cDNA libraries were constructed from the leaves of a rice (Oryza sativa L.) salt tolerancevariety Tesan抋i 2 growing in solutions with 150 mmol/L NaCl for 3 h or without salt stress. Three salt-responsive cDNA clones,...cDNA libraries were constructed from the leaves of a rice (Oryza sativa L.) salt tolerancevariety Tesan抋i 2 growing in solutions with 150 mmol/L NaCl for 3 h or without salt stress. Three salt-responsive cDNA clones, Ts1, Ts2 and Ts3 were isolated by differential screening. Northern blottinganalysis showed that the transcription levels of Ts1 and Ts2 increased within 3 h salt stress and kept onincreasing within 24 h, while the transcription level of Ts3 reached its peak within 3 h. Sequence analysisindicated that there were no homologies between the three cDNA clones and any known gene. The threecDNA clones were mapped using a doubled haploid (DH) population derived from an indica variety ZYQ8,which was a salt tolerance parent of Tesan抋i 2, with a japonica variety JX17. Ts1, Ts2 and Ts3 werelocated on chromosomes 1, 3 and 7, respectively. It was noted that Ts1, Ts2, and Ts3 were in or near theregions of major or minor salt tolerance quantitative trait loci (QTLs), which were mapped in the same DHpopulation in a parallel study.展开更多
The corrosion behavior of C100 steel in simulated environments with high H2S and CO2 content was studied through high-temperature and high-pressure autoclave, and the HaS stress corrosion cracking （SSC） resistance o...The corrosion behavior of C100 steel in simulated environments with high H2S and CO2 content was studied through high-temperature and high-pressure autoclave, and the HaS stress corrosion cracking （SSC） resistance of C100 steel was evaluated by SSC tests. Scanning electron microscopy （SEM）, transmission electron microscope （TEM） and X-ray diffraction （XRD） technique were employed to characterize the corrosion products and the metal matrix. The results indicate that all of the corrosion products in this investigation are mainly composed of different types of iron sulfide such as Fe0.95S, FeS0.9, F0.985S, Fe7S8 and FeS, and the absence of iron carbonate in the corrosion scales suggests that the corrosion process is governed by H2S corrosion. The corrosion rate decreases in the initial stage and then increases with the enhancement of the temperature. There exists a minimum corrosion rate at about 110 ℃. Under the partial pressure of H2S lower than 9 MPa, the corrosion rate decreases with the increase of P112S While over 9 MPa, a higher P112S will result in a faster corrosion process. When the applied stress is 72%, 80% and 85% of actual yield strength （AYS）, all tested specimens show no crack, which reveals a superior SSC resistance.展开更多
In the present work, the susceptibility of API 5L X52 steel to corrosion processes was evaluated in the presence of high contents of hydrogen sulfide and carbon dioxide. Gravimetric tests and surface analyses were car...In the present work, the susceptibility of API 5L X52 steel to corrosion processes was evaluated in the presence of high contents of hydrogen sulfide and carbon dioxide. Gravimetric tests and surface analyses were carried out to establish both the corrosion rate and damage type exhibited by the metal. The obtained results indicate that the hydrogen sulfide is the most active gas in the corrosion processes that took place, quite above carbon dioxide. The main observed corrosion products were iron sulfides and the typical damage associated with hydrogen sulfide presence was Sulfide Stress Cracking (SSC). The surface damage evidences the presence of cracks with considerable magnitude and metal loss as consequences of the corrosion processes. Likewise, the presence of oxygen in the system modifies the displayed corrosion type, where corrosion products such as iron oxides and reduction in the number and extent of cracks are observed. On the other hand, the addition of a film-forming corrosion inhibitor based on modified imidazolines eliminates completely the development of cracks, although under certain test conditions, it can favor localized pitting corrosion.展开更多
The gene AtCSR encodes peptidyl-prolyl cis/trans isomerases (PPIases) that accelerate energetically unfavorable cis/trans isomerization of the peptide bond preceding proline production.In our studies,we found that AtC...The gene AtCSR encodes peptidyl-prolyl cis/trans isomerases (PPIases) that accelerate energetically unfavorable cis/trans isomerization of the peptide bond preceding proline production.In our studies,we found that AtCSR was associated with cadmium (Cd)-sensitive response in Arabidopsis.Our results show that AtCSR expression was triggered by Cd-stress in wild type Arabidopsis.The expression of some genes responsible for Cd2+ transportation into vacuoles was induced,and the expression of the iron-regulated transporter 1 (IRT1) related to Cd2+ absorption from the environment was not induced in wild type with Cd2+ treatment.The expression of Cd-transportation related genes was not in response to Cd-stress,whereas IRT expression increased dramatically in atcsr-2 with Cd2+ treatment.The expression of glutathione 1 (GSH1) was consistent with GSH being much lower in atcsr-2 in comparison with the wild type with Cd2+ treatment.Additionally,malondialdehyde (MDA),hydrogen peroxide,and Cd2+ contents,and activities of some antioxidative enzymes,differed between the wild type and atcsr-2.Hydrogen sulfide (H2S) has been confirmed as the third gas-transmitter over recent years.The findings revealed that the expression pattern of H2 S-releasing related genes and that of Cd-induced chelation and transportation genes matched well in the wild type and atcsr-2,and H2S could regulate the expression of the Cd-induced genes and alleviate Cd-triggered toxicity.Finally,one possible suggestion was given:down-regulation of atcsr-2,depending on H2S gas-transmitter not only weakened Cd2+ chelation,but also reduced Cd2+ transportation into vacuoles,as well as enhancing the Cd2+ assimilation,thus rendering atcsr-2 mutant sensitive to Cd-stress.展开更多
文摘cDNA libraries were constructed from the leaves of a rice (Oryza sativa L.) salt tolerancevariety Tesan抋i 2 growing in solutions with 150 mmol/L NaCl for 3 h or without salt stress. Three salt-responsive cDNA clones, Ts1, Ts2 and Ts3 were isolated by differential screening. Northern blottinganalysis showed that the transcription levels of Ts1 and Ts2 increased within 3 h salt stress and kept onincreasing within 24 h, while the transcription level of Ts3 reached its peak within 3 h. Sequence analysisindicated that there were no homologies between the three cDNA clones and any known gene. The threecDNA clones were mapped using a doubled haploid (DH) population derived from an indica variety ZYQ8,which was a salt tolerance parent of Tesan抋i 2, with a japonica variety JX17. Ts1, Ts2 and Ts3 werelocated on chromosomes 1, 3 and 7, respectively. It was noted that Ts1, Ts2, and Ts3 were in or near theregions of major or minor salt tolerance quantitative trait loci (QTLs), which were mapped in the same DHpopulation in a parallel study.
基金Funded by Key National Science&Technology Specific Projects(No.2008ZX05017-002)
文摘The corrosion behavior of C100 steel in simulated environments with high H2S and CO2 content was studied through high-temperature and high-pressure autoclave, and the HaS stress corrosion cracking （SSC） resistance of C100 steel was evaluated by SSC tests. Scanning electron microscopy （SEM）, transmission electron microscope （TEM） and X-ray diffraction （XRD） technique were employed to characterize the corrosion products and the metal matrix. The results indicate that all of the corrosion products in this investigation are mainly composed of different types of iron sulfide such as Fe0.95S, FeS0.9, F0.985S, Fe7S8 and FeS, and the absence of iron carbonate in the corrosion scales suggests that the corrosion process is governed by H2S corrosion. The corrosion rate decreases in the initial stage and then increases with the enhancement of the temperature. There exists a minimum corrosion rate at about 110 ℃. Under the partial pressure of H2S lower than 9 MPa, the corrosion rate decreases with the increase of P112S While over 9 MPa, a higher P112S will result in a faster corrosion process. When the applied stress is 72%, 80% and 85% of actual yield strength （AYS）, all tested specimens show no crack, which reveals a superior SSC resistance.
文摘In the present work, the susceptibility of API 5L X52 steel to corrosion processes was evaluated in the presence of high contents of hydrogen sulfide and carbon dioxide. Gravimetric tests and surface analyses were carried out to establish both the corrosion rate and damage type exhibited by the metal. The obtained results indicate that the hydrogen sulfide is the most active gas in the corrosion processes that took place, quite above carbon dioxide. The main observed corrosion products were iron sulfides and the typical damage associated with hydrogen sulfide presence was Sulfide Stress Cracking (SSC). The surface damage evidences the presence of cracks with considerable magnitude and metal loss as consequences of the corrosion processes. Likewise, the presence of oxygen in the system modifies the displayed corrosion type, where corrosion products such as iron oxides and reduction in the number and extent of cracks are observed. On the other hand, the addition of a film-forming corrosion inhibitor based on modified imidazolines eliminates completely the development of cracks, although under certain test conditions, it can favor localized pitting corrosion.
基金Project supported by the Research Fund for the Doctoral Program of Higher Education of China (No. 20091401110004)the Science and Technology Special Project of Shanxi Province,China (2012,to QiangZHANG)the Shanxi Scholarship Council of China (No. 2011-007)
文摘The gene AtCSR encodes peptidyl-prolyl cis/trans isomerases (PPIases) that accelerate energetically unfavorable cis/trans isomerization of the peptide bond preceding proline production.In our studies,we found that AtCSR was associated with cadmium (Cd)-sensitive response in Arabidopsis.Our results show that AtCSR expression was triggered by Cd-stress in wild type Arabidopsis.The expression of some genes responsible for Cd2+ transportation into vacuoles was induced,and the expression of the iron-regulated transporter 1 (IRT1) related to Cd2+ absorption from the environment was not induced in wild type with Cd2+ treatment.The expression of Cd-transportation related genes was not in response to Cd-stress,whereas IRT expression increased dramatically in atcsr-2 with Cd2+ treatment.The expression of glutathione 1 (GSH1) was consistent with GSH being much lower in atcsr-2 in comparison with the wild type with Cd2+ treatment.Additionally,malondialdehyde (MDA),hydrogen peroxide,and Cd2+ contents,and activities of some antioxidative enzymes,differed between the wild type and atcsr-2.Hydrogen sulfide (H2S) has been confirmed as the third gas-transmitter over recent years.The findings revealed that the expression pattern of H2 S-releasing related genes and that of Cd-induced chelation and transportation genes matched well in the wild type and atcsr-2,and H2S could regulate the expression of the Cd-induced genes and alleviate Cd-triggered toxicity.Finally,one possible suggestion was given:down-regulation of atcsr-2,depending on H2S gas-transmitter not only weakened Cd2+ chelation,but also reduced Cd2+ transportation into vacuoles,as well as enhancing the Cd2+ assimilation,thus rendering atcsr-2 mutant sensitive to Cd-stress.
