The susceptibility of Oxya chinensis to malathion was compared in larvae and adults from a field population, collected from Jinyuan outskirt, Shanxi Province. The results showed that Oxya chinensis was more suscepti...The susceptibility of Oxya chinensis to malathion was compared in larvae and adults from a field population, collected from Jinyuan outskirt, Shanxi Province. The results showed that Oxya chinensis was more susceptible to malathion in the adult stage than in the larval stage. The LD50 values for malathion susceptibility of Oxya chinensis were 4.94 and 2.44 mg g-1 body weight in the larvae and adults respectively. The results indicated that the larvae were 2.02-fold less susceptible to malathion than the adults. The general esterases and the kinetics were characterized and compared between the two life stages and between females and males. Larval preparations of Oxya chinensis were more active than adult preparations in females and males. The larvae showed 1.18-, 1.49-, and 1.17- fold higher specific activities than the adults in females with α-NA, α-NB and β-NA respectively. In males, the ratios were 1.34-, 1.70-, and 1.06-fold. Female preparations were more active than those of males in the adults. The reverse results were observed in the larvae where male preparations were more active than female preparations. Kinetic studies showed that Km values of general esterases hydrolyzing α-NA, α-NB, and β-NA in the adult stage were 1.36-, 1.32- and 1.39-fold respectively, higher than those in the larval stage in females. In males, the ratios were 1.24-, 2.14-, and 1.20-fold. The esterase from male insects had a higher affinity (lower Km value) to the substrate than those from females. The results also showed that the Vmax values of general esterase hydrolyzing α-NA, α-NB, and β-NA in the two stages were similar. From the results of bioassays and biochemical analyses, it has been inferred that a higher level of resistance to malathion in larvae than in adults would appear to result from differences in the expression of resistance mechanisms in these two life stages. Enhanced esterase activities appeared to play a major role in resistance to malathion in both larvae and adults. From the analysis of inhibition in vitro, the esterases in the two life stages were B-type, and carboxylesterases were predominant enzymes in the composition of the esterases in the two stages.展开更多
In this study, acetylcholinesterase (AChE) was extracted from two field-collected populations of Oxya chinensis (XinxiangCity, Henan Province and Changzhi City, Shanxi Province). AChE activities were decreased when co...In this study, acetylcholinesterase (AChE) was extracted from two field-collected populations of Oxya chinensis (XinxiangCity, Henan Province and Changzhi City, Shanxi Province). AChE activities were decreased when concentrations of ATCincreased, showing a characteristic phenomenon of substrate inhibition at high concentration in both populations. Suchinhibition occurred at relatively low concentration for AChE from Xinxiang population but relatively high for AChE fromChangzhi population. The kinetic study showed that there were no significant differences between the two populations inthe Km values. The Km value in Changzhi population was only 1.09-fold higher than that in Xinxiang population. However,significant differences were observed between the two populations in Vmax values. The Vmax value in Changzhi populationwas 1.32-fold higher than that in Xinxiang population. The inhibition study in vitro showed that the AChE from bothpopulations exhibited similar rank order in sensitivity to inhibition by three OPs, as determined by comparison of theirbimolecular rate constants (ki), from the most potent inhibition to the least was chlopyrifos-oxon > paraoxon >demeton-s-methyl for AChE from the two populations and that the ki values in Xinxiang population were lower than those in Changzhipopulation. The I50 values of AChE from Xinxiang population were 4.84-, 2.66-, and 1.92-fold less sensitive to inhibition byparaoxon, chlopyrifos-oxon, and demeton-s-methyl. These results were consistent with the results in bioassay. It isinferred that AChE insensitivity to OP insecticides plays an important role in the differences of insusceptibility of Oxyachinensis to malathion between the two populations.展开更多
Specific activity, substrate specificity, and kinetic parameters （Km and Vmax） of glutathione S-transferases （GSTs） towards three substrates, 1-chloro-2,4-dinitrobenzene （CDNB）, 1,2-dichloro-4-nitrobenzene （DCN...Specific activity, substrate specificity, and kinetic parameters （Km and Vmax） of glutathione S-transferases （GSTs） towards three substrates, 1-chloro-2,4-dinitrobenzene （CDNB）, 1,2-dichloro-4-nitrobenzene （DCNB）, and p-nitrobenzene chloride （pNBC） were investigated in six tissues （foregut, midgut, hindgut, fat body, hemolymph, and muscle） of Oxya chinensis. In addition, the inhibition in vitro （ethacrynic acid, and Cibacron Blue 3GA） of Oxya chinensis in the six tissues was also investigated. Glutathione S-transferase activity was detected in all the six tissues examined. The rank order of GST activities towards CDNB was fat body 〉 midgut 〉 hindgut 〉 muscle 〉 foregut 〉 hemolymph both in females and males. Glutathione S-transferase activities in the fat body in females and males were 1.3- to 10.4-fold and 1.1- to 10.0- fold higher than those in the other tissues. The rank order of GST activities towards the other substrates changed slightly. From these results, it was inferred that GSTs in the fat body and midgut played important roles in detoxifying xenobiotics including insecticides and plant allelochemicals in O. chinensis. In the three substrates examined, CDNB seemed to be the best substrate, followed by pNBC and DCNB. The kinetic parameters of GSTs were different among the six tissues. This suggested that GSTs in different tissues have various affinities and catalytic efficiency to substrates. In vitro inhibition study showed that the median inhibition concentration （IC50） values of the two inhibitors to GSTs from the six tissues were different. The results suggested that the two inhibitors have different inhibition potency to GSTs from the different tissues. The observed changes in kinetic parameters and inhibition in vitro among the six tissues of the insect might suggest that the number and structure of isoenzymes and their rate of expression varied for the different tissues.展开更多
The toxic effects of Cr（Vl） on antioxidant enzymes of Oxya chinensis（Orthoptera： Acridoidae） were determined. Changes in the activities of the antioxidant enzymes superoxide dismutase（SOD）, catalase（CAT）, and...The toxic effects of Cr（Vl） on antioxidant enzymes of Oxya chinensis（Orthoptera： Acridoidae） were determined. Changes in the activities of the antioxidant enzymes superoxide dismutase（SOD）, catalase（CAT）, and guaiacol peroxidase（GPx） were measured in O. chinensis insects injected with Cr（VI）. Fifth-nymphs of O. chinensis insects were injected with Cr（VI） with different concentrations （0, 75, 150, 225, 300, 375, 450 mg/kg of body weight）. The results showed that Cr（VI） led to the change of SOD, CAT, and GPx activities at different concentrations, which revealed that： （1） The oxidative stress of SOD increased with the increase of Cr （VI） concentration. （2） With the increase of Cr （VI） concentrations, CAT activities for females increased at lower concentrations, but decreased at higher concentration range, which indicated that antioxidant system of O. chinensis was not influenced by the presence of Cr （VI）. A very similar response to Cr（VI） effect for males indicated that Cr（VI） concentrations were not high enough to damage O. chinensis in terms of CAT. （3） The GPx activity for females increased in all treatments, which revealed that the damage power of Cr（VI） was increased with the increase of Cr（Vi） concentrations in terms of GPx, but the effect was not so remarkable. There was not a consistent trend of GPx activities for males in all treatments of Cr（VI）. Cr（VI）-induced changes in antioxidant enzymes were different for SOD, CAT and GPx, of which the tendency was that activities generally changed with increase of concentrations of Cr（VI） suggesting SOD, CAT, and GPx could serve as indices of oxidative stress to some extent.展开更多
The susceptibilities of Oxya chinensis to malathion were studied in three populations collected from outskirt of Tianjin, China, using bioassays and biochemical analysis. Populations were chosen to represent different...The susceptibilities of Oxya chinensis to malathion were studied in three populations collected from outskirt of Tianjin, China, using bioassays and biochemical analysis. Populations were chosen to represent different exposure to insecticides： BDG （Beidagang; low exposure）, BD （Baodi; high exposure previously but low exposure now）, and JN （Jinnan; high exposure）. The results showed that the LD50 values of BD and JN populations were 3.95- and 12.02-fold and 3.64- and 10.07- fold higher than that of BDG population in females and males, respectively. The LD50 values in females were higher than those in males. The results of biochemical analysis indicated that the esterase （EST） activities in JN population were higher than those in BD and BDG populations. They showed that when α-NA, α-NB, and α-NA were used as substrates, females＇ EST activities of JN population were 1.11-, 1.30-, and 1.14-fold and 1.39-, 1.59-, and 1.54-fold higher than those of BD and BDG populations, respectively. When α-NA, α-NB, and β-NA were used as substrates, males＇ EST activities of JN population were 1.13-, 1.12-, and 1,00-fold and 1.20-, 1.14-, and 1.07-fold higher than those of BD and BDG populations, respectively. The results also showed that the specific activities of the females were higher than those of the males in the BD and JN populations, whereas the specific activities of the males were higher than those of the females in the BDG population. The results of bioassay were consistent with those of biochemical analysis. Thus, it was inferred that the elevated ESTs activities might play an important role in conferring the differences of susceptibility of O. chinensis to malathion in the three collected populations. Enzyme kinetic studies indicated that the Km and Vmax values were different among the three collected populations and between the females and the males. The observed changes in the kinetic parameters might be explained by differential expression patterns of isozymes so that the insect esterases have different affinities and maximum velocities toward the same substrate.展开更多
Genetic relationship among Oxya chinensis populations and Oxya japonica populations collected from Xuzhou City, Jiangsu Province and Pingshan County, Hebei Province, China were analyzed by random amplified polymorphic...Genetic relationship among Oxya chinensis populations and Oxya japonica populations collected from Xuzhou City, Jiangsu Province and Pingshan County, Hebei Province, China were analyzed by random amplified polymorphic DNA （RAPD） markers. A total of 125 DNA bands ranging from 200 to 2 200 bp were amplified by 10 random primers in DNA samples from 43 grasshopper individuals. One hundred and twenty-three （99%） of these bands were polymorphic. Shannon＇s index showed that the genetic, diversity within O. chinensis （0.3432） was higher than that of O. japonica （0.2781）. Nei＇s genetic distance between O. chinensis population and O. japonica population from the same area was less than that between populations from two different areas. The dendrogram based on Nei＇s genetic distance of RAPD markers was constructed using the unweighted pair group method with the arithmetic average （UPGMA） and Neighbor-Joining （NJ） methods. Cluster analysis indicated that all the individuals were grouped into two main clusters. O. chinensis populations from Xuzhou and Pingshan formed one cluster, and O. japonica populations from the two regions belonged to another cluster. The results demonstrated that RAPD can detect within species, and among closely related species. polymorphisms to distinguish minor difference among individuals展开更多
Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1...Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1,250 mM; A2, 450 mM; A3,750 mM; A4, 1 000 mM）. Mortality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs）, and glutathione peroxidase （GPx） were determinated. The mortality of O. chinensis rose with an increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19 and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in the A4 treatment declined by 51.53 and 42.82% in the female, and 42.65 and 43.85% in the male compared to the control, respectively, and the degree of decline reached a significant level at P 〈 0.05. Meanwhile, the GSTs activities of O. chinensis enhanced with increasing dose of ALA. The GSTs activities of female and male O. chinensis in the A4 treatment remarkably increased by 171.05 and 97.42% compared to the control （P〈 0.05）. ALA had an obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capability to defend oxidation damage declining. Meanwhile, a high dose of ALA could activate GSTs, which caused a feedback inhibition of the insect to the phototoxic substance.展开更多
5-Aminolevulinic acid （ALA）, a major photosensitivity insecticide, has attracted increasing attention as a new type of highly efficient, environmental friendly pesticide to be used to control the pest. To examine wh...5-Aminolevulinic acid （ALA）, a major photosensitivity insecticide, has attracted increasing attention as a new type of highly efficient, environmental friendly pesticide to be used to control the pest. To examine whether or not ALA acts effectively to grasshopper, Oxya chinensis and elucidate the detoxification mechanism of ALA, the susceptibility to ALA was assessed in O. chinensis and two major metabolic detoxification enzymes including glutathione S-transferases （GSTs） and general esterases （ESTs）-specific activities were compared in different development stages and different body sections of O. chinensis treated by ALA and the control. The results showed that the ALA exhibited obvious toxicity to the grasshopper in different development stages. In the low-dose treatment （0.0597 mmol L-1）, the mortalities of O. chinensis reached a significant level （55.5% in the 1st instar nymphs, 61.4% in the 2nd instar nymphs, 71.4% in the 3rd instar nymphs, and 64.4% in the 4th instar nymphs. But, there was no dose-dependent toxic effect. Thereby, we proposed that ALA has the potential for acting as photosensitivity insecticide for controlling O. chinensis. GSTs activity assays using CDNB and DCNB as substrates indicated that the thorax and abdomen of the different instar nymphs treated by ALA showed 1.52-5.56 fold significantly increased GSTs activities compared with the control. However, for the ESTs-specific activity assay, there was no significant difference between O. chinensis treated by ALA and the control within different instar nymphs, when a-NA, a-NB and b-NA were used as substrates. Therefore, GSTs-mediated metabolic detoxification as evidenced by significantly increased GSTs activities might contribute to protect against oxidative damage and oxidative stress by ALA in O. chinensis.展开更多
The goal of the present study was to compare the different survival of Oxya chinensis exposed to chromium（VI） among allozyme genotypes to gain a better understanding of the relationship between the genetic variation...The goal of the present study was to compare the different survival of Oxya chinensis exposed to chromium（VI） among allozyme genotypes to gain a better understanding of the relationship between the genetic variations and environmental disturbance. This study analyzed the occurrence of genotypes in O. chinensis population exposed to Cr（VI）. O. chinensis samples were collected at Yuanping, Shanxi Province, China and used in acute toxicity tests. Specimens were assigned to Cr（VI） exposure （LDs0：291.0 mg/kg） for 24 h. The genetic composition of both dead and survived specimens was analyzed with horizontal starch gel electrophoresis in four enzymes （GPI, PGM, LDH, and ME）. The results indicated that under Cr（VI） exposure, specimens with different genotypes had various mortalities at the four loci in laboratory conditions, and there was a genetic basis for tolerance in O. chinensis during acute exposure to Cr（VI）.展开更多
基金supported by the National Natura1 Science Foundation of China(30170612)the Science and Technology Commission of Shanxi Province(041005)to MA Enbo.
文摘The susceptibility of Oxya chinensis to malathion was compared in larvae and adults from a field population, collected from Jinyuan outskirt, Shanxi Province. The results showed that Oxya chinensis was more susceptible to malathion in the adult stage than in the larval stage. The LD50 values for malathion susceptibility of Oxya chinensis were 4.94 and 2.44 mg g-1 body weight in the larvae and adults respectively. The results indicated that the larvae were 2.02-fold less susceptible to malathion than the adults. The general esterases and the kinetics were characterized and compared between the two life stages and between females and males. Larval preparations of Oxya chinensis were more active than adult preparations in females and males. The larvae showed 1.18-, 1.49-, and 1.17- fold higher specific activities than the adults in females with α-NA, α-NB and β-NA respectively. In males, the ratios were 1.34-, 1.70-, and 1.06-fold. Female preparations were more active than those of males in the adults. The reverse results were observed in the larvae where male preparations were more active than female preparations. Kinetic studies showed that Km values of general esterases hydrolyzing α-NA, α-NB, and β-NA in the adult stage were 1.36-, 1.32- and 1.39-fold respectively, higher than those in the larval stage in females. In males, the ratios were 1.24-, 2.14-, and 1.20-fold. The esterase from male insects had a higher affinity (lower Km value) to the substrate than those from females. The results also showed that the Vmax values of general esterase hydrolyzing α-NA, α-NB, and β-NA in the two stages were similar. From the results of bioassays and biochemical analyses, it has been inferred that a higher level of resistance to malathion in larvae than in adults would appear to result from differences in the expression of resistance mechanisms in these two life stages. Enhanced esterase activities appeared to play a major role in resistance to malathion in both larvae and adults. From the analysis of inhibition in vitro, the esterases in the two life stages were B-type, and carboxylesterases were predominant enzymes in the composition of the esterases in the two stages.
基金supported by National Natural Science Foundation of China(30170612)Science and Technology Commission of Shanxi Province(041005)to Ma Enbo
文摘In this study, acetylcholinesterase (AChE) was extracted from two field-collected populations of Oxya chinensis (XinxiangCity, Henan Province and Changzhi City, Shanxi Province). AChE activities were decreased when concentrations of ATCincreased, showing a characteristic phenomenon of substrate inhibition at high concentration in both populations. Suchinhibition occurred at relatively low concentration for AChE from Xinxiang population but relatively high for AChE fromChangzhi population. The kinetic study showed that there were no significant differences between the two populations inthe Km values. The Km value in Changzhi population was only 1.09-fold higher than that in Xinxiang population. However,significant differences were observed between the two populations in Vmax values. The Vmax value in Changzhi populationwas 1.32-fold higher than that in Xinxiang population. The inhibition study in vitro showed that the AChE from bothpopulations exhibited similar rank order in sensitivity to inhibition by three OPs, as determined by comparison of theirbimolecular rate constants (ki), from the most potent inhibition to the least was chlopyrifos-oxon > paraoxon >demeton-s-methyl for AChE from the two populations and that the ki values in Xinxiang population were lower than those in Changzhipopulation. The I50 values of AChE from Xinxiang population were 4.84-, 2.66-, and 1.92-fold less sensitive to inhibition byparaoxon, chlopyrifos-oxon, and demeton-s-methyl. These results were consistent with the results in bioassay. It isinferred that AChE insensitivity to OP insecticides plays an important role in the differences of insusceptibility of Oxyachinensis to malathion between the two populations.
基金supported by the National Natural Science Foundation of China(30570247,30470219)Science and Technology Commission of Shanxi Province,China(041005,2006011075).
文摘Specific activity, substrate specificity, and kinetic parameters （Km and Vmax） of glutathione S-transferases （GSTs） towards three substrates, 1-chloro-2,4-dinitrobenzene （CDNB）, 1,2-dichloro-4-nitrobenzene （DCNB）, and p-nitrobenzene chloride （pNBC） were investigated in six tissues （foregut, midgut, hindgut, fat body, hemolymph, and muscle） of Oxya chinensis. In addition, the inhibition in vitro （ethacrynic acid, and Cibacron Blue 3GA） of Oxya chinensis in the six tissues was also investigated. Glutathione S-transferase activity was detected in all the six tissues examined. The rank order of GST activities towards CDNB was fat body 〉 midgut 〉 hindgut 〉 muscle 〉 foregut 〉 hemolymph both in females and males. Glutathione S-transferase activities in the fat body in females and males were 1.3- to 10.4-fold and 1.1- to 10.0- fold higher than those in the other tissues. The rank order of GST activities towards the other substrates changed slightly. From these results, it was inferred that GSTs in the fat body and midgut played important roles in detoxifying xenobiotics including insecticides and plant allelochemicals in O. chinensis. In the three substrates examined, CDNB seemed to be the best substrate, followed by pNBC and DCNB. The kinetic parameters of GSTs were different among the six tissues. This suggested that GSTs in different tissues have various affinities and catalytic efficiency to substrates. In vitro inhibition study showed that the median inhibition concentration （IC50） values of the two inhibitors to GSTs from the six tissues were different. The results suggested that the two inhibitors have different inhibition potency to GSTs from the different tissues. The observed changes in kinetic parameters and inhibition in vitro among the six tissues of the insect might suggest that the number and structure of isoenzymes and their rate of expression varied for the different tissues.
基金The National Natural Science Foundation of China(No.30170612 30470219) International Cooperation of Shanxi Province(No.041005)
文摘The toxic effects of Cr（Vl） on antioxidant enzymes of Oxya chinensis（Orthoptera： Acridoidae） were determined. Changes in the activities of the antioxidant enzymes superoxide dismutase（SOD）, catalase（CAT）, and guaiacol peroxidase（GPx） were measured in O. chinensis insects injected with Cr（VI）. Fifth-nymphs of O. chinensis insects were injected with Cr（VI） with different concentrations （0, 75, 150, 225, 300, 375, 450 mg/kg of body weight）. The results showed that Cr（VI） led to the change of SOD, CAT, and GPx activities at different concentrations, which revealed that： （1） The oxidative stress of SOD increased with the increase of Cr （VI） concentration. （2） With the increase of Cr （VI） concentrations, CAT activities for females increased at lower concentrations, but decreased at higher concentration range, which indicated that antioxidant system of O. chinensis was not influenced by the presence of Cr （VI）. A very similar response to Cr（VI） effect for males indicated that Cr（VI） concentrations were not high enough to damage O. chinensis in terms of CAT. （3） The GPx activity for females increased in all treatments, which revealed that the damage power of Cr（VI） was increased with the increase of Cr（Vi） concentrations in terms of GPx, but the effect was not so remarkable. There was not a consistent trend of GPx activities for males in all treatments of Cr（VI）. Cr（VI）-induced changes in antioxidant enzymes were different for SOD, CAT and GPx, of which the tendency was that activities generally changed with increase of concentrations of Cr（VI） suggesting SOD, CAT, and GPx could serve as indices of oxidative stress to some extent.
基金supported by the National Natural Science Foundation of China (30570247)the Science and Technology Commission of Shanxi Province,China (2006011075)
文摘The susceptibilities of Oxya chinensis to malathion were studied in three populations collected from outskirt of Tianjin, China, using bioassays and biochemical analysis. Populations were chosen to represent different exposure to insecticides： BDG （Beidagang; low exposure）, BD （Baodi; high exposure previously but low exposure now）, and JN （Jinnan; high exposure）. The results showed that the LD50 values of BD and JN populations were 3.95- and 12.02-fold and 3.64- and 10.07- fold higher than that of BDG population in females and males, respectively. The LD50 values in females were higher than those in males. The results of biochemical analysis indicated that the esterase （EST） activities in JN population were higher than those in BD and BDG populations. They showed that when α-NA, α-NB, and α-NA were used as substrates, females＇ EST activities of JN population were 1.11-, 1.30-, and 1.14-fold and 1.39-, 1.59-, and 1.54-fold higher than those of BD and BDG populations, respectively. When α-NA, α-NB, and β-NA were used as substrates, males＇ EST activities of JN population were 1.13-, 1.12-, and 1,00-fold and 1.20-, 1.14-, and 1.07-fold higher than those of BD and BDG populations, respectively. The results also showed that the specific activities of the females were higher than those of the males in the BD and JN populations, whereas the specific activities of the males were higher than those of the females in the BDG population. The results of bioassay were consistent with those of biochemical analysis. Thus, it was inferred that the elevated ESTs activities might play an important role in conferring the differences of susceptibility of O. chinensis to malathion in the three collected populations. Enzyme kinetic studies indicated that the Km and Vmax values were different among the three collected populations and between the females and the males. The observed changes in the kinetic parameters might be explained by differential expression patterns of isozymes so that the insect esterases have different affinities and maximum velocities toward the same substrate.
基金This work was supported by the National Natural Science Foundation of China （30470219, 30570247）Natural Science Foundation of Shanxi Province, China （991096）.
文摘Genetic relationship among Oxya chinensis populations and Oxya japonica populations collected from Xuzhou City, Jiangsu Province and Pingshan County, Hebei Province, China were analyzed by random amplified polymorphic DNA （RAPD） markers. A total of 125 DNA bands ranging from 200 to 2 200 bp were amplified by 10 random primers in DNA samples from 43 grasshopper individuals. One hundred and twenty-three （99%） of these bands were polymorphic. Shannon＇s index showed that the genetic, diversity within O. chinensis （0.3432） was higher than that of O. japonica （0.2781）. Nei＇s genetic distance between O. chinensis population and O. japonica population from the same area was less than that between populations from two different areas. The dendrogram based on Nei＇s genetic distance of RAPD markers was constructed using the unweighted pair group method with the arithmetic average （UPGMA） and Neighbor-Joining （NJ） methods. Cluster analysis indicated that all the individuals were grouped into two main clusters. O. chinensis populations from Xuzhou and Pingshan formed one cluster, and O. japonica populations from the two regions belonged to another cluster. The results demonstrated that RAPD can detect within species, and among closely related species. polymorphisms to distinguish minor difference among individuals
基金the National Natural Science Foundation of China(30570247)Study Abroad Foundation of Shanxi Province,Natural Science Foundation of Shanxi Province(2006011075)Youth Foundation of Shanxi Province,China(2007021030).
文摘Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1,250 mM; A2, 450 mM; A3,750 mM; A4, 1 000 mM）. Mortality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs）, and glutathione peroxidase （GPx） were determinated. The mortality of O. chinensis rose with an increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19 and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in the A4 treatment declined by 51.53 and 42.82% in the female, and 42.65 and 43.85% in the male compared to the control, respectively, and the degree of decline reached a significant level at P 〈 0.05. Meanwhile, the GSTs activities of O. chinensis enhanced with increasing dose of ALA. The GSTs activities of female and male O. chinensis in the A4 treatment remarkably increased by 171.05 and 97.42% compared to the control （P〈 0.05）. ALA had an obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capability to defend oxidation damage declining. Meanwhile, a high dose of ALA could activate GSTs, which caused a feedback inhibition of the insect to the phototoxic substance.
基金supported by the National Natural Science Foundation of China (30870302 and 30970410)the Youth Foundation of Shanxi Province, China (2007021030)the Research Fund for the Doctoral Program of Higher Education of China (20101401120008)
文摘5-Aminolevulinic acid （ALA）, a major photosensitivity insecticide, has attracted increasing attention as a new type of highly efficient, environmental friendly pesticide to be used to control the pest. To examine whether or not ALA acts effectively to grasshopper, Oxya chinensis and elucidate the detoxification mechanism of ALA, the susceptibility to ALA was assessed in O. chinensis and two major metabolic detoxification enzymes including glutathione S-transferases （GSTs） and general esterases （ESTs）-specific activities were compared in different development stages and different body sections of O. chinensis treated by ALA and the control. The results showed that the ALA exhibited obvious toxicity to the grasshopper in different development stages. In the low-dose treatment （0.0597 mmol L-1）, the mortalities of O. chinensis reached a significant level （55.5% in the 1st instar nymphs, 61.4% in the 2nd instar nymphs, 71.4% in the 3rd instar nymphs, and 64.4% in the 4th instar nymphs. But, there was no dose-dependent toxic effect. Thereby, we proposed that ALA has the potential for acting as photosensitivity insecticide for controlling O. chinensis. GSTs activity assays using CDNB and DCNB as substrates indicated that the thorax and abdomen of the different instar nymphs treated by ALA showed 1.52-5.56 fold significantly increased GSTs activities compared with the control. However, for the ESTs-specific activity assay, there was no significant difference between O. chinensis treated by ALA and the control within different instar nymphs, when a-NA, a-NB and b-NA were used as substrates. Therefore, GSTs-mediated metabolic detoxification as evidenced by significantly increased GSTs activities might contribute to protect against oxidative damage and oxidative stress by ALA in O. chinensis.
基金supported by the National Natural Science Foundation of China (No. 30570247)the Doctoral Foundation of Shanxi Academy of Agriculture Sciences (No. YBJJ0702)
文摘The goal of the present study was to compare the different survival of Oxya chinensis exposed to chromium（VI） among allozyme genotypes to gain a better understanding of the relationship between the genetic variations and environmental disturbance. This study analyzed the occurrence of genotypes in O. chinensis population exposed to Cr（VI）. O. chinensis samples were collected at Yuanping, Shanxi Province, China and used in acute toxicity tests. Specimens were assigned to Cr（VI） exposure （LDs0：291.0 mg/kg） for 24 h. The genetic composition of both dead and survived specimens was analyzed with horizontal starch gel electrophoresis in four enzymes （GPI, PGM, LDH, and ME）. The results indicated that under Cr（VI） exposure, specimens with different genotypes had various mortalities at the four loci in laboratory conditions, and there was a genetic basis for tolerance in O. chinensis during acute exposure to Cr（VI）.
