Populus euphratica Oliv. is of high salinity tolerance and used as a model species for investigating molecular mechanisms of trees＇ responses to salt stress. In the work presented here we found that calli of P. euphr...Populus euphratica Oliv. is of high salinity tolerance and used as a model species for investigating molecular mechanisms of trees＇ responses to salt stress. In the work presented here we found that calli of P. euphratica grew more rapidly and accumulated less Na＋, but more K＋, under salt stress than those of salt-sensitive poplar, Populus hopeiensis. Different types of Na＋/H＋ antiporters （SOS1, NhaD1 and NHX1） were isolated from P. euphratica; all of these genes have been shown to play important roles in plant salt tolerance mechanism in previous studies. Expression profiles of these three genes were compared between P. hopeiensis and P. euphratica in the presence and absence of salt stress by real-time PCR. The three genes were induced in both P. euphratica and P. hopeiensis by salt. Transcript levels of PeNHX1 were lower in P. euphratica than in P. hopeiensis under 150 mM NaCl stress. In addition, transcript levels of PeNhaD1 were lower, while PeSOS1 were higher in P. euphratica than in P. hopeiensis under both stressed and unstressed conditions. The results indicated that P. euphratica up-regulates different genes and consistently maintains both effluxes of Na＋ and high K＋ levels. Our data suggests that differences in gene expression patterns may contribute to the dif-ference in salt tolerance between these two poplars.展开更多
Arabidopsis plastid antiporters KEA1 and KEA2are critical for plastid development, photosynthetic efficiency, and plant development.Here, we show that KEA1 and KEA2 are involved in vacuolar protein trafficking. Geneti...Arabidopsis plastid antiporters KEA1 and KEA2are critical for plastid development, photosynthetic efficiency, and plant development.Here, we show that KEA1 and KEA2 are involved in vacuolar protein trafficking. Genetic analyses found that the kea1 kea2 mutants had short siliques, small seeds, and short seedlings. Molecular and biochemical assays showed that seed storage proteins were missorted out of the cell and the precursor proteins were accumulated in kea1 kea2. Protein storage vacuoles(PSVs) were smaller in kea1 kea2. Further analyses showed that endosomal trafficking in kea1 kea2 was compromised. Vacuolar sorting receptor 1(VSR1) subcellular localizations, VSR–cargo interactions, and p24 distribution on the endoplasmic reticulum(ER) and Golgi apparatus were affected in kea1 kea2. Moreover, plastid stromule growth was reduced and plastid association with the endomembrane compartments was disrupted in kea1 kea2. Stromule growth was regulated by the cellular pH and K+homeostasis maintained by KEA1 and KEA2. The organellar pH along the trafficking pathway was altered in kea1 kea2. Overall, KEA1 and KEA2 regulate vacuolar trafficking by controlling the function of plastid stromules via adjusting pH and K+homeostasis.展开更多
Salinity is one of the most critical environmental problems, which causes plant growth retardation by disturbing intracellular ion homeostasis. The Na+/H+ antiporter plays an important role in resistance to salt stres...Salinity is one of the most critical environmental problems, which causes plant growth retardation by disturbing intracellular ion homeostasis. The Na+/H+ antiporter plays an important role in resistance to salt stress by sequestering Na+ in exchange for H+ across the vacuolar membranes. In the current study, the coding regions of two Arabidopsis antiporters (AtNHX1 and AtNHX2) and one rice antiporter (OsNHX1) were amplified by target specific PCR. PCR amplicons were first cloned into pENTR/D-TOPO and later recombined with a destination vector (pK7WG2.0) by LR reaction. Positive clones were selected by PCR, restriction digestion (RD) and sequencing. They were then transformed into Agrobacterium tumefaciens (LBA4404 strain) for subsequent transformation of farmer popular tomato varieties.展开更多
Populus euphratica and Populuspruinosa, sister species in the Turanga Section （Salicaceae）, growing in semi-arid saline areas are known for their high salinity tolerance. In this study, by combining growth level wit...Populus euphratica and Populuspruinosa, sister species in the Turanga Section （Salicaceae）, growing in semi-arid saline areas are known for their high salinity tolerance. In this study, by combining growth level with Na＋ and K＋ contents, the expression level of vacuolar Na＋/H＋ antiporters was investigated for NaCl-induced changes in P. euphratica and t3. pru- inosa calli. Compared to R euphratica, P. pruinosa calli grew well in 200 mM NaC1 stress from 14. to 21 days. Increasing the stressed time caused an increase in Na＋ content concomitant with a decrease in K＋ content in P. euphratica calli, whereas, with the presence of 200 mM NaCI, K＋ content has a less increase in 14 and 21 days than in 7 days which was detected in R pruinosa calli. The transcript levels of six genes coding for NHX-type Na＋/H＋ antiporters suggest that vacuolar NHX1-NHX6 antiporters play important roles in responding to salt stress in R pruinosa. Our data suggest that there exists a higher salt tolerance for P. pruinosa than P. euphratica at the cellular level, Na＋ avoidance or accumulation is observed in cellular compartments, and that expression of NHX antiporters is linked to the accumulator phenotype.展开更多
The plant vacuole plays a fundamental role in cell homeostasis.The successful application of patch-clamp tech-nique on isolated vacuoles allows the determination of the functional characteristics of tonoplast ion chan...The plant vacuole plays a fundamental role in cell homeostasis.The successful application of patch-clamp tech-nique on isolated vacuoles allows the determination of the functional characteristics of tonoplast ion channels and transporters.The parallel use of a sensor-based fluorescence approach capable of detecting changes in calcium and proton concentrations opens up new possibilities for investigation.In excised patch,the presence of fura-2 in the vacuolar solution reveals the direct permeation of calcium in plant TPC channels.In whole-vacuole,the activity of non-electrogenic NHX potassium proton antiporters can be measured by using the proton sensitive dye BCECF loaded in the vacuolar lumen by the patch pipette.Both vacuolar NHXs and CLCa(chloride/nitrate antiporter)are inhibited by the phosphoinositide PI(3,5)P2,suggesting a coordinated role of these proteins in salt accumulation.Increased knowledge in the molecular mechanisms of vacuolar ion channels and transporters has the potential to improve our understanding on how plants cope with a rapidly changing environment.展开更多
Na+/H+逆向转运蛋白具有调节细胞内离子浓度及维持pH值稳定的作用,是植物抵御盐胁迫的重要因子。从盐角草RNA-Seq数据中筛选Na+/H+逆向转运蛋白序列,利用生物信息学手段,拼接得到5条Na+/H+逆向转运蛋白完整cDNA序列,通过与NCBI已有序列...Na+/H+逆向转运蛋白具有调节细胞内离子浓度及维持pH值稳定的作用,是植物抵御盐胁迫的重要因子。从盐角草RNA-Seq数据中筛选Na+/H+逆向转运蛋白序列,利用生物信息学手段,拼接得到5条Na+/H+逆向转运蛋白完整cDNA序列,通过与NCBI已有序列比对分析,将其命名为SeNHX1、SeNHX3、SeNHX4、SeNHX5和SeNhaD。考察盐角草Na+/H+逆向转运蛋白在两种盐分变化情况下的表达变化:1)从无盐处理转移到200 mM NaCl处理;2)从200 mM NaCl培养基转移到无盐培养基。结果表明:SeNHX4的表达量非常低,在地下部几乎检测不到;SeNhaD在地上部的表达量是地下部的2倍左右,说明NhaD主要在盐角草地上部发挥作用;SeNHX1、SeNHX3和SeNHX5的表达量明显高于其他两个基因,对盐角草的耐盐机制起到更大的作用,并且SeNHX1和SeNHX5受盐分诱导表达,表达量与盐浓度呈正相关,可能在盐角草耐盐调控网络中发挥重要作用。综上,NHX基因家族和NhaD的表达量受到基质中盐分的调控作用,其表达在盐分处理或者盐分去除1~3 d后发生变化。研究结果有助于阐明盐角草NHX基因家族和NhaD对盐分的响应特点。展开更多
基金NSFC (30800865, 40801001)the Education Ministry of China (NCET-05-0886)China Postdoctoral Science Foundation (20070420758)
文摘Populus euphratica Oliv. is of high salinity tolerance and used as a model species for investigating molecular mechanisms of trees＇ responses to salt stress. In the work presented here we found that calli of P. euphratica grew more rapidly and accumulated less Na＋, but more K＋, under salt stress than those of salt-sensitive poplar, Populus hopeiensis. Different types of Na＋/H＋ antiporters （SOS1, NhaD1 and NHX1） were isolated from P. euphratica; all of these genes have been shown to play important roles in plant salt tolerance mechanism in previous studies. Expression profiles of these three genes were compared between P. hopeiensis and P. euphratica in the presence and absence of salt stress by real-time PCR. The three genes were induced in both P. euphratica and P. hopeiensis by salt. Transcript levels of PeNHX1 were lower in P. euphratica than in P. hopeiensis under 150 mM NaCl stress. In addition, transcript levels of PeNhaD1 were lower, while PeSOS1 were higher in P. euphratica than in P. hopeiensis under both stressed and unstressed conditions. The results indicated that P. euphratica up-regulates different genes and consistently maintains both effluxes of Na＋ and high K＋ levels. Our data suggests that differences in gene expression patterns may contribute to the dif-ference in salt tolerance between these two poplars.
基金supported by the National Natural Science Foundation of China (NSFC)(31571464, 31371438, 31070222 to Quan-Sheng Qiu)the National Basic Research Program of China (973)project, 2013CB429904 to Quan-Sheng Qiu)+5 种基金the Research Fund for the Doctoral Program of Higher Education of China(RFDP)(20130211110001 to Quan-Sheng Qiu)Research Team of Stress Tolerance Mechanisms and Molecular Breeding of Plateau PlantsQinghai Province “Kunlun Talents·Advanced Innovative and Entrepreneurial Talents” Program (2022 to QuanSheng Qiu)the Qinghai Provincial Department of Science and Technology Qinghai basic research program (2022-ZJ-724 to Quan-Sheng Qiu)the Independent Research and Development Project of State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems (202202 to Quan-Sheng Qiu)the Core Facility of School of Life Sciences,Lanzhou University。
文摘Arabidopsis plastid antiporters KEA1 and KEA2are critical for plastid development, photosynthetic efficiency, and plant development.Here, we show that KEA1 and KEA2 are involved in vacuolar protein trafficking. Genetic analyses found that the kea1 kea2 mutants had short siliques, small seeds, and short seedlings. Molecular and biochemical assays showed that seed storage proteins were missorted out of the cell and the precursor proteins were accumulated in kea1 kea2. Protein storage vacuoles(PSVs) were smaller in kea1 kea2. Further analyses showed that endosomal trafficking in kea1 kea2 was compromised. Vacuolar sorting receptor 1(VSR1) subcellular localizations, VSR–cargo interactions, and p24 distribution on the endoplasmic reticulum(ER) and Golgi apparatus were affected in kea1 kea2. Moreover, plastid stromule growth was reduced and plastid association with the endomembrane compartments was disrupted in kea1 kea2. Stromule growth was regulated by the cellular pH and K+homeostasis maintained by KEA1 and KEA2. The organellar pH along the trafficking pathway was altered in kea1 kea2. Overall, KEA1 and KEA2 regulate vacuolar trafficking by controlling the function of plastid stromules via adjusting pH and K+homeostasis.
文摘Salinity is one of the most critical environmental problems, which causes plant growth retardation by disturbing intracellular ion homeostasis. The Na+/H+ antiporter plays an important role in resistance to salt stress by sequestering Na+ in exchange for H+ across the vacuolar membranes. In the current study, the coding regions of two Arabidopsis antiporters (AtNHX1 and AtNHX2) and one rice antiporter (OsNHX1) were amplified by target specific PCR. PCR amplicons were first cloned into pENTR/D-TOPO and later recombined with a destination vector (pK7WG2.0) by LR reaction. Positive clones were selected by PCR, restriction digestion (RD) and sequencing. They were then transformed into Agrobacterium tumefaciens (LBA4404 strain) for subsequent transformation of farmer popular tomato varieties.
基金Financial support for this research was provided by the Program for New Century Excellent Talents in the Ministry of Education in China(NCET-09-0446),NSFC(31370396,30800865) and lzujbky-2012-k22 to YuXia Wu
文摘Populus euphratica and Populuspruinosa, sister species in the Turanga Section （Salicaceae）, growing in semi-arid saline areas are known for their high salinity tolerance. In this study, by combining growth level with Na＋ and K＋ contents, the expression level of vacuolar Na＋/H＋ antiporters was investigated for NaCl-induced changes in P. euphratica and t3. pru- inosa calli. Compared to R euphratica, P. pruinosa calli grew well in 200 mM NaC1 stress from 14. to 21 days. Increasing the stressed time caused an increase in Na＋ content concomitant with a decrease in K＋ content in P. euphratica calli, whereas, with the presence of 200 mM NaCI, K＋ content has a less increase in 14 and 21 days than in 7 days which was detected in R pruinosa calli. The transcript levels of six genes coding for NHX-type Na＋/H＋ antiporters suggest that vacuolar NHX1-NHX6 antiporters play important roles in responding to salt stress in R pruinosa. Our data suggest that there exists a higher salt tolerance for P. pruinosa than P. euphratica at the cellular level, Na＋ avoidance or accumulation is observed in cellular compartments, and that expression of NHX antiporters is linked to the accumulator phenotype.
文摘The plant vacuole plays a fundamental role in cell homeostasis.The successful application of patch-clamp tech-nique on isolated vacuoles allows the determination of the functional characteristics of tonoplast ion channels and transporters.The parallel use of a sensor-based fluorescence approach capable of detecting changes in calcium and proton concentrations opens up new possibilities for investigation.In excised patch,the presence of fura-2 in the vacuolar solution reveals the direct permeation of calcium in plant TPC channels.In whole-vacuole,the activity of non-electrogenic NHX potassium proton antiporters can be measured by using the proton sensitive dye BCECF loaded in the vacuolar lumen by the patch pipette.Both vacuolar NHXs and CLCa(chloride/nitrate antiporter)are inhibited by the phosphoinositide PI(3,5)P2,suggesting a coordinated role of these proteins in salt accumulation.Increased knowledge in the molecular mechanisms of vacuolar ion channels and transporters has the potential to improve our understanding on how plants cope with a rapidly changing environment.
文摘Na+/H+逆向转运蛋白具有调节细胞内离子浓度及维持pH值稳定的作用,是植物抵御盐胁迫的重要因子。从盐角草RNA-Seq数据中筛选Na+/H+逆向转运蛋白序列,利用生物信息学手段,拼接得到5条Na+/H+逆向转运蛋白完整cDNA序列,通过与NCBI已有序列比对分析,将其命名为SeNHX1、SeNHX3、SeNHX4、SeNHX5和SeNhaD。考察盐角草Na+/H+逆向转运蛋白在两种盐分变化情况下的表达变化:1)从无盐处理转移到200 mM NaCl处理;2)从200 mM NaCl培养基转移到无盐培养基。结果表明:SeNHX4的表达量非常低,在地下部几乎检测不到;SeNhaD在地上部的表达量是地下部的2倍左右,说明NhaD主要在盐角草地上部发挥作用;SeNHX1、SeNHX3和SeNHX5的表达量明显高于其他两个基因,对盐角草的耐盐机制起到更大的作用,并且SeNHX1和SeNHX5受盐分诱导表达,表达量与盐浓度呈正相关,可能在盐角草耐盐调控网络中发挥重要作用。综上,NHX基因家族和NhaD的表达量受到基质中盐分的调控作用,其表达在盐分处理或者盐分去除1~3 d后发生变化。研究结果有助于阐明盐角草NHX基因家族和NhaD对盐分的响应特点。
