, in the resistant strain of the cowpea aphid, apparently have a significant role in endowing resistance to thiamethoxam, although additional mechanisms may contribute.


2015 ◽  
Vol 95 (5) ◽  
pp. 897-903 ◽  
Author(s):  
Li-Xia Zhao ◽  
Hai-Tao Qu ◽  
Ying Fu ◽  
Shuang Gao ◽  
Fei Ye

Zhao, L.-X., Qu, H.-T., Fu, Y., Gao, S. and Ye, F. 2015. Alleviation of injury from chlorimuron-ethyl in maize treated with safener 3-dichloroacetyl oxazolidine. Can. J. Plant Sci. 95: 897–903. The protective effects of herbicide safeners, including 3-dichloroacetyl-2,2-dimethyl-1,3-oxazolidine (R-28725), 3-dichloroacetyl-2,2-dimethyl-4-ethyl-1,3-oxazolidine (Racemate), and its two enantiomers (R)-3-dichloroacetyl-2,2-dimethyl-4-ethyl-1,3-oxazolidine (R-enantiomer) and (S)-3-dichloroacetyl-2,2-dimethyl-4-ethyl-1,3-oxazolidine (S-enantiomer), on reducing the phytotoxicity of chlorimuron-ethyl to maize were investigated. Soaking the seeds in safeners increased the endogenous glutathione (GSH) content and glutathione-S-transferase (GST) activity of maize. When induced by R-enantiomer, the GST activity in vivo and in vitro increased 180 and 192% compared with control, respectively. R-28725 and R-enantiomer also increased the acetolactate synthase (ALS) activity inhibited by chlorimuron-ethyl from 45 to 100 and 97% compared with the control, respectively. The kinetic parameter Vmax of GST in the maize treated with R-28725 and R-enantiomer increased by 103 and 92%, respectively, compared with the control. Our results suggest that R-28725 and R-enantiomer could significantly improve the GSH content, GST activity, and ALS activity of maize. Overall, maize could be protected from the injury caused by chlorimuron-ethyl.


2016 ◽  
Vol 56 (4) ◽  
pp. 346-352 ◽  
Author(s):  
Banakar Halappa ◽  
Rajashekar K. Patil

AbstractThe cotton leafhopper (Amrasca biguttula biguttula Ishida) is considered to be an alarming insect pest causing both quantitative and qualitative loss in cotton. In situ bioassay studies were done and the role of detoxifying enzymes in conferring resistance to neonicotinoid groups of insecticides in low (MUD), medium (DVG), high (HVR) and very high (GLB) pesticide usage areas of Karnataka were determined. Bioassay studies showed that imidacloprid, thiamethoxam, acetamiprid, thiacloprid and clothianidin registered varying levels of resistance for all the locations studied. The resistance ratio was high in imidacloprid (3.35, 8.57, 9.15 and 12.27 fold respectively) and the lowest in dinoferuran (1.86, 5.13, 6.71 and 9.88 fold respectively). Furthermore, the enzyme activity ratio (glutathione-S-transferase) was relatively greater, and corresponded to the higher LC50values of neonicotinoids for very high, high, medium and low pesticide usage areas. Our study suggested that the higher activity of the detoxifying enzyme in the resistance population of cotton leafhopper apparently has a significant role in endowing resistance to neonicotinoid groups of insecticides. However, this study recommends using neonicotinoids in cotton growing areas with caution.


1992 ◽  
Vol 262 (6) ◽  
pp. L748-L756 ◽  
Author(s):  
S. J. Sullivan ◽  
T. D. Oberley ◽  
R. J. Roberts ◽  
D. R. Spitz

HA-1 hamster fibroblasts receiving fresh media every 24 h were continuously passaged in progressively increasing O2 concentrations for 18 mo (designated O2R95). These cells were significantly more resistant than parental HA-1 to clonogenic inactivation mediated by 95% O2 without media replacement. The O2R95 cell line exhibited increases in the activities of catalase (CAT), Mn superoxide dismutase (MnSOD), Cu,Zn superoxide dismutase (Cu,Zn SOD), and glutathione peroxidase (GPx). O2R95 cells demonstrated uniformly distributed increased staining for CAT, MnSOD, Cu,Zn SOD, and GPx proteins, as determined by immunohistochemistry. Cellular resistance to and metabolism of 4-hydroxy-2-nonenal (4HNE), a toxic byproduct of lipid peroxidation implicated in mechanisms of O2 toxicity, was examined in HA-1 and O2R95 cell lines. O2R95 cells were significantly more resistant to 4HNE cytotoxicity, which was accompanied by a significant increase in 4HNE metabolism. O2R95 cells also demonstrated an increase in total glutathione (GSH) and glutathione S-transferase (GST) activity, an enzymatic system believed to be involved with 4HNE metabolism. Furthermore, homogenates from O2R95 cells consumed greater quantities of 4HNE in the presence of NADPH (but not NADH, NAD+, or NADP+), suggesting that an enzyme(s) utilizing NADPH contributes to 4HNE metabolism, resistance to 95% O2 and 4HNE as well as increased total GSH, antioxidant enzyme activities, and NADPH-dependent metabolism of 4HNE, persisted in O2R95 cells for 75 days of growth in 21% O2. These findings are compatible with the hypothesis that aldehydic byproducts of lipid peroxidation contribute to mechanisms of O2 toxicity and the selective pressure exerted by exposure of cells to hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS).


Author(s):  
Sangeethadevi Govindasami ◽  
Veera Venkata Sathibabu Uddandrao ◽  
Nivedha Raveendran ◽  
Vadivukkarasi Sasikumar

Background: This study determined the effect of Biochanin A (BCA) on isoproterenol (ISO) induced Myocardial Infarction (MI) in male Wistar rats. Methods: Animals (weighing 150-180 g) were divided into four groups, with six animals in each group and pretreated with BCA (10mg/kg Body Weight [BW]) and ɑ-tocopherol (60mg/kg BW) for 30 days; and ISO (20mg/kg BW) was administrated subcutaneously on the 31st and 32nd day. Results: ISO-induced MI rats demonstrated the significant elevation of serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, lactate dehydrogenase, creatine kinase-MB and cardiac troponin; however, concomitant pretreatment with BCA protected the rats from cardiotoxicity caused by ISO. Activities of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase significantly reduced in the heart with ISO-induced MI. Pretreatment with BCA produced a marked reversal of these antioxidant enzymes related to MI-induced by ISO. Conclusion: In conclusion, this study suggested that BCA exerts cardioprotective effects through modulating lipid peroxidation, enhancing antioxidants, and detoxifying enzyme systems.


2021 ◽  
Author(s):  
Romina Frare ◽  
Cecilia Pascuan ◽  
Luisa Galindo-Sotomonte ◽  
Wayne McCormick ◽  
Gabriela Soto ◽  
...  
Keyword(s):  

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 649
Author(s):  
Marco Capolupo ◽  
Paola Valbonesi ◽  
Elena Fabbri

The ocean contamination caused by micro- and nano-sized plastics is a matter of increasing concern regarding their potential effects on marine organisms. This study compared the effects of a 21-day exposure to 1.5, 15, and 150 ng/L of polystyrene microplastics (PS-MP, 3-µm) and nanoplastics (PS-NP, 50-nm) on a suite of biomarkers measured in the Mediterranean mussel Mytilus galloprovincialis. Endpoints encompassed immunological/lysosomal responses, oxidative stress/detoxification parameters, and neurotoxicological markers. Compared to PS-MP, PS-NP induced higher effects on lysosomal parameters of general stress. Exposures to both particle sizes increased lipid peroxidation and catalase activity in gills; PS-NP elicited greater effects on the phase-II metabolism enzyme glutathione S-transferase and on lysozyme activity, while only PS-MP inhibited the hemocyte phagocytosis, suggesting a major role of PS particle size in modulating immunological/detoxification pathways. A decreased acetylcholinesterase activity was induced by PS-NP, indicating their potential to impair neurological functions in mussels. Biomarker data integration in the Mussel Expert System identified an overall greater health status alteration in mussels exposed to PS-NP compared to PS-MP. This study shows that increasing concentrations of nanoplastics may induce higher effects than microplastics on the mussel’s lysosomal, metabolic, and neurological functions, eventually resulting in a greater impact on their overall fitness.


1995 ◽  
Vol 268 (1) ◽  
pp. H278-H287 ◽  
Author(s):  
S. J. Elliott ◽  
T. N. Doan ◽  
P. N. Henschke

Oxidant stress mediated by tert-butyl hydroperoxide (t-BOOH) inhibits agonist-stimulated Ca2+ entry and internal store Ca2+ release in cultured endothelial cells. The role of intracellular glutathione in modulating the effects of oxidant stress on Ca2+ signaling was determined in cells preincubated with buthionine-[S,R]-sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, or 1-chloro-2,4-dinitrobenzene (CDNB), a cosubstrate for glutathione-S-transferase. BSO and CDNB decreased endothelial cell glutathione content by 85 and 97%, respectively (control glutathione, 21.5 +/- 2.3 nmol/mg protein). Each agent accelerated the time-dependent effects of t-BOOH on Ca2+ signaling in fura 2-loaded cells and potentiated the inhibition of bradykinin-stimulated 45Ca2+ efflux induced by t-BOOH. These results indicate that decreased availability of reduced glutathione, the primary cosubstrate for glutathione peroxidase, potentiates the effect of hydroperoxide oxidant stress on receptor-operated Ca2+ entry across the plasmalemma and Ca2+ release from internal stores. The present findings suggest that intracellular glutathione availability and/or glutathione redox cycle activity are critically important modulators of oxidant inhibition of Ca(2+)-dependent signal transduction.


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