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Annealienor Very - One of the best experts on this subject based on the ideXlab platform.
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constitutive contribution by the rice oshkt1 4 na transporter to xylem sap Desalinization and low na accumulation in young leaves under low as high external na conditions
Frontiers in Plant Science, 2020Co-Authors: Imran Khan, Sonia Mohamed, Thomas Regnault, Delphine Mieulet, Emmanuel Guiderdoni, Herve Sentenac, Annealienor VeryAbstract:HKT Na+ transporters correspond to major salt tolerance QTLs in different plant species and are targets of great interest for breeders. In rice, the HKT family is composed of seven or eight functional genes depending on cultivars. Three rice HKT genes, OsHKT1;1, OsHKT1;4 and OsHKT1;5, are known to contribute to salt tolerance by reducing Na+ accumulation in shoots upon salt stress. Here, we further investigate the mechanisms by which OsHKT1;4 contributes to this process and extend this analysis to the role of this transporter in plants in presence of low Na+ concentrations. By analyzing transgenic rice plants expressing a GUS reporter gene construct, we observed that OsHKT1;4 is mainly expressed in xylem parenchyma in both roots and leaves. Using mutant lines expressing artificial microRNA that selectively reduced OsHKT1;4 expression, the involvement of OsHKT1;4 in retrieving Na+ from the xylem sap in the roots upon salt stress was evidenced. Since OsHKT1;4 was found to be also well expressed in the roots in absence of salt stress, we extended the analysis of its role when plants were subjected to non-toxic Na+ conditions (0.5 and 5 mM). Our finding that the transporter, expressed in Xenopus oocytes, displayed a relatively high affinity for Na+, just above 1 mM, provided first support to the hypothesis that OsHKT1;4 could have a physiological role at low Na+ concentrations. We observed that progressive Desalinization of the xylem sap along its ascent to the leaf blades still occurred in plants grown at submillimolar Na+ concentration, and that OsHKT1;4 was involved in reducing xylem sap Na+ concentration in roots in these conditions too. Its contribution to tissue Desalinization from roots to young mature leaf blades appeared to be rather similar in the whole range of explored external Na+ concentrations, from submillimolar to salt stress conditions. Our data therefore indicate that HKT transporters can be involved in controlling Na+ translocation from roots to shoots in a much wider range of Na+ concentrations than previously thought. This asks questions about the roles of such a transporter-mediated maintaining of tissue Na+ content gradients in non-toxic conditions.
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Constitutive Contribution by the Rice OsHKT1;4 Na+ Transporter to Xylem Sap Desalinization and Low Na+ Accumulation in Young Leaves Under Low as High External Na+ Conditions
Frontiers in Plant Science, 2020Co-Authors: Imran Khan, Sonia Mohamed, Thomas Regnault, Delphine Mieulet, Emmanuel Guiderdoni, Herve Sentenac, Annealienor VeryAbstract:HKT Na+ transporters correspond to major salt tolerance QTLs in different plant species and are targets of great interest for breeders. In rice, the HKT family is composed of seven or eight functional genes depending on cultivars. Three rice HKT genes, OsHKT1;1, OsHKT1;4 and OsHKT1;5, are known to contribute to salt tolerance by reducing Na+ accumulation in shoots upon salt stress. Here, we further investigate the mechanisms by which OsHKT1;4 contributes to this process and extend this analysis to the role of this transporter in plants in presence of low Na+ concentrations. By analyzing transgenic rice plants expressing a GUS reporter gene construct, we observed that OsHKT1;4 is mainly expressed in xylem parenchyma in both roots and leaves. Using mutant lines expressing artificial microRNA that selectively reduced OsHKT1;4 expression, the involvement of OsHKT1;4 in retrieving Na+ from the xylem sap in the roots upon salt stress was evidenced. Since OsHKT1;4 was found to be also well expressed in the roots in absence of salt stress, we extended the analysis of its role when plants were subjected to non-toxic Na+ conditions (0.5 and 5 mM). Our finding that the transporter, expressed in Xenopus oocytes, displayed a relatively high affinity for Na+, just above 1 mM, provided first support to the hypothesis that OsHKT1;4 could have a physiological role at low Na+ concentrations. We observed that progressive Desalinization of the xylem sap along its ascent to the leaf blades still occurred in plants grown at submillimolar Na+ concentration, and that OsHKT1;4 was involved in reducing xylem sap Na+ concentration in roots in these conditions too. Its contribution to tissue Desalinization from roots to young mature leaf blades appeared to be rather similar in the whole range of explored external Na+ concentrations, from submillimolar to salt stress conditions. Our data therefore indicate that HKT transporters can be involved in controlling Na+ translocation from roots to shoots in a much wider range of Na+ concentrations than previously thought. This asks questions about the roles of such a transporter-mediated maintaining of tissue Na+ content gradients in non-toxic conditions.
Ahmad Bakour - One of the best experts on this subject based on the ideXlab platform.
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effects of saline water irrigation on soil salinity and yield of summer maize zea mays l in subsurface drainage system
Agricultural Water Management, 2017Co-Authors: Genxiang Feng, Zhanyu Zhang, Peirong Lu, Ahmad BakourAbstract:Sustainable development of saline water irrigation was restricted by salt accumulation in the soil profile without appropriate salt discharging measures. A two year study was conducted in 2014 and 2015 to identify the effect of saline water irrigation on soil salt and maize yield under subsurface drainage system. The treatments of this study comprised three levels of water salinity with 0.78, 3.75, and 6.25dSm−1 (S1–S3) and three levels of subsurface drainage depth with no subsurface drainage, drain depth of 0.8m and 1.2m (D0–D2). Results indicated that the average salt content within the root zone was in the order of D0>D2>D1. No salt accumulation occurred during the two growing seasons under D1, but there was salt accumulation under D2S3. Soil Desalinization efficiency reduced with the increasing of irrigation water salinity, and the average Desalinization efficiency for D1 was higher than that of D0 and D2. Maize yield and water use efficiency decreased with the increase of water salinity. The yield decreased by 2.08–3.01% for every 1dSm−1 increase in salinity level of irrigation water under D1, and 3.53–3.93% for every 1dSm−1 under D2. The effects of water salinity and drainage depth on maize yield and WUE were significant (p<0.05) in the two growing seasons. From the view points of relative yield and soil salt balance, it can be recognized even as the salinity level of irrigation water is as high as 6.25dSm−1, saline water can be applied to irrigate maize under drain depth of 0.8m.
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effects of saline water irrigation on soil salinity and yield of summer maize zea mays l in subsurface drainage system
Agricultural Water Management, 2017Co-Authors: Genxiang Feng, Zhanyu Zhang, Changyu Wan, Ahmad BakourAbstract:Abstract Sustainable development of saline water irrigation was restricted by salt accumulation in the soil profile without appropriate salt discharging measures. A two year study was conducted in 2014 and 2015 to identify the effect of saline water irrigation on soil salt and maize yield under subsurface drainage system. The treatments of this study comprised three levels of water salinity with 0.78, 3.75, and 6.25 dS m −1 (S1–S3) and three levels of subsurface drainage depth with no subsurface drainage, drain depth of 0.8 m and 1.2 m (D0–D2). Results indicated that the average salt content within the root zone was in the order of D0 > D2 > D1. No salt accumulation occurred during the two growing seasons under D1, but there was salt accumulation under D2S3. Soil Desalinization efficiency reduced with the increasing of irrigation water salinity, and the average Desalinization efficiency for D1 was higher than that of D0 and D2. Maize yield and water use efficiency decreased with the increase of water salinity. The yield decreased by 2.08–3.01% for every 1 dS m −1 increase in salinity level of irrigation water under D1, and 3.53–3.93% for every 1 dS m −1 under D2. The effects of water salinity and drainage depth on maize yield and WUE were significant (p −1 , saline water can be applied to irrigate maize under drain depth of 0.8 m.
Imran Khan - One of the best experts on this subject based on the ideXlab platform.
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constitutive contribution by the rice oshkt1 4 na transporter to xylem sap Desalinization and low na accumulation in young leaves under low as high external na conditions
Frontiers in Plant Science, 2020Co-Authors: Imran Khan, Sonia Mohamed, Thomas Regnault, Delphine Mieulet, Emmanuel Guiderdoni, Herve Sentenac, Annealienor VeryAbstract:HKT Na+ transporters correspond to major salt tolerance QTLs in different plant species and are targets of great interest for breeders. In rice, the HKT family is composed of seven or eight functional genes depending on cultivars. Three rice HKT genes, OsHKT1;1, OsHKT1;4 and OsHKT1;5, are known to contribute to salt tolerance by reducing Na+ accumulation in shoots upon salt stress. Here, we further investigate the mechanisms by which OsHKT1;4 contributes to this process and extend this analysis to the role of this transporter in plants in presence of low Na+ concentrations. By analyzing transgenic rice plants expressing a GUS reporter gene construct, we observed that OsHKT1;4 is mainly expressed in xylem parenchyma in both roots and leaves. Using mutant lines expressing artificial microRNA that selectively reduced OsHKT1;4 expression, the involvement of OsHKT1;4 in retrieving Na+ from the xylem sap in the roots upon salt stress was evidenced. Since OsHKT1;4 was found to be also well expressed in the roots in absence of salt stress, we extended the analysis of its role when plants were subjected to non-toxic Na+ conditions (0.5 and 5 mM). Our finding that the transporter, expressed in Xenopus oocytes, displayed a relatively high affinity for Na+, just above 1 mM, provided first support to the hypothesis that OsHKT1;4 could have a physiological role at low Na+ concentrations. We observed that progressive Desalinization of the xylem sap along its ascent to the leaf blades still occurred in plants grown at submillimolar Na+ concentration, and that OsHKT1;4 was involved in reducing xylem sap Na+ concentration in roots in these conditions too. Its contribution to tissue Desalinization from roots to young mature leaf blades appeared to be rather similar in the whole range of explored external Na+ concentrations, from submillimolar to salt stress conditions. Our data therefore indicate that HKT transporters can be involved in controlling Na+ translocation from roots to shoots in a much wider range of Na+ concentrations than previously thought. This asks questions about the roles of such a transporter-mediated maintaining of tissue Na+ content gradients in non-toxic conditions.
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Constitutive Contribution by the Rice OsHKT1;4 Na+ Transporter to Xylem Sap Desalinization and Low Na+ Accumulation in Young Leaves Under Low as High External Na+ Conditions
Frontiers in Plant Science, 2020Co-Authors: Imran Khan, Sonia Mohamed, Thomas Regnault, Delphine Mieulet, Emmanuel Guiderdoni, Herve Sentenac, Annealienor VeryAbstract:HKT Na+ transporters correspond to major salt tolerance QTLs in different plant species and are targets of great interest for breeders. In rice, the HKT family is composed of seven or eight functional genes depending on cultivars. Three rice HKT genes, OsHKT1;1, OsHKT1;4 and OsHKT1;5, are known to contribute to salt tolerance by reducing Na+ accumulation in shoots upon salt stress. Here, we further investigate the mechanisms by which OsHKT1;4 contributes to this process and extend this analysis to the role of this transporter in plants in presence of low Na+ concentrations. By analyzing transgenic rice plants expressing a GUS reporter gene construct, we observed that OsHKT1;4 is mainly expressed in xylem parenchyma in both roots and leaves. Using mutant lines expressing artificial microRNA that selectively reduced OsHKT1;4 expression, the involvement of OsHKT1;4 in retrieving Na+ from the xylem sap in the roots upon salt stress was evidenced. Since OsHKT1;4 was found to be also well expressed in the roots in absence of salt stress, we extended the analysis of its role when plants were subjected to non-toxic Na+ conditions (0.5 and 5 mM). Our finding that the transporter, expressed in Xenopus oocytes, displayed a relatively high affinity for Na+, just above 1 mM, provided first support to the hypothesis that OsHKT1;4 could have a physiological role at low Na+ concentrations. We observed that progressive Desalinization of the xylem sap along its ascent to the leaf blades still occurred in plants grown at submillimolar Na+ concentration, and that OsHKT1;4 was involved in reducing xylem sap Na+ concentration in roots in these conditions too. Its contribution to tissue Desalinization from roots to young mature leaf blades appeared to be rather similar in the whole range of explored external Na+ concentrations, from submillimolar to salt stress conditions. Our data therefore indicate that HKT transporters can be involved in controlling Na+ translocation from roots to shoots in a much wider range of Na+ concentrations than previously thought. This asks questions about the roles of such a transporter-mediated maintaining of tissue Na+ content gradients in non-toxic conditions.
Yu-jun Cui - One of the best experts on this subject based on the ideXlab platform.
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swelling deformation of compacted gmz bentonite experiencing chemical cycles of sodium calcium exchange and salinization Desalinization effect
Applied Clay Science, 2017Co-Authors: Yu-jun Cui, Yonggui Chen, Lingyan Jia, Bao ChenAbstract:Abstract In China, GMZ bentonite has been recognized as the first choice of buffer material while Beishan area in Gansu province has been considered as the potential disposal site for high-level radioactive waste (HLW) repository. As the groundwater at the repository field is rich in Na + and Ca 2 + , the swelling properties of compacted GMZ bentonite will be affected by the chemistry of groundwater. In this work, the swelling deformation behaviors of compacted GMZ bentonite were tested at a vertical stress of 0.1 MPa to assess the influence of cation exchange between Na + and Ca 2 + , as well as the salinization-Desalinization effect by cyclical infiltrations of distilled water and saline solutions. Results show that Na-bentonite is partly transformed into Ca-bentonite once NaCl solution is replaced with CaCl 2 solution. Comparing to NaCl solution, the inhibiting effect of CaCl 2 solution is weak, and thus the additional swelling is observed. Along with chemical cycles, the total strain of compacted GMZ bentonite gradually increases, while the chemical sensitivity of strain behavior reduces. This tendency is also detected for GMZ bentonite experiencing the Desalinization path of distilled water prior to each infiltration of salt solution. Regarding the relative strain of GMZ bentonite, the difference in osmotic suction between distilled water and salt solution is more relevant than the sodium-calcium replacement.
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influences of salt solutions and salinization Desalinization processes on the volume change of compacted gmz01 bentonite
Engineering Geology, 2017Co-Authors: Feng Zhang, Yu-jun Cui, Yonggui Chen, Bao ChenAbstract:Abstract Investigation on influences of cyclic salinization-Desalinization processes on clay is of great importance for evaluation of the behavior of engineering barrier in deep geological repository for disposal of high-level radioactive waste. In this study, one-dimensional free swelling tests were conducted on densely compacted GMZ01 bentonite specimens, which has an initial dry density of 1.7 Mg/m 3 , with cyclically infiltration of NaCl, CaCl 2 or KCl solution at different concentrations and de-ionized water. Results show that the volume change of the compacted clay could be influenced by concentrations and cation types of solutions, as well as number of salinization-Desalinization cycles during the salinization-Desalinization processes. The total swelling strain of GMZ01 bentonite specimens measured on the first salinization with salt solutions at a same concentration follows an order: NaCl > CaCl 2 > KCl. This observation could be explained by the influences of basal space, DDL theory and K-linkage. A cation with higher replacing power can be replaced by another cation with lower replacing capacity when it has a higher concentration in the pore solution. The concentration effect on the swelling behavior of GMZ01 bentonite was explained using the concept of osmotic suction for specimens initially infiltrated with NaCl solutions. For specimens initially infiltrated with CaCl 2 solutions, in addition to the osmotic suction effect, the distance between the unit layers of montmorillonite also played a role in explaining the swelling behavior. The swelling behavior of specimens initially infiltrated with KCl solutions could be explained by the strong K-linkage.
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Swelling pressure and hydraulic conductivity of compacted GMZ01 bentonite under salinization-Desalinization cycle conditions
Applied Clay Science, 2015Co-Authors: Y.g. Chen, Chunming Zhu, Qiong Wang, Yu-jun CuiAbstract:Compacted bentonite has been used as buffer material in radioactive waste disposal. Once compacted bentonite is emplaced, the chemical composition of site water is changed due to the long-term interaction between the bentonite, surrounding rock and the concrete facility; therefore the hydraulic mechanical behavior of compacted bentonite should be evaluated for the disposal safety. In this study, the swelling pressure and hydraulic conductivity of compacted GMZ01 bentonite were investigated under salinization Desalinization chemical cycles using a newly developed apparatus. Results show that the salinization process leads a reducing of swelling pressure and the desalination process leads to an increasing of swelling pressure; the hydraulic conductivity increases in the salinization process while decreases in the Desalinization process. The variation magnitude of the swelling pressure and hydraulic conductivity is related to the solution concentration applied. Meanwhile, the initial chemical condition and chemical cycle paths have a significant effect in the swelling characteristics and hydraulic properties. Since the salinization-Desalinization cycle is expected to occur over a long time during the operation of the repository, the monitoring of the buffer materials will be important for the disposal safety.
Delphine Mieulet - One of the best experts on this subject based on the ideXlab platform.
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constitutive contribution by the rice oshkt1 4 na transporter to xylem sap Desalinization and low na accumulation in young leaves under low as high external na conditions
Frontiers in Plant Science, 2020Co-Authors: Imran Khan, Sonia Mohamed, Thomas Regnault, Delphine Mieulet, Emmanuel Guiderdoni, Herve Sentenac, Annealienor VeryAbstract:HKT Na+ transporters correspond to major salt tolerance QTLs in different plant species and are targets of great interest for breeders. In rice, the HKT family is composed of seven or eight functional genes depending on cultivars. Three rice HKT genes, OsHKT1;1, OsHKT1;4 and OsHKT1;5, are known to contribute to salt tolerance by reducing Na+ accumulation in shoots upon salt stress. Here, we further investigate the mechanisms by which OsHKT1;4 contributes to this process and extend this analysis to the role of this transporter in plants in presence of low Na+ concentrations. By analyzing transgenic rice plants expressing a GUS reporter gene construct, we observed that OsHKT1;4 is mainly expressed in xylem parenchyma in both roots and leaves. Using mutant lines expressing artificial microRNA that selectively reduced OsHKT1;4 expression, the involvement of OsHKT1;4 in retrieving Na+ from the xylem sap in the roots upon salt stress was evidenced. Since OsHKT1;4 was found to be also well expressed in the roots in absence of salt stress, we extended the analysis of its role when plants were subjected to non-toxic Na+ conditions (0.5 and 5 mM). Our finding that the transporter, expressed in Xenopus oocytes, displayed a relatively high affinity for Na+, just above 1 mM, provided first support to the hypothesis that OsHKT1;4 could have a physiological role at low Na+ concentrations. We observed that progressive Desalinization of the xylem sap along its ascent to the leaf blades still occurred in plants grown at submillimolar Na+ concentration, and that OsHKT1;4 was involved in reducing xylem sap Na+ concentration in roots in these conditions too. Its contribution to tissue Desalinization from roots to young mature leaf blades appeared to be rather similar in the whole range of explored external Na+ concentrations, from submillimolar to salt stress conditions. Our data therefore indicate that HKT transporters can be involved in controlling Na+ translocation from roots to shoots in a much wider range of Na+ concentrations than previously thought. This asks questions about the roles of such a transporter-mediated maintaining of tissue Na+ content gradients in non-toxic conditions.
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Constitutive Contribution by the Rice OsHKT1;4 Na+ Transporter to Xylem Sap Desalinization and Low Na+ Accumulation in Young Leaves Under Low as High External Na+ Conditions
Frontiers in Plant Science, 2020Co-Authors: Imran Khan, Sonia Mohamed, Thomas Regnault, Delphine Mieulet, Emmanuel Guiderdoni, Herve Sentenac, Annealienor VeryAbstract:HKT Na+ transporters correspond to major salt tolerance QTLs in different plant species and are targets of great interest for breeders. In rice, the HKT family is composed of seven or eight functional genes depending on cultivars. Three rice HKT genes, OsHKT1;1, OsHKT1;4 and OsHKT1;5, are known to contribute to salt tolerance by reducing Na+ accumulation in shoots upon salt stress. Here, we further investigate the mechanisms by which OsHKT1;4 contributes to this process and extend this analysis to the role of this transporter in plants in presence of low Na+ concentrations. By analyzing transgenic rice plants expressing a GUS reporter gene construct, we observed that OsHKT1;4 is mainly expressed in xylem parenchyma in both roots and leaves. Using mutant lines expressing artificial microRNA that selectively reduced OsHKT1;4 expression, the involvement of OsHKT1;4 in retrieving Na+ from the xylem sap in the roots upon salt stress was evidenced. Since OsHKT1;4 was found to be also well expressed in the roots in absence of salt stress, we extended the analysis of its role when plants were subjected to non-toxic Na+ conditions (0.5 and 5 mM). Our finding that the transporter, expressed in Xenopus oocytes, displayed a relatively high affinity for Na+, just above 1 mM, provided first support to the hypothesis that OsHKT1;4 could have a physiological role at low Na+ concentrations. We observed that progressive Desalinization of the xylem sap along its ascent to the leaf blades still occurred in plants grown at submillimolar Na+ concentration, and that OsHKT1;4 was involved in reducing xylem sap Na+ concentration in roots in these conditions too. Its contribution to tissue Desalinization from roots to young mature leaf blades appeared to be rather similar in the whole range of explored external Na+ concentrations, from submillimolar to salt stress conditions. Our data therefore indicate that HKT transporters can be involved in controlling Na+ translocation from roots to shoots in a much wider range of Na+ concentrations than previously thought. This asks questions about the roles of such a transporter-mediated maintaining of tissue Na+ content gradients in non-toxic conditions.