scholarly journals Detoxifying enzyme studies on cotton leafhopper, Amrasca biguttula biguttula (Ishida), resistance to neonicotinoid insecticides in field populations in Karnataka, India

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.

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.


2013 ◽  
Vol 31 (3-6) ◽  
pp. 105-122 ◽  
Author(s):  
Min Tang ◽  
Simoni Triantafyllidou ◽  
Marc Edwards

AbstractWater leaks in distribution system mains and premise plumbing systems have very high costs and public health implications. The possible in situ remediation of leaks while a pipeline is in service could reduce leaking at costs orders of magnitude lower than conventional pipe repair, rehabilitation, or replacement. Experiences of Roman engineers and recent field observations suggest that such processes can occur naturally or may even be engineered to ameliorate leaks, including those caused by metallic corrosion. Three mechanisms of in situ leak remediation (i.e., metallic corrosion, physical clogging, and precipitation) are described in this paper, in an effort to understand the role of physical factors (e.g., temperature, pressure, and leak size) and water chemistry (e.g., pH, alkalinity, corrosion inhibitors, dissolved oxygen, and turbidity) in controlling in situ remediation for both inert (plastic and aged concrete) and chemically reactive (new concrete, copper, and iron) pipe materials. Although there are possible limitations and uncertainties with the phenomenon, including the fraction of pipeline leaks to which it might apply and the durability/longevity of remediation, such approaches may prove useful in economically sustaining some aging drinking water infrastructure assets and reducing future failure rates.


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.


Author(s):  
B.K. Cameron

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 259-261
Author(s):  
Aamir Khan ◽  
Rajni K. Gurmule

Vasavaleha is one of the best medicine given for respiratory diseases. Corona viruses typically affect the respiratory system, causing symptoms such as coughing, fever and shortness of breath. It also affects host immune system of human body. Spreading rate of this disease is very high. Whole world is seeking for the treatment which can uproots this diseases. There in no vaccine available till date against this pandemic disease. Ayurveda mainly focuses on prevention of diseases alongwith its total cure. Rajyakshma Vyadhi is MadhyamMarga Roga as per Ayurveda. It shows many symptoms such as Kasa, Shwasa etc. By overall view of Covid 19, shows its resemblance with Rajyakshma Vyadhi described in Ayurveda. Vasavaleha is a Kalpa which is described in Rogadhikara of Rajyakshma. It shows Kasahara, Shwashara properties. It consists of Vasa, Pipalli, Madhu and Goghrita. These components shows actions like bronchodilation, antitussive effect and many more other actions. Pipalli shows important Rasayana effect. So in present review, we have tried to focus on role of Vasavaleha in the management of Covid 19. This can be used as preventive as well as adjuvant medication in treating Covid 19. There is need of further clinical research to rule of exact action of Vasavaleha against Covid 19.


2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.


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.


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