Soil salinity causes the negative effects on the growth and yield of crops. In this study, two sweet potato （Ipomoea batatas L.） cultivars, Xushu 28 （X-28） and Okinawa 100 （O-100）, were examined under 50 and 100...Soil salinity causes the negative effects on the growth and yield of crops. In this study, two sweet potato （Ipomoea batatas L.） cultivars, Xushu 28 （X-28） and Okinawa 100 （O-100）, were examined under 50 and 100 mmol L-1 NaCI stress. X-28 cultivar is relatively high salt tolerant than O-100 cultivar. Interestingly, real-time quantitative polymerase chain reaction （RT-qPCR） results indicated that sweet potato high-affinity K^＋ transporter 1 （IbHKT1） gene expression was highly induced by 50 and 100 mmol L-1 NaCI stress in the stems of X-28 cultivar than in those of O-100 cultivar, but only slightly induced by these stresses in the leaves and fibrous roots in both cultivars. To characterize the function of IbHKT1 transporter, we performed ion-flux analysis in tobacco transient system and yeast complementation. Tobacco transient assay showed that IbHKT1 could uptake sodium （Na^＋）. Yeast complementation assay showed that IbHKT1 could take up K^＋ in 50 mmol L^-1 K^＋ medium without the presence of NaCI. Moreover, Na^＋ uptake significantly increased in yeast overexpressing IbHKTI. These results showed that IbHKT1 transporter could have K^＋-Na^＋ symport function in yeast. Therefore, the modes of action of IbHKT1 in transgenic yeast could differ from the mode of action of the other HKT1 transporters in class I. Potentially, IbHKT1 could be used to improve the salt tolerance nature in sweet potato.展开更多
The title complex [Na（H2MIA-）（H2O）]（1,H3MIA = 2-methyl-1H-imidazole-4,5-dicarboxylic acid） has been synthesized by hydrothermal synthesis and structurally characterized by X-ray crystallography.Compound 1 crysta...The title complex [Na（H2MIA-）（H2O）]（1,H3MIA = 2-methyl-1H-imidazole-4,5-dicarboxylic acid） has been synthesized by hydrothermal synthesis and structurally characterized by X-ray crystallography.Compound 1 crystallizes in orthorhombic,space group ibam with a = 14.4737（19）,b = 17.553（2）,c = 6.5285（9）,V = 1658.6（4） 3,C6H7N2NaO5,Mr = 210.12,Z = 8,Dc = 1.675 g/cm3,F（000） = 864,μ = 0.188 mm-1,λ（MoKα） = 0.071073 ,R = 0.0383 and wR = 0.0987 for 1046 observed reflections（I 2σ（I））.In the structure of 1,each coordination water coordinates with two Na（I） ions at the same time and links the neighboring Na（I） ions to form a one-dimensional Na（I）-water chain.Each H2MIA-ligand links the neighboring Na（I） of Na（I）-water chain to form a novel two-dimensional supramolecular network.The 2-D network is stabilized by O-H…N hydrogen bonds and π-π interaction.The 2D network is further linked via O-H…O hydrogen bonds to yield a three-dimensional framework.展开更多
Conditions in rat and turtle small intestine tissue where glucose and glycine transport is inhibited while glucose-induced Na+ transport is preserved are described. The generally accepted model for the Na+-dependent t...Conditions in rat and turtle small intestine tissue where glucose and glycine transport is inhibited while glucose-induced Na+ transport is preserved are described. The generally accepted model for the Na+-dependent transporter (а single channel for the Na+ and nutrient) does not account for the data obtained from the analysis of the interaction between the transport of glucose, glycine, and Na+ at different temperatures and the effect of inhibitors оn these рroсеssеs. The phenomenon of temperature uncoupling of Na+ and nutrient transport саn best bе described bу а two-pathway model with а gate mechanism. According to this model, the Na+-dependent transporter has at least two pathways: оnе for Na+ and another for nutrients. The model рrovidеs for the passage of Na+ in both directions along а channel opened bу glucose. Experiments are carried out using the addition of glucose and glycine on backgrounds of glycine and glucose, respectively. It has been hypothesized that when all three transporters (for Na+, glucose and glycine) are unite in a single structure, then there should be “competitive relations” between short-circuit current changes on glycine and glucose for sodium ions passing through its transporter.展开更多
Salinity is a global challenge to agricultural production. Understanding Na^+ sensing and transport in plants under salt stress will be of benefit for breeding robustly salt-tolerant crop species. In this review, firs...Salinity is a global challenge to agricultural production. Understanding Na^+ sensing and transport in plants under salt stress will be of benefit for breeding robustly salt-tolerant crop species. In this review, first, possible salt stress sensor candidates and the root meristem zone as a tissue harboring salt stress-sensing components are proposed. Then,the importance of Na^+ exclusion and vacuolar Na^+ sequestration in plant overall salt tolerance is highlighted. Other Na^+ regulation processes, including xylem Na^+ loading and unloading, phloem Na^+ recirculation, and Na^+ secretion, are discussed and summarized.Along with a summary of Na^+ transporters and channels, the molecular regulation of Na^+ transporters and channels in response to salt stress is discussed. Finally, some largely neglected issues in plant salt stress tolerance, including Na^+ concentration in cytosol and the role of Na^+ as a nutrient, are reviewed and discussed.展开更多
The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity,plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that,plasma osmolality was sim...The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity,plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that,plasma osmolality was similar among flounder adapted to different Na+/K+ ratios of saline groundwaters (P>0.05),while the growth,gill Na+,K+-ATPase and HCO3--ATPase activities were affected by Na+/K+ ratio significantly (P<0.05). The gill Na+,K+-ATPase activity reached its maximum on day 3,then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na+,K+-ATPase activity were detected on day 3 for all Na+/K+ ratios of saline groundwaters,then the enzyme activities descended,and on day 9 the enzyme activi-ties achieved steady state,and the gill HCO3--ATPase activity increased rapidly and achieved steady state after one day. During steady state,the gill Na+,K+-ATPase and HCO3--ATPase activity of Na+/K+ ratios 20 and 40 treatments were significantly higher than those in the control group (Na+/K+ ratio 27.5),while there were no significant differences between the Na+/K+ ratio 30 treatment and the control group; the gill Na+,K+-ATPase activity of Na+/K+ ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment,but there were no significant differences of gill HCO3--ATPase activity among these treatments. At the end of the 15-day experiment,the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na+/K+ ratio 30 treatment had the highest values (33.7% and 1.94 respectively),which were significantly higher than those under Na+/K+ ratios 20 and 40 treatments. There-fore,for the saline groundwater used in this experiment,it is suggested that the Na+/K+ ratio be adjusted to approximately 30,i.e.,as close to that of natural seawater as possible in the culture of flounder.展开更多
Renal tubules regulate blood pressure and humoral homeostasis.Mediators that play a significant role in regulating the transport of solutes and water include angiotensin Ⅱ(AngⅡ) and nitric oxide(NO).AngⅡ can signif...Renal tubules regulate blood pressure and humoral homeostasis.Mediators that play a significant role in regulating the transport of solutes and water include angiotensin Ⅱ(AngⅡ) and nitric oxide(NO).AngⅡ can significantly raise blood pressure via effects on the heart,vasculature,and renal tubules.AngⅡ generally stimulates sodium reabsorption by triggering sodium and fluid retention in almost all segments of renal tubules.Stimulation of renal proximal tubule(PT) transport is thought to be essential for AngⅡ-mediated hypertension.However,AngⅡ has a biphasic effect on in vitro PT transport in mice,rats,and rabbits:stimulation at low concentrations and inhibition at high concentrations.On the other hand,NO is generally thought to inhibit renal tubular transport.In PTs,NO seems to be involved in the inhibitory effect of AngⅡ.A recent study reports a surprising finding:AngⅡ has a monophasic stimulatory effect on human PT transport.Detailed analysis of signalling mechanisms indicates that in contrast to other species,the human NO/guanosine3',5'-cyclic monophosphate/extracellular signal-regulated kinase pathway seems to mediate this effect of AngⅡ on PT transport.In this review we will discuss recent progress in understanding the effects of AngⅡ and NO on renal tubular transport.展开更多
基金supported by the China Agriculture Research System (CARS-10,Sweetpotato)the Agricultural Science and Technology Innovation Program of Jiangsu Province,China (CX(13)2032)the China-Korea Young Scientist Exchange Program
文摘Soil salinity causes the negative effects on the growth and yield of crops. In this study, two sweet potato （Ipomoea batatas L.） cultivars, Xushu 28 （X-28） and Okinawa 100 （O-100）, were examined under 50 and 100 mmol L-1 NaCI stress. X-28 cultivar is relatively high salt tolerant than O-100 cultivar. Interestingly, real-time quantitative polymerase chain reaction （RT-qPCR） results indicated that sweet potato high-affinity K^＋ transporter 1 （IbHKT1） gene expression was highly induced by 50 and 100 mmol L-1 NaCI stress in the stems of X-28 cultivar than in those of O-100 cultivar, but only slightly induced by these stresses in the leaves and fibrous roots in both cultivars. To characterize the function of IbHKT1 transporter, we performed ion-flux analysis in tobacco transient system and yeast complementation. Tobacco transient assay showed that IbHKT1 could uptake sodium （Na^＋）. Yeast complementation assay showed that IbHKT1 could take up K^＋ in 50 mmol L^-1 K^＋ medium without the presence of NaCI. Moreover, Na^＋ uptake significantly increased in yeast overexpressing IbHKTI. These results showed that IbHKT1 transporter could have K^＋-Na^＋ symport function in yeast. Therefore, the modes of action of IbHKT1 in transgenic yeast could differ from the mode of action of the other HKT1 transporters in class I. Potentially, IbHKT1 could be used to improve the salt tolerance nature in sweet potato.
基金supported by the Research Foundation of Educational Department of Jiangxi Province (GJJ10421)the Natural Science Foundation of Jiangxi Agricultural University (09003321)
文摘The title complex [Na（H2MIA-）（H2O）]（1,H3MIA = 2-methyl-1H-imidazole-4,5-dicarboxylic acid） has been synthesized by hydrothermal synthesis and structurally characterized by X-ray crystallography.Compound 1 crystallizes in orthorhombic,space group ibam with a = 14.4737（19）,b = 17.553（2）,c = 6.5285（9）,V = 1658.6（4） 3,C6H7N2NaO5,Mr = 210.12,Z = 8,Dc = 1.675 g/cm3,F（000） = 864,μ = 0.188 mm-1,λ（MoKα） = 0.071073 ,R = 0.0383 and wR = 0.0987 for 1046 observed reflections（I 2σ（I））.In the structure of 1,each coordination water coordinates with two Na（I） ions at the same time and links the neighboring Na（I） ions to form a one-dimensional Na（I）-water chain.Each H2MIA-ligand links the neighboring Na（I） of Na（I）-water chain to form a novel two-dimensional supramolecular network.The 2-D network is stabilized by O-H…N hydrogen bonds and π-π interaction.The 2D network is further linked via O-H…O hydrogen bonds to yield a three-dimensional framework.
文摘Conditions in rat and turtle small intestine tissue where glucose and glycine transport is inhibited while glucose-induced Na+ transport is preserved are described. The generally accepted model for the Na+-dependent transporter (а single channel for the Na+ and nutrient) does not account for the data obtained from the analysis of the interaction between the transport of glucose, glycine, and Na+ at different temperatures and the effect of inhibitors оn these рroсеssеs. The phenomenon of temperature uncoupling of Na+ and nutrient transport саn best bе described bу а two-pathway model with а gate mechanism. According to this model, the Na+-dependent transporter has at least two pathways: оnе for Na+ and another for nutrients. The model рrovidеs for the passage of Na+ in both directions along а channel opened bу glucose. Experiments are carried out using the addition of glucose and glycine on backgrounds of glycine and glucose, respectively. It has been hypothesized that when all three transporters (for Na+, glucose and glycine) are unite in a single structure, then there should be “competitive relations” between short-circuit current changes on glycine and glucose for sodium ions passing through its transporter.
基金supported by a Ph.D. scholarship provided by University of Tasmania (185466S9A),Australiathe Open Fund of State Key Laboratory of Tea Plant Biology Utilization at Anhui Agricultural University (SKLTOF20170112)
文摘Salinity is a global challenge to agricultural production. Understanding Na^+ sensing and transport in plants under salt stress will be of benefit for breeding robustly salt-tolerant crop species. In this review, first, possible salt stress sensor candidates and the root meristem zone as a tissue harboring salt stress-sensing components are proposed. Then,the importance of Na^+ exclusion and vacuolar Na^+ sequestration in plant overall salt tolerance is highlighted. Other Na^+ regulation processes, including xylem Na^+ loading and unloading, phloem Na^+ recirculation, and Na^+ secretion, are discussed and summarized.Along with a summary of Na^+ transporters and channels, the molecular regulation of Na^+ transporters and channels in response to salt stress is discussed. Finally, some largely neglected issues in plant salt stress tolerance, including Na^+ concentration in cytosol and the role of Na^+ as a nutrient, are reviewed and discussed.
基金the Agricultural Science and Technology Achievement Transfer Project of Tianjin City of China (Transfer of the Large-scale health culture technology of fish and shrimp)the Science and Technology Program of Shengli Oil Field Administration Bureau (The exploring study on the culture technology of fish and shrimp using saline groundwaters)
文摘The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity,plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that,plasma osmolality was similar among flounder adapted to different Na+/K+ ratios of saline groundwaters (P>0.05),while the growth,gill Na+,K+-ATPase and HCO3--ATPase activities were affected by Na+/K+ ratio significantly (P<0.05). The gill Na+,K+-ATPase activity reached its maximum on day 3,then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na+,K+-ATPase activity were detected on day 3 for all Na+/K+ ratios of saline groundwaters,then the enzyme activities descended,and on day 9 the enzyme activi-ties achieved steady state,and the gill HCO3--ATPase activity increased rapidly and achieved steady state after one day. During steady state,the gill Na+,K+-ATPase and HCO3--ATPase activity of Na+/K+ ratios 20 and 40 treatments were significantly higher than those in the control group (Na+/K+ ratio 27.5),while there were no significant differences between the Na+/K+ ratio 30 treatment and the control group; the gill Na+,K+-ATPase activity of Na+/K+ ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment,but there were no significant differences of gill HCO3--ATPase activity among these treatments. At the end of the 15-day experiment,the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na+/K+ ratio 30 treatment had the highest values (33.7% and 1.94 respectively),which were significantly higher than those under Na+/K+ ratios 20 and 40 treatments. There-fore,for the saline groundwater used in this experiment,it is suggested that the Na+/K+ ratio be adjusted to approximately 30,i.e.,as close to that of natural seawater as possible in the culture of flounder.
文摘Renal tubules regulate blood pressure and humoral homeostasis.Mediators that play a significant role in regulating the transport of solutes and water include angiotensin Ⅱ(AngⅡ) and nitric oxide(NO).AngⅡ can significantly raise blood pressure via effects on the heart,vasculature,and renal tubules.AngⅡ generally stimulates sodium reabsorption by triggering sodium and fluid retention in almost all segments of renal tubules.Stimulation of renal proximal tubule(PT) transport is thought to be essential for AngⅡ-mediated hypertension.However,AngⅡ has a biphasic effect on in vitro PT transport in mice,rats,and rabbits:stimulation at low concentrations and inhibition at high concentrations.On the other hand,NO is generally thought to inhibit renal tubular transport.In PTs,NO seems to be involved in the inhibitory effect of AngⅡ.A recent study reports a surprising finding:AngⅡ has a monophasic stimulatory effect on human PT transport.Detailed analysis of signalling mechanisms indicates that in contrast to other species,the human NO/guanosine3',5'-cyclic monophosphate/extracellular signal-regulated kinase pathway seems to mediate this effect of AngⅡ on PT transport.In this review we will discuss recent progress in understanding the effects of AngⅡ and NO on renal tubular transport.
