This work presents taboratory studies on the degradation of triazophos in intertidat sediment. The overall degradations were found to follow the first-order decay model. After being incubated for 6 d, the percentage o...This work presents taboratory studies on the degradation of triazophos in intertidat sediment. The overall degradations were found to follow the first-order decay model. After being incubated for 6 d, the percentage of degradations of triazophos in unsterilized and sterilized sediments were 94.5% and 20.5%, respectively. Between the temperatures of 15℃ and 35℃, the observed degradation rate constant（kob,d） enhanced as the incubation temperature increased. Triazophos in sediment degraded faster under aerobic condition than under anaerobic one. The water content of sediment had little influence on the degradation when it was in the range of 50%-100%. The values of kobsd decreased with increasing initial concentration of triazophos in sediment, which could result from the microorganism inhibition by triazophos. Four major degradation products, o, o-diethyl phosphorothioic acid, monoethyl phosphorothioic acid, phosphorothioic acid, and 1-phenyl-3-hydroxy-1, 2,4-triazole, were tentatively identified as their corresponding trimethylsilyl derivatives with a gas chromatography-mass spectrometer. The possible degradation pathway of triazophos in intertidal sediment was proposed. The results revealed that triazophos in intertidal sediment was relatively unstable and coutd be easily degraded.展开更多
Phytoremediation of triazophos （O,O-diethyl-O-（1-phenyl-1,2,4-triazole-3-base） sulfur phosphate, TAP） pollution by Canna indica Linn. in a hydroponic system has been well studied, whereas the microbial mechanism o...Phytoremediation of triazophos （O,O-diethyl-O-（1-phenyl-1,2,4-triazole-3-base） sulfur phosphate, TAP） pollution by Canna indica Linn. in a hydroponic system has been well studied, whereas the microbial mechanism on TAP degradation is still unknown. The variation in microbial community compositions was investigated by analyzing phospholipid fatty acids （PLFAs） profiles in microbes under TAP exposure. The TAP exposure resulted in an increase in proportions of fatty acid 16：0 and decrease in fatty acid 18：2ω9,12c, indicating that TAP may stimulate the reproduction of microorganisms and inhibit the growth of fungi to some degree. Significant correlation was found between the ratio of fungi to bacteria and TAP removal （r 2 = 0.840, p 0.01）. In addition, the microbial community in the phytoremediation system with C. indica was dominated by Gram negative bacteria, which possibly contributed to the degradation of TAP. These results indicated that TAP might induce the colonization of bacteria in the hydroponic system planted with C. indica, and lead to a discrimination of microbial community, which might be one of the mechanisms on TAP dissipation in phytoremediation system.展开更多
Effects of transgenic Bt rice on non-target pests following pesticide applications plays an important role in evaluating the ecological safety of transgenic rice. Changes of the life history parameters of laboratory p...Effects of transgenic Bt rice on non-target pests following pesticide applications plays an important role in evaluating the ecological safety of transgenic rice. Changes of the life history parameters of laboratory population of Nilaparvata lugens feeding on transgenic Bt rice T2A-1 and its parental line cv. MH63 as the control, and the contents of oxalic acid and soluble sugar following three pesticides （triazophos, jinggangmycin and chlorantraniliprole） treatments were investigated in this paper. Results showed that the population parameters of N. lugens and the physiological and biochemical parameters of rice did not differ significantly between T2A-1 and MH63 without pesticide application. But, the emergence rate （ER）, the nymphal number of next generation （NN）, and the index of population trend （IP） on T2A-1 treated with 10 mg L^-1 of triazophos were significantly higher than those on MH63, respectively, while the hatchability （HB） on T2A-1 treated with the three pesticides were obviously lower than those on MH 63. Furthermore, the content of oxalic acid in MH63 treated with 20 mg L-1 triazophos and, 40 and 80 mg L-1 chlorantraniliprole was significantly higher than that in T2A-1, while the content of soluble sugar in T2A-1 treated with 400 mg L-1 jinggangmycin was significantly higher than that in MH63. The results above indicated that triazophos in a low dose could cause a more favor of T2A-1 to population growth of N. lugens compared with MH 63.展开更多
The impact of triazophos, bensulfuron-methyl, chlobenthiazone on soil biochemical characteristics in a paddy soil under controlled moisture(flooded soil) and temperature(25℃) condition was studied. The electron trans...The impact of triazophos, bensulfuron-methyl, chlobenthiazone on soil biochemical characteristics in a paddy soil under controlled moisture(flooded soil) and temperature(25℃) condition was studied. The electron transport system(ETS)/dehydrogenase activity displayed a negative correlation with triazophos, bensulfuron-methyl, chlobenthiazone concentrations, and the activity decreased as the concentration of the pesticides increased. The higher doses, 5 and 10 field rates, of triazophos, bensulfuron-methyl, chlobenthiazone significantly inhibited ETS activity, while lower rates failed to produce any significant reducing effect against the control. The relative toxicity of triazophos, bensulfuron-methyl, chlobenthiazone in decreasing the ETS activity was in the order: triazophos > chlobenthiazone > bensulfuron-methyl, irrespective of the rates of application. Triazophos, bensulfuron-methyl, chlobenthiazone caused an improvement in the soil phenol content and it increased with increasing concentration of triazophos, bensulfuron-methyl, chlobenthiazone. Triazophos, bensulfuron-methyl, chlobenthiazone incorporation did not produce any significant change in soil protein content. The response of biomass phospholipid content was nearly similar to ETS activity. The phospholipid content was decreased with the addition of triazophos, bensulfuron-methyl, chlobenthiazone in the order of triazophos > chlobenthiazone > bensulfuron-methyl; and the toxicity of applied amount was in the order: 10 FR(field rate) > 5 FR > 1 0 FR > 0 5 FR > control.展开更多
To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT G...To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT GATGTG-3＇ and reverse primer 5＇-GYAAGTTRGCCCAATATCT-3＇. To express the gene, one sequence of the amplified DNA, which was able to encode a putative protein containing two conserved carboxylesterase domains, was connected to the prokaryotic expression vector PET-29a（＋）. The recombinant vector was transformed into Escherichia coil BL21（DE3）. Protein expression was induced by isopropy-D-thiogalactoside. The expressed ChE was used as an immunogen to immunize BALB/c mice. The obtained antibodies were tested for their specificity towards crude enzymes from species such as Alona milleri, Macrobrachium nipponense, Bombyx mori, Chironomus kiiensis, Apis mellifera, Eisenia foetida, Brachydanio rerio, and Xenopus laevis. Results indicated that the antibodies had specificity suitable for detecting ChE in Daphnia magna. A type of indirect and non-competitive enzyme-linked immunosorbent assay（IN-ELISA） was used to test the immunoreactive content of ChE（ChE-IR） in Daphina magna. The detection limit of the IN-ELISA was found to be 14.5 ng/ml at an antiserum dilution of 1：22 000. Results from tests on Daphnia magna exposed to sublethal concentrations of triazophos indicated a maximal induction of 57.2% in terms of ChE-IR on the second day after the animals were exposed to a concentration of 2.10 μg/L triazophos. Testing on animals acclimatized to a temperature of 16 °C indicated that ChE-IR was induced by 16.9% compared with the ChE-IR content detected at 21 °C, and the rate of induction was 25.6% at 10 °C. The IN-ELISA was also used to test the stability of ChE-IR in collected samples. Repeated freezing and thawing had no influence on the outcome of the test. All these results suggest that the polyclonal antibodies developed against the recombinant ChE are as efficient as those developed against the native ChE in detecting ChE content in Daphnia magna.展开更多
文摘This work presents taboratory studies on the degradation of triazophos in intertidat sediment. The overall degradations were found to follow the first-order decay model. After being incubated for 6 d, the percentage of degradations of triazophos in unsterilized and sterilized sediments were 94.5% and 20.5%, respectively. Between the temperatures of 15℃ and 35℃, the observed degradation rate constant（kob,d） enhanced as the incubation temperature increased. Triazophos in sediment degraded faster under aerobic condition than under anaerobic one. The water content of sediment had little influence on the degradation when it was in the range of 50%-100%. The values of kobsd decreased with increasing initial concentration of triazophos in sediment, which could result from the microorganism inhibition by triazophos. Four major degradation products, o, o-diethyl phosphorothioic acid, monoethyl phosphorothioic acid, phosphorothioic acid, and 1-phenyl-3-hydroxy-1, 2,4-triazole, were tentatively identified as their corresponding trimethylsilyl derivatives with a gas chromatography-mass spectrometer. The possible degradation pathway of triazophos in intertidal sediment was proposed. The results revealed that triazophos in intertidal sediment was relatively unstable and coutd be easily degraded.
基金supported by the National Natural Sci-ence Fundation of China (No. 20877093)the StateKey Laboratory of Freshwater Ecology and Biotechnology(No. 2008FBZ11)
文摘Phytoremediation of triazophos （O,O-diethyl-O-（1-phenyl-1,2,4-triazole-3-base） sulfur phosphate, TAP） pollution by Canna indica Linn. in a hydroponic system has been well studied, whereas the microbial mechanism on TAP degradation is still unknown. The variation in microbial community compositions was investigated by analyzing phospholipid fatty acids （PLFAs） profiles in microbes under TAP exposure. The TAP exposure resulted in an increase in proportions of fatty acid 16：0 and decrease in fatty acid 18：2ω9,12c, indicating that TAP may stimulate the reproduction of microorganisms and inhibit the growth of fungi to some degree. Significant correlation was found between the ratio of fungi to bacteria and TAP removal （r 2 = 0.840, p 0.01）. In addition, the microbial community in the phytoremediation system with C. indica was dominated by Gram negative bacteria, which possibly contributed to the degradation of TAP. These results indicated that TAP might induce the colonization of bacteria in the hydroponic system planted with C. indica, and lead to a discrimination of microbial community, which might be one of the mechanisms on TAP dissipation in phytoremediation system.
基金funded by the National Science and Technology Major Project of the Ministry of Science and Technology of China (2009ZX08011-009B)the Scientific Innovation Research of College Graduate in Jiangsu Province, China (CXZZ11-0986)
文摘Effects of transgenic Bt rice on non-target pests following pesticide applications plays an important role in evaluating the ecological safety of transgenic rice. Changes of the life history parameters of laboratory population of Nilaparvata lugens feeding on transgenic Bt rice T2A-1 and its parental line cv. MH63 as the control, and the contents of oxalic acid and soluble sugar following three pesticides （triazophos, jinggangmycin and chlorantraniliprole） treatments were investigated in this paper. Results showed that the population parameters of N. lugens and the physiological and biochemical parameters of rice did not differ significantly between T2A-1 and MH63 without pesticide application. But, the emergence rate （ER）, the nymphal number of next generation （NN）, and the index of population trend （IP） on T2A-1 treated with 10 mg L^-1 of triazophos were significantly higher than those on MH63, respectively, while the hatchability （HB） on T2A-1 treated with the three pesticides were obviously lower than those on MH 63. Furthermore, the content of oxalic acid in MH63 treated with 20 mg L-1 triazophos and, 40 and 80 mg L-1 chlorantraniliprole was significantly higher than that in T2A-1, while the content of soluble sugar in T2A-1 treated with 400 mg L-1 jinggangmycin was significantly higher than that in MH63. The results above indicated that triazophos in a low dose could cause a more favor of T2A-1 to population growth of N. lugens compared with MH 63.
文摘The impact of triazophos, bensulfuron-methyl, chlobenthiazone on soil biochemical characteristics in a paddy soil under controlled moisture(flooded soil) and temperature(25℃) condition was studied. The electron transport system(ETS)/dehydrogenase activity displayed a negative correlation with triazophos, bensulfuron-methyl, chlobenthiazone concentrations, and the activity decreased as the concentration of the pesticides increased. The higher doses, 5 and 10 field rates, of triazophos, bensulfuron-methyl, chlobenthiazone significantly inhibited ETS activity, while lower rates failed to produce any significant reducing effect against the control. The relative toxicity of triazophos, bensulfuron-methyl, chlobenthiazone in decreasing the ETS activity was in the order: triazophos > chlobenthiazone > bensulfuron-methyl, irrespective of the rates of application. Triazophos, bensulfuron-methyl, chlobenthiazone caused an improvement in the soil phenol content and it increased with increasing concentration of triazophos, bensulfuron-methyl, chlobenthiazone. Triazophos, bensulfuron-methyl, chlobenthiazone incorporation did not produce any significant change in soil protein content. The response of biomass phospholipid content was nearly similar to ETS activity. The phospholipid content was decreased with the addition of triazophos, bensulfuron-methyl, chlobenthiazone in the order of triazophos > chlobenthiazone > bensulfuron-methyl; and the toxicity of applied amount was in the order: 10 FR(field rate) > 5 FR > 1 0 FR > 0 5 FR > control.
基金supported by the Zhejiang Provincial Natural Science Foundation(No.LY12B07008),China
文摘To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT GATGTG-3＇ and reverse primer 5＇-GYAAGTTRGCCCAATATCT-3＇. To express the gene, one sequence of the amplified DNA, which was able to encode a putative protein containing two conserved carboxylesterase domains, was connected to the prokaryotic expression vector PET-29a（＋）. The recombinant vector was transformed into Escherichia coil BL21（DE3）. Protein expression was induced by isopropy-D-thiogalactoside. The expressed ChE was used as an immunogen to immunize BALB/c mice. The obtained antibodies were tested for their specificity towards crude enzymes from species such as Alona milleri, Macrobrachium nipponense, Bombyx mori, Chironomus kiiensis, Apis mellifera, Eisenia foetida, Brachydanio rerio, and Xenopus laevis. Results indicated that the antibodies had specificity suitable for detecting ChE in Daphnia magna. A type of indirect and non-competitive enzyme-linked immunosorbent assay（IN-ELISA） was used to test the immunoreactive content of ChE（ChE-IR） in Daphina magna. The detection limit of the IN-ELISA was found to be 14.5 ng/ml at an antiserum dilution of 1：22 000. Results from tests on Daphnia magna exposed to sublethal concentrations of triazophos indicated a maximal induction of 57.2% in terms of ChE-IR on the second day after the animals were exposed to a concentration of 2.10 μg/L triazophos. Testing on animals acclimatized to a temperature of 16 °C indicated that ChE-IR was induced by 16.9% compared with the ChE-IR content detected at 21 °C, and the rate of induction was 25.6% at 10 °C. The IN-ELISA was also used to test the stability of ChE-IR in collected samples. Repeated freezing and thawing had no influence on the outcome of the test. All these results suggest that the polyclonal antibodies developed against the recombinant ChE are as efficient as those developed against the native ChE in detecting ChE content in Daphnia magna.
