| Over the past decade, it has been recognized that environmental pollution is far greater than was previously assumed and that contaminants can remain in the environment for a long time, eventually accumulation to levels that could harm humans. Contamination of soils, sediments and water with toxic chemicals is one of the major problems facing the industrialized world today. Furthermore there is growing public concern that a wide variety of these toxic chemicals are being introduced into the environment. Heavy metals, which can be included in the main category of pollutants, can be found in soil, water and also in toxic gasses formed in the atmosphere by photochemical reactions. Chromium (Cr) and cadmium (Cd) are toxic metals that can result in severe damage to plants and animals. Copper (Cu) is known to an essential micronutrient for plants and animals, but it can be a toxic element, at a tissue concentration only slightly higher than optimal. Copper excess induces a wide range of biochemical effects and metaboli(?) disturbances on plants and animals. They were found in the environment as a result of anthropogenic activity such as stainless steel production, corrosion inhibition, wood preservation, the non-ferrous metal industry, mining, production, use and disposal, of batteries, metal-contaminated waste and sludge disposal, application of pesticides and phosphate fertilizers.Oxya chinensis (Thunberg) (Orthopera: Acrididae), which has not migratory feature, is one of the most common and widespread insects in Japan, Korea, Vietnam, United States (Hawaii), and Australia (North) . It is commonly and abundantly found in rice paddies, sugar cane and other crop fields, especially in China, where the outbreaks are increasing in both frequency and scale. It have long been known highly harmful pest to crops and forage plants. In recent years, O. chinensis continue to be a major economic pest of breaks crops in China. The oriental migratory locust, Locusta migratoria manilensis (Meyen) (Orthoptera: Oedipodidae) is a serious agricultural pest and distributed in Thailand, Burma, Singapore,Vietnam, Kampuchea, KoreaC South), Japan (South), and China. In terrestrial ecosystems grasshoppers occupy a significant position in the food chain. Staying in confined of the range of land, both O. chinemis and L. m, manilensis will suffer by one way or another if this ecosystem is contaminated by toxic substances and will take those toxic substances through orally food producing a series of effects on grasshoppers.The purposes of this research is to present toxic effects of heavy metals on O. chinensis and L. m. manilensis physiology and the toxic effects of Cd +, Cr6+ and deltamethrin on antioxidant enzymes of O. chinensis. This work was essential to improve our understanding of the distribution of Cd and Cu in O. chinensis and L. m. manilensis, and deltamethrin, heavy metals-oxidative stress relationship in O. chinensis. In the present study, l.an atomic absorption spectrophotometer was used to measure Cu and Cd concentrations in various parts of O. chinensis and L. m. manilensis, collected in Taiyuan and Linyi, Shanxi Province, respectively;2. we showed the relationships between distribution of heavy metals Cd and Cu in O. chinensis and gradual changes of exposed to Cd2+ in man-made soil-plant-insect system, which were determined with an atomic absorption spectrophotometer;3. In particular, the present work attempts to make a further study on the effect of Cd2+ in man-made soil-plant-insect system on changes in chemical composition, antioxidant enzyme activities, which were determined spectrophotometrically;4. it was assessed that the antioxidant enzymes had varied in grasshopper injected with Cd2+ and Cr(VI) and deltamethrin, which were determined spectrophotometrically;5. It was also reported that the survival of O. chinensis exposed to Cd2+ and Cr(VI) among allozyme genotypes, which was demonstrated with allozyme analysis.1. In this section, it was conducted to reveal distribution of heavy metal Cd in the insect. The results indicated that when environment had been polluted by Cd, the heavy metal was steadily accumulated in the body of O. chinensis. The result from our survey showed that the concentrations of Cd were different in each part of O. chinensis body. The distribution of Cd inboth female and male adult bodies of rice locust was 0.323 ^ 0.343 > 0.486 and 0.306 ug g"1, 0.323 ? 0.343 > 0.486 and 0.306 ug g"1, respectively. And the order of the concentrations for the pollutants was abdomen > thorax > head > hind femur and abdomen > head > thorax > hind femur of them, respectively. The concentrations of Cd were significant different between abdomen and head, abdomen and thorax, abdomen and hind femur. In addition, a significant difference for Cd was found in the abdomen between female and male. These results suggested that O. chinensis body had the capacity to hold Cd in different parts, and the capacity was different in different parts of O. chinensis. As the insect was very susceptible to Cd in soil, it may be suggested that the species be used as indicator organism pollution in soil. Therefore, it will correctly be known how the soil was polluted by Cd, providing some measures to reduce the pollution.2. When cadmium (Cd) and copper (Cu) appeared in environment, they were accumulated in the body of L. m. manilensis (Meyen). The result showed that the concentrations of Cd and Cu were different in each part of L. m. manilensis (Meyen). The distribution order of concentrations of Cd in adult bodies of L m. manilensis was testis> abdomen > alimentary canal > head > hind femur > thorax for male, and ovary > alimentary canal > abdomen > hind femur > head > thorax for female. The order of the Cu concentrations of L. m. manilensis was abdomen >testis> alimentary canal > head > hind femur > thorax for male, and abdomen > ovary > alimentary canal > head > thorax > hind femur for female. There were significant differences (p<0.001) of Cd and Cu concentration in different parts for male and female, and there were significant differences (p<0.05) in some parts and there were not any significant difference (p<0.05) in Cd and Cu contents in other parts else. Therefore, L. m. manilensis was body had the capacity to keep Cd and Cu in different parts, and the Cd and Cu concentrations were different in different parts of L. m. manilensis was.;3. Cadmium and Cu were studied for a man-made soil-plant-insect system comprising O. chinensis feeding on wheat {Triticum aestivum)seedlings. In the ecosystem, the Cd and Cu were found in plant. Although the concentrations of Cd in plant rose greatly with the increasing of Cd in the soil, the Cu content was not found elevated in Cd-treaded series. For famale grasshoppers, the result showed that (1). The Cu content in the head and thorax increased slightly as the level of Cd in both soil and plant increased;Cu content in the abdomen and hind femur decreased with the increasing of Cd level in soil and in plant. (2). Cd concentration of head, thorax and hind elevated firstly and then fell as the soil and plant level of Cd increased and they were all higher than that of the control;Cd in the abdomen increased with the Cd of soil and of plant increased and they were higher compared with the control;the Cd accumulation of femur increased at first six treatments and decreased at the last treatment as the increase of Cd level and all of them were higher compared to the control. There was a greatly significant difference (p<0.05) for four parts of Cu and Cd accumulation at all treatments. Though the order of Cu accumulation was abdomen>thorax > head > hind femur and the order of Cd accumulation was thorax > abdomen > head > hind femur, Cu and Cd content of each part varied as the Cd level in soil.For male grasshoppers, the result showed that (l).the accumulations of Cu in head, thorax changed slightly with the increasing content of Cd both in soil and in plant, but they were at the range of 4.37-5.68 mg kg"1 in head and 11.60-14.12 mg kg'1 in thorax. The accumulations of Cu in abdomen changed with the increasing content of Cd in both soil and plant, but they were lowei than that of the control. The accumulations of Cu in hind femur changed with the increasing content of Cd in soil and in plant, and the Cu accumulation decreased from treatment 5. (2). Cd concentration of head increased with the Cd level both in soil and in plant, but all of them were higher compared to the control;the accumulation of Cd in the thorax, abdomen and hind femur elevated firstly and then fell as the soil and plant level of Cd increased and they were all higher than that of the control. There was a greatly significant difference (p<0.05) for four parts of Cu and Cd accumulation at alltreatments. Though the order of Cu accumulation was abdomen >thorax > head > hind femur and the order of Cd accumulation was thorax > abdomen > head > hind femur, Cu and Cd content of each part varied as the Cd level in soil. The results indicated that Cd and Cu were accumulated from the soil to grasshoppers through the plant;that is to say, it is possible that Cd and Cu in environment were transported to animal or human through food chain. It is suggested that the O. chinensis could be a biomarker in soil-plant-soil system of the heavy metal contamination.4. One of purposes in this research was to determine the toxic effects of Cd2+on antioxidant enzymes of O. chinensis. Changes in the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were detedted in O. chinensis insects injected with Cd2+. Fifth-nymphs of O. chinensis insects were injected with Cd2+ at different concentrations (0, 55, 110, 165, 220, and 275 ug g"1). An increase of SOD activity in O. chinensis was observed at 110-275 ug g'1 Cd2+. The result of the effects of Cd2+ on antioxidant enzymes of O. chinensis showed that the SOD activity was lower at 220 and 275 ug g"1 than that at 110 and 165 ug g'1. It appears that SOD had a positive protective effect at low Cd2+ concentrations, and that this effect disappeared at high Cd concentrations. CAT activity was accelerated to varying degrees at 110-275 ug g"1 for males and at 110, 220, and 275 ug g"1 for females. CAT showed a strong detoxification effect with all treatments. GPx activity decreased with increasing Cd2+ concentration with all treatments for males and at 220 and 265 ug g"1 for females. We showed that GPx activity had a weak detoxification function with all treatments for males and at high Cd2+ for females, but CAT had a strong detoxification effect, whereas SOD had a. medium and GPx had a weak detoxification effect. Among the three enzymes, CAT played an important role in the damaging mechanisms of reactive oxygen species in O. chinensis insects.5. The toxic effects of Cr (VI) on antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), wasdetermined 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 ug g'1 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 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. Therci was not a consistent trend of GPx activities for males in all treatments of Cr (VI). Cr (Vl)-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.6. The purpose of this research is to present toxic effects of Cd on O. chinensis physiology. SOD, CAT, and GPx are important in the metabolism of reactive oxygen species (ROS), and can be induced by environmental stresses including cadmium, a heavy metal toxic to living organisms. O. chinensis was fed with wheat seedlings exposed to CdCl2 (0, 20, 40, 60, 80, 100, 120 mg kg'1 in soil) in man-made soil-plant-insect ecosystem for 30d and the activities of SOD, CAT, and GPx and content of H2O2 were analyzed. The result indicated that Cd2+ induced oxidative stress in O. chinensis insects increases with increasing Cd2+ concentration in the thorax and varied the enzymatic activities of antioxidative system (SOD, CAT, and GPx) and H2O2 content. (l)The activity of SOD was lower than that of the control for male, which indicated that SOD was inhibited by Cd2+;SOD was induced at highCd" concentration range for female. (2).With the increase of Cd' concentrations, CAT activities for both males and females decreased, which indicated that antioxidant system of O. chinensis was inhibited by the presence of Cd2+. (3). The GPx activity for both males and females increased at low Cd2+ concentration and decreased at high Cd2+ concentration, which revealed that the damage power of Cd2+ was increased with the increase of Cd2+ concentrations in terms of GPx. (4). The H2O2 content for both males and females increased with the increasing Cd2+ concentration, which suggested that the damage power of Cd2+ increased with the increasing Cd2+ concentrations in soil. There was a complex relationship between Cd2+ toxicity and defensive enzyme activity and multiple mechanisms rather than a single mechanism may be responsible for the capacity of O. chinensis insects to resist Cd2+.7. The primary object of this research was to examine the generality of asspciations of allozyme genotype with tolerance to cadmium (Cd) and chromium (Cr), we look for if the genotype of the enzymes glucose phosphate isomerase (GPI), phosphorglucomutase (PGM), malic enzyme (ME), and lactic dehydrogenase (LDH) factors affecting survival during acute Cd and Cr exposure. Allozyme horizontal starch gel electrophoresis has been used to analysis the genie structure of O. chinensis, collected from Yuanping, Shanxi and injected with 110.21 mg kg'1 of Cd (LD50) and 291.0 mgkg-'ofCr(LD5o).The results showed there were polymorphic loci at LDH, GPI, PGM and Me. The survival was not significant difference (P>0.05) for GPI loci, and was significant difference (P<0. 05) for PGM, LDH, and ME loci for O. chinensis treated with Cd. The X2 tests showed that the significant mortality differences were found among the following genotype pairs : LDH-AB vs. LDH-AA, LDH-AB vs. LDH-BB;PGM-CC vs. PGM-AA , PGM-CC vs. PGM-BB, PGM-CC vs. PGM-AB;Me-AA vs. Me-BB, Me-AA vs. Me-AC, Me-AA vs. Me-BC, Me-BB vs. Me-CC, Me-BB vs. Me-AB, Me-BB vs. Me-AC, Me-CC vs. Me-AC, Me-AB vs. Me-BC, Me-AC vs. Me-BC.Genotype frequencies deviated from the Hardy-Weinberg's expectations at PGM and Me, while fits Hardy-Weinberg's expectations at GPI. The excess of heterozygosis was for GPI (F<0), and the heterozygosis deficiency for LDH, PGM, ME(F>0). The data of the mean number of alleles per locus (A = 2.5), the observed mean heterozygosities (Ho=0.314-0.325) and the expected mean heterozygosities (He=0.471-0.496) of the species suggest that O. chinensis possesses sufficient genetic diversity.The survival was not significant difference (P>0.05) for GPI loci, and was significant difference (P<0. 05) for PGM, LDH, and ME loci for O. chinensis treated with Cr. The X2 tests showed that the significant mortality differences were found among the following genotype pairs : LDH-AA vs, LDH-BB, LDH-AB vs. LDH-BB;GPI-AA vs. GPI-BB, GPI-AB vs. GPI-BB;PGM-AB vs. PGM-BB, PGM-AB vs. PGM-BC;Me-AA vs. Me-BB, Me-AB vs. Me-BB, Me-AC vs. Me-BB, Me-BB vs. Me-BC, Me-BB vs. Me-CC. Genotype frequencies deviated from the Hardy-Weinberg's expectations at GPI, PGM and Me. The heterozygosis deficiency was at GPI, LDH, PGM, and ME (F>0) . The data of the mean number of alleles per locus (A = 2.5), the observed mean heterozygosities (Ho=0.276-0.324) and the expected mean heterozygosities (He=0.435-0.478) of the species suggest that O. chinensis possesses sufficient genetic diversity. In summary, it was different that lethal responses of allozyme genotypes of O. chinensis towards Cd and Cr.8. It has been documented that the pesticide deltamethrin, widely used for it low toxicity and high efficiency, causes alterations in various enzymatic systems in insects. This study examined the activities of superoxide dismutase (SOD) and glutathione peroxidasse (GPx) in O. chinensis injected with deltamethrin concentration series. The SOD activity increased in the grasshoppers exposed to deltamethrin of low concentrations. However the high concentrations of the pesticide were found inhibitive to SOD activity. Meanwhile the significant different was not found in all treatments of deltamethrin, and O. chinensis showed significant sexual difference in SOD activities then exposed to deltamethrin of 0.02 ,0.14 and 0.26 ug uL~'. Theactivities of GPx were not significant different in all treatments of deltamethrin. And similar sexual variation was also observed in GPx at concentrations of 0.02 to 0.14 ug uL"1, whose activities is enhanced by deltamethrin at lower concentrations but inhibited at high concentrations in male grasshoppers. In contrast, the female grasshoppers showed opposite response. The data suggested that O.chinensis may respond through biochemical and physiological regulations to deltamethrin of lower concentrations, beyond which the toxic effects could be non-nonreversible.
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