The effects of 5 mg/L 1,2,4-trichlorobenzene （TCB） and 0.1 mmol/L mercury ion （Hg^2＋） stresses on Ca^2＋ fluxion and protein phosphorylation in rice seedlings were investigated by isotope exchange kinetics and in...The effects of 5 mg/L 1,2,4-trichlorobenzene （TCB） and 0.1 mmol/L mercury ion （Hg^2＋） stresses on Ca^2＋ fluxion and protein phosphorylation in rice seedlings were investigated by isotope exchange kinetics and in vitro phosphorylation assay. The Ca^2＋ absorption in rice leaves and Ca^2＋ transportation from roots to leaves were promoted significantly in response to Hg^2＋ and TCB treatments for 4-48 h. The Ca^2＋ absorption peaks presented in the leaves when the rice seedlings were exposed to Hg^2＋ for 8-12 h or to TCB for 12-24 h. Several Ca^2＋ absorption peaks presented in the roots during rice seedlings being exposed to Hg^2＋ and TCB, and the first Ca^2＋ absorption peak was at 8 h after being exposed to Hg^2＋ and TCB The result of isotope exchange kinetic analysis confirmed that short-term （8 h） Hg^2＋ and TCB stresses caused Ca^2＋ channels or pumps located on plasmalemma to open transiently. The phosphorylation assay showed that short-term TCB stress enhanced protein phosphorylation in rice roots （TCB treatment for 4-8 h） and leaves （TCB treatment for 4-24 h）, and short-term （4-8 h） Hg^2＋ stress also enhanced protein phosphorylation in rice leaves. The enhancement of protein phosphorylation in both roots and leaves corresponded with the first Ca^2＋ absorption peak, which confirmed that the enhancement of protein phosphorylation caused by TCB or Hg^2＋ stress might be partly triggered by the increases of cytosolic calcium. TCB treatment over 12 h inhibited protein phosphorylation in rice roots, which might be partly due to that TCB stress suppressed the protein kinase activity. Whereas, Hg^2＋ treatment inhibited protein phosphorylation in rice roots, and Hg^2＋ treatment over 12 h inhibited protein phosphorylation in rice leaves. This might be attributed to that not only the protein kinase activity, but also the expressions of phosphorylation proteins were restrained by Hg^2＋ stress.展开更多
Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichl...Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichlorobenzene(TCB)decomposition using NTP technology was investigated through a series of experiments,including voltage,frequency,water content,initial concentration,flow rate,and oxygen content.The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency.Oxygen has the greatest influence on TCB decomposition.The optimal reaction condition was at 15 kV,1000 Hz,an initial concentration of 20 mg m^?3,a flow rate of 2 l min^?1,H2O at 4%,and O2 at 0%.Under this condition,the TCB removal efficiency could reach 92%.According to the generated product backstepping,the hydroxyl radical(·OH)plays an important role in TCB decomposition due to its strong oxidation,which participates in the dechlorination and oxidation reactions as free radicals,and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts.It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.展开更多
Synthesis and kinetics of dichloro-methoxybenzenes were studied from 1,2,4-trichlorobenzene and sodium methoxide in a temperature range of 353--383 K. Effects of molar ratio of reactants, solvent and reaction temperat...Synthesis and kinetics of dichloro-methoxybenzenes were studied from 1,2,4-trichlorobenzene and sodium methoxide in a temperature range of 353--383 K. Effects of molar ratio of reactants, solvent and reaction temperature were investigated. Reaction products include three isomers. The order of selectivity for the three isomers was 1,4-dichloro-2-methoxybenzene〉〉2,4-dichoro-1-methoxybenzene〉,2-dichoro-4-methoxybenzene. Kinetic equations for the parallel liquid-solid interface reaction between 1,2,4-trichlorobenzene and sodium methoxide were established in the absence of catalyst. Kinetic parameters such as the pre-exponential factors and the activation energy were deter- mined with the Arrhenius equation.展开更多
The genetic information encoding metabolic pathways for xenobiotic compounds in bacteria often resides on catabolic plasmids.The aim of the present work was to know the location of the genes for degrading 1,2,4-trichl...The genetic information encoding metabolic pathways for xenobiotic compounds in bacteria often resides on catabolic plasmids.The aim of the present work was to know the location of the genes for degrading 1,2,4-trichlorobenzen.In this paper a 1,2,4-trichlorobenzene-degrading strain THSL-1 was isolated from the soil of Tianjin Chemical Plant using 1,2,4-trichlorobenzene as the sole carbon source.The strain was identified as Pseudomonas stutzeri through morphologic survey and 16S rDNA sequence determination.A plasmid was discovered from strain THSL-1 by using the alkali lysis method.When the plasmid was transformed into E.coli.JM109 by the CaCl2 method,the transformant could grow using 1,2,4-trichlorobenzene as the sole carbon source and had the degradation function of 1,2,4-trichlorobenzene.Therefore,it could be deemed that the plasmid carried the degradative genes of 1,2,4-trichlorobenzene.The average size of the plasmid was finally determined to be 40.2 Kb using selectively three kinds of restricted inscribed enzymes(HindIII,BamHI,and XholI)for single cutting and double cutting the plasmid pTHSL-1,respectively.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.30300026).
文摘The effects of 5 mg/L 1,2,4-trichlorobenzene （TCB） and 0.1 mmol/L mercury ion （Hg^2＋） stresses on Ca^2＋ fluxion and protein phosphorylation in rice seedlings were investigated by isotope exchange kinetics and in vitro phosphorylation assay. The Ca^2＋ absorption in rice leaves and Ca^2＋ transportation from roots to leaves were promoted significantly in response to Hg^2＋ and TCB treatments for 4-48 h. The Ca^2＋ absorption peaks presented in the leaves when the rice seedlings were exposed to Hg^2＋ for 8-12 h or to TCB for 12-24 h. Several Ca^2＋ absorption peaks presented in the roots during rice seedlings being exposed to Hg^2＋ and TCB, and the first Ca^2＋ absorption peak was at 8 h after being exposed to Hg^2＋ and TCB The result of isotope exchange kinetic analysis confirmed that short-term （8 h） Hg^2＋ and TCB stresses caused Ca^2＋ channels or pumps located on plasmalemma to open transiently. The phosphorylation assay showed that short-term TCB stress enhanced protein phosphorylation in rice roots （TCB treatment for 4-8 h） and leaves （TCB treatment for 4-24 h）, and short-term （4-8 h） Hg^2＋ stress also enhanced protein phosphorylation in rice leaves. The enhancement of protein phosphorylation in both roots and leaves corresponded with the first Ca^2＋ absorption peak, which confirmed that the enhancement of protein phosphorylation caused by TCB or Hg^2＋ stress might be partly triggered by the increases of cytosolic calcium. TCB treatment over 12 h inhibited protein phosphorylation in rice roots, which might be partly due to that TCB stress suppressed the protein kinase activity. Whereas, Hg^2＋ treatment inhibited protein phosphorylation in rice roots, and Hg^2＋ treatment over 12 h inhibited protein phosphorylation in rice leaves. This might be attributed to that not only the protein kinase activity, but also the expressions of phosphorylation proteins were restrained by Hg^2＋ stress.
基金the Major Science and Technology Projects of Shanxi Province(No.20181102017)the Hebei Province Central Guidance Local Science and Technology Development Special(No.19943816G)+1 种基金the Open Foundation of Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation(under planning)the Fundamental Research Funds for the Central Universities(No.2009QH03).
文摘Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichlorobenzene(TCB)decomposition using NTP technology was investigated through a series of experiments,including voltage,frequency,water content,initial concentration,flow rate,and oxygen content.The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency.Oxygen has the greatest influence on TCB decomposition.The optimal reaction condition was at 15 kV,1000 Hz,an initial concentration of 20 mg m^?3,a flow rate of 2 l min^?1,H2O at 4%,and O2 at 0%.Under this condition,the TCB removal efficiency could reach 92%.According to the generated product backstepping,the hydroxyl radical(·OH)plays an important role in TCB decomposition due to its strong oxidation,which participates in the dechlorination and oxidation reactions as free radicals,and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts.It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.
文摘Synthesis and kinetics of dichloro-methoxybenzenes were studied from 1,2,4-trichlorobenzene and sodium methoxide in a temperature range of 353--383 K. Effects of molar ratio of reactants, solvent and reaction temperature were investigated. Reaction products include three isomers. The order of selectivity for the three isomers was 1,4-dichloro-2-methoxybenzene〉〉2,4-dichoro-1-methoxybenzene〉,2-dichoro-4-methoxybenzene. Kinetic equations for the parallel liquid-solid interface reaction between 1,2,4-trichlorobenzene and sodium methoxide were established in the absence of catalyst. Kinetic parameters such as the pre-exponential factors and the activation energy were deter- mined with the Arrhenius equation.
基金This work was supported by the National High Technology Research and Development Program of China(863 Program)(Grant Nos.2002AA601170 and 2002A A601150).
文摘The genetic information encoding metabolic pathways for xenobiotic compounds in bacteria often resides on catabolic plasmids.The aim of the present work was to know the location of the genes for degrading 1,2,4-trichlorobenzen.In this paper a 1,2,4-trichlorobenzene-degrading strain THSL-1 was isolated from the soil of Tianjin Chemical Plant using 1,2,4-trichlorobenzene as the sole carbon source.The strain was identified as Pseudomonas stutzeri through morphologic survey and 16S rDNA sequence determination.A plasmid was discovered from strain THSL-1 by using the alkali lysis method.When the plasmid was transformed into E.coli.JM109 by the CaCl2 method,the transformant could grow using 1,2,4-trichlorobenzene as the sole carbon source and had the degradation function of 1,2,4-trichlorobenzene.Therefore,it could be deemed that the plasmid carried the degradative genes of 1,2,4-trichlorobenzene.The average size of the plasmid was finally determined to be 40.2 Kb using selectively three kinds of restricted inscribed enzymes(HindIII,BamHI,and XholI)for single cutting and double cutting the plasmid pTHSL-1,respectively.
