scholarly journals Aspects of potassium and magnesium uptake by oats.

1974 ◽  
Vol 22 (4) ◽  
pp. 237-244
Author(s):  
A.C. Schuffelen
Keyword(s):  
Direct Relationship ◽  
Common Mechanism ◽  
Specific Mechanism ◽  
K Uptake ◽  
Uptake Mechanism ◽  
Water Culture ◽  
Mg Deficiency ◽  
Magnesium Uptake ◽  
Low K ◽  
Solution Acidity

Data from a range of experiments with oats in water culture indicated that the occurrence of Mg deficiency had only a slight direct relationship with solution acidity. It was calculated that about 3% of the total mechanism for the uptake of K and Mg consisted of a specific mechanism for Mg uptake, 30% of a specific mechanism for K uptake, and 67% of a common mechanism. It was not clear whether one or more systems were involved. At very low K concentrations the specific K uptake mechanism could also take up Na. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals ZMK1 Is Involved in K+ Uptake and Regulated by Protein Kinase ZmCIPK23 in Zea mays

2021 ◽  
Vol 12 ◽  
Author(s):  
Wu Han ◽  
Yun Ji ◽  
Wei Wu ◽  
Jin-Kui Cheng ◽  
Han-Qian Feng ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Growth And Development ◽  
Mineral Elements ◽  
Plant Roots ◽  
Plant Growth And Development ◽  
K Uptake ◽  
Uptake Mechanism ◽  
Uptake Activity ◽  
Electrophysiological Characterization ◽  
Low K

Potassium (K+) is one of essential mineral elements for plant growth and development. K+ channels, especially AKT1-like channels, play crucial roles in K+ uptake in plant roots. Maize is one of important crops; however, the K+ uptake mechanism in maize is little known. Here, we report the physiological functions of K+ channel ZMK1 in K+ uptake and homeostasis in maize. ZMK1 is a homolog of Arabidopsis AKT1 channel in maize, and mainly expressed in maize root. Yeast complementation experiments and electrophysiological characterization in Xenopus oocytes indicated that ZMK1 could mediate K+ uptake. ZMK1 rescued the low-K+-sensitive phenotype of akt1 mutant and enhanced K+ uptake in Arabidopsis. Overexpression of ZMK1 also significantly increased K+ uptake activity in maize, but led to an oversensitive phenotype. Similar to AKT1 regulation, the protein kinase ZmCIPK23 interacted with ZMK1 and phosphorylated the cytosolic region of ZMK1, activating ZMK1-mediated K+ uptake. ZmCIPK23 could also complement the low-K+-sensitive phenotype of Arabidopsis cipk23/lks1 mutant. These findings demonstrate that ZMK1 together with ZmCIPK23 plays important roles in K+ uptake and homeostasis in maize.

scholarly journals Magnesium isotope fractionation reflects plant response to magnesium deficiency in magnesium uptake and allocation: a greenhouse study with wheat

2020 ◽  
Vol 455 (1-2) ◽  
pp. 93-105
Author(s):  
Yi Wang ◽  
Bei Wu ◽  
Anne E. Berns ◽  
Ying Xing ◽  
Arnd J. Kuhn ◽  
...  
Keyword(s):  
Isotope Fractionation ◽  
Magnesium Deficiency ◽  
Growth Media ◽  
Growth Stages ◽  
Mg Deficiency ◽  
Greenhouse Study ◽  
Stable Isotope Fractionation ◽  
Magnesium Uptake ◽  
Mg Isotopes ◽  
Whole Plants

Abstract Aims Magnesium (Mg) deficiency is detrimental to plant growth. However, how plants respond to Mg deficiency via regulation of Mg uptake and allocation is yet not fully understood. In this study, we tested whether Mg isotope compositions (δ26Mg) associated with Mg mass balance of the plants could be used as an indicator to trace Mg uptake and subsequent translocation processes under sufficient and low-Mg supply conditions. We aimed at using stable isotope fractionation as a novel proxy for nutrient uptake and cycling in plants. Methods We grew wheat plants (Triticum aestivum) in a greenhouse under control (1 mM Mg) and low-Mg supply (0.05 mM Mg) conditions, respectively. The Mg concentrations and isotope compositions in roots, stems, leaves and spikes/grains at different growth stages were analyzed. Results Wheat plants were systematically enriched in heavy Mg isotopes relative to the nutrient solution regardless of Mg supply conditions. With crop growth, the δ26Mg of the whole plants, as well as each plant organ, gradually shifted towards higher values in the control. However, the δ26Mg value of the whole plants in the low-Mg supply did not vary significantly. In addition, the wheat stems and spikes showed continuous enrichment of lighter Mg isotopes in the low-Mg supply than those in the control. Conclusions As reflected from Mg isotope compositions, the Mg supply in the growth media could affect the Mg uptake and subsequent translocation processes in plants. Changes in δ26Mg indicated that wheat plants likely regulated their Mg uptake strategy by switching between active and passive pathways during their life cycle. When Mg supply was low, a more negative δ26Mg value of the spikes suggested a potentially enhanced remobilization of Mg from leaves to spikes. Our results showed that Mg stable isotopes can provide new insights into plants’ response to nutrient shortage.

scholarly journals Electrolyte Metabolism in HeLa Cells

1963 ◽  
Vol 46 (6) ◽  
pp. 1303-1315 ◽  
Author(s):  
Margaret Wickson-ginzburg ◽  
A. K. Solomon
Keyword(s):  
Transport System ◽  
Hela Cells ◽  
Generation Time ◽  
Chemical Concentration ◽  
Concentration Gradients ◽  
K Uptake ◽  
Initial Value ◽  
Electrolyte Metabolism ◽  
K Cells ◽  
Low K

Methods have been developed to study cellular Na, K, and Cl concentrations in HeLa cells. Cell [Na] and [K] are functions of the age of the culture. As the culture grows [K], expressed in mmols/liter cell H2O, rises from an initial value of 121 to a peak of 206 at about 4 days, and thereafter falls until it has almost returned to the initial value by the 9th day. [Na] falls as [K] rises, but there is no fixed relationship between the cellular concentrations of the two cations. There is, however, a correlation between generation time and cellular [K]. Measurements of net K uptake and net Na extrusion were carried out during 1 hour incubation at 37°C of low K cells. Both net K uptake and net Na extrusion took place against chemical concentration gradients, so that at least one transport system must be active; if the Cl distribution is passive both net K uptake and net Na extrusion are active. Studies with inhibitors of respiration and glycolysis lead to the conclusion that respiration is not required for these net transports, which appear to derive their energy from glycolytic sources.

Swelling, NEM, and A23187 activate Cl(-)-dependent K+ transport in high-K+ sheep red cells

1987 ◽  
Vol 252 (2) ◽  
pp. C197-C204 ◽  
Author(s):  
H. Fujise ◽  
P. K. Lauf
Keyword(s):  
Metal Ion ◽  
Red Cells ◽  
Common Mechanism ◽  
Ionophore A23187 ◽  
Sheep Red Cells ◽  
High K ◽  
Sh Group ◽  
Low K ◽  
K Transport ◽  
Significant Activation

In low K+ (LK) sheep red cells a significant fraction of the total ouabain-resistant (OR) K+ flux is inhibited when Cl- is replaced by other anions of the Hofmeister series except Br- (Cl(-)-dependent K+ flux). In contrast, high K+ (HK) sheep red cells in isosmotic media did not possess any significant OR Cl(-)-dependent K+ flux when Cl- was replaced by NO3- or I-. However, exposure to hyposmotic solutions, treatment with the sulfhydryl (SH) group reagent N-ethylmaleimide (NEM) or with the bivalent metal ion (Me2+) ionophore A23187 in absence of external Me2+ caused a significant activation of Cl(-)-dependent K+ transport as measured with Rb+ as K+ congener. There was no Cl(-)-dependent Rb+ flux in A23187-treated cells when Mn2+, Mg2+, and Ca2+ were present at 1 mM concentrations, suggesting that cellular accumulation of these Me2+ is inhibitory. Similar to LK red cells, HK red cells failed to respond to A23187 when pretreated with NEM supporting the hypothesis proposed recently (Lauf, P. K. J. Membr. Biol. 88: 1-13, 1985) of a common mechanism of Cl(-)-dependent K+ transport activation. The magnitudes of the Cl(-)-dependent Rb+ fluxes in HK cells were much smaller than those elicited by identical treatments in LK red cells, and the effect of all interventions was not due to the presence of reticulocytes known to possess Cl(-)-dependent K+ transport.(ABSTRACT TRUNCATED AT 250 WORDS)

Potassium restriction, high protein intake, and metabolic acidosis increase expression of the glutamine transporter SNAT3 (Slc38a3) in mouse kidney

2009 ◽  
Vol 297 (2) ◽  
pp. F440-F450 ◽  
Author(s):  
Stephanie M. Busque ◽  
Carsten A. Wagner
Keyword(s):  
Metabolic Acidosis ◽  
Protein Intake ◽  
Phosphoenolpyruvate Carboxykinase ◽  
High Protein ◽  
Ammonium Excretion ◽  
Uptake Mechanism ◽  
High Protein Intake ◽  
Glutamine Transporter ◽  
Potassium Restriction ◽  
Low K

Kidneys produce ammonium to buffer and excrete acids through metabolism of glutamine. Expression of the glutamine transporter Slc38a3 (SNAT3) increases in kidney during metabolic acidosis (MA), suggesting a role during ammoniagenesis. Potassium depletion and high dietary protein intake are known to elevate renal ammonium excretion. In this study, we examined SNAT3, phosphate-dependent glutaminase (PDG), and phosphoenolpyruvate carboxykinase (PEPCK) regulation during a control (0.36%) or low-K+ (0.02%) diet for 7 or 14 days or a control (20%) or high-protein (50%) diet for 7 days. MA was induced in control and low-K+ groups by addition of NH4Cl. Urinary ammonium excretion increased during MA, after 14-day K+ restriction alone, and during high protein intake. SNAT3, PDG, and PEPCK mRNA abundance were elevated during MA and after 14-day K+ restriction but not during high protein intake. SNAT3 protein abundance was enhanced during MA (both control and low K+), after 14-day low-K+ treatment alone, and during high protein intake. Seven-day dietary K+ depletion alone had no effect. Immunohistochemistry showed SNAT3 staining in earlier parts of the proximal tubule during 14-day K+ restriction with and without NH4Cl treatment and during high protein intake. In summary, SNAT3, PDG, and PEPCK mRNA expression were congruent with urinary ammonium excretion during MA. Chronic dietary K+ restriction, high protein intake, and MA enhance ammoniagenesis, an effect that may involve enhanced SNAT3 mRNA and protein expression. Our data suggest that SNAT3 plays an important role as the glutamine uptake mechanism in ammoniagenesis under these conditions.

A low K+signal is required for functional high-affinity K+uptake through HAK5 transporters

2014 ◽  
Vol 152 (3) ◽  
pp. 558-570 ◽  
Author(s):  
Francisco Rubio ◽  
Mario Fon ◽  
Reyes Ródenas ◽  
Manuel Nieves-Cordones ◽  
Fernando Alemán ◽  
...  
Keyword(s):  
K Uptake ◽  
High Affinity ◽  
Low K

scholarly journals Net Uptake of Potassium in Neurospora Exchange for sodium and hydrogen ions

1968 ◽  
Vol 52 (3) ◽  
pp. 424-443 ◽  
Author(s):  
Clifford L. Slayman ◽  
Carolyn W. Slayman
Keyword(s):  
Transport System ◽  
Potassium Uptake ◽  
Hydrogen Ions ◽  
Cell Water ◽  
K Uptake ◽  
Respiratory Inhibition ◽  
Net Uptake ◽  
Order Of Magnitude ◽  
External Site ◽  
Low K

Net uptake of potassium by low K, high Na cells of Neurospora at pH 5.8 is accompanied by net extrusion of sodium and hydrogen ions. The amount of potassium taken up by the cells is matched by the sum of sodium and hydrogen ions lost, under a variety of conditions: prolonged preincubation, partial respiratory inhibition (DNP), and lowered [K]o. All three fluxes are exponential with time and obey Michaelis kinetics as functions of [K]o. The Vmax for net potassium uptake, 22.7 mmoles/kg cell water/min, is very close to that for K/K exchange reported previously (20 mmoles/kg cell water/min). However, the apparent Km for net potassium uptake, 11.8 mM [K]o, is an order of magnitude larger than the value (1 mM) for K/K exchange. It is suggested that a single transport system handles both net K uptake and K/K exchange, but that the affinity of the external site for potassium is influenced by the species of ion being extruded.

scholarly journals The effect of potash fertilization on dry matter production of permanent pasture throughout the season.

1958 ◽  
Vol 6 (2) ◽  
pp. 124-130
Author(s):  
P. De Vries ◽  
C.T. De Wit
Keyword(s):  
Sandy Soil ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Effect Of Temperature ◽  
K Uptake ◽  
Permanent Pasture ◽  
Matter Production ◽  
Low K ◽  
K Response

On sandy soil of low K availability, permanent pasture cut 5 times during the year received up to 200 kg/ha K2O as 40% KC1 before or after one of the cuts. The effect of K fertilizing in autumn depended largely on K withdrawal with previous cuts. K uptake was not determined by growth. Except for the first cut K uptake was greater than that needed for reasonable growth. No effect of temperature on K response was found. The best treatment was 200 kg/ha K2O applied in spring. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Potassium Uptake, Physiological and Molecular Responses in Different Winter Wheat Cultivars under Deficit Irrigation and Potassium Levels

2021 ◽  
Vol 25 (05) ◽  
pp. 937-944
Author(s):  
Xinyang Bai
Keyword(s):  
Winter Wheat ◽  
Biomass Production ◽  
Deficit Irrigation ◽  
Agronomic Traits ◽  
Photosynthetic Parameters ◽  
Wheat Cultivars ◽  
K Uptake ◽  
Winter Wheat Cultivars ◽  
Use Efficiency ◽  
Low K

Improving potassium (K) use efficiency (KUE) is beneficial for the sustainable production of cereal crops. In this study, the effects of K input level on its uptake and agronomic trait of the winter wheat under deficit irrigation were investigated in K deprivation responses, using two cultivars contrasting (low-K tolerant cultivar Kenong 9204 and K deprivation sensitive one Jimai 120). Under sufficient-K treatment (K180, SK), the two cultivars showed similar K contents, and K accumulation, biomass, photosynthetic parameters in upper expanded leaves, including yield components. Under deficient-K (K60, DK) condition, both cultivars showed varied behaviors of the K-associated traits, physiological parameters, growth and agronomic traits; however, better response was observed in Kenong 9204 than Jimai 120. These results suggested the essential roles of low-K tolerant cultivars under the K-saving management together with deficit irrigation. Two genes of the potassium transporter (HAK) family, TaHAK3 and TaHAK5, showed expression of significantly upregulated upon K deprivation, with much more transcripts shown in the K-deprived Kenong 9204 plants than Jimai 120 ones. Transgene analysis on the HAK genes validated their positive roles in modulating the K accumulation and biomass production of plants under low-K condition. These results indicated that distinct HAK family genes are transcriptionally regulated underlying K deprivation signaling and contribute to plant K uptake and biomass production under low-K conditions. This study suggested the drastically genetic variation on K uptake and biomass production across winter wheat cultivars treated by K- and water-saving conditions, associated with transcription efficiency of the distinct HAK genes which modulate K uptake, growth and development of plants. © 2021 Friends Science Publishers

Dietary Pyridoxine Loadings Affect Incidence of “Spontaneous” Seizures among Magnesium-Deprived Mongolian Gerbils (Meriones Unguiculatus)

1988 ◽  
Vol 66 (1) ◽  
pp. 327-337 ◽  
Author(s):  
Arthur E. Harriman
Keyword(s):  
Open Field ◽  
Meriones Unguiculatus ◽  
Common Mechanism ◽  
Mongolian Gerbils ◽  
Mg Deficiency ◽  
Spontaneous Seizures

The “spontaneous” tetanic attacks in magnesium (Mg) deficiency resemble those occurring in pyridoxine (Pyr) deficiency. A common mechanism may underlie both seizure patterns. Nine groups ( n = 10) of male Mongolian gerbils that were Mg-deprived, Pyr-deprived, or both were used to explore this possibility. The animals were tested for spontaneous seizing in an open field at four-day intervals over 40 days. By the end of the period, 70% of the gerbils that were both Mg- and Pyr-deprived had seized, and 90% had died. One fatality, but no seizures, occurred among Pyr-deprived groups given 500 to 2,000 ppm Mg in the food. No seizures occurred among the Mg-deprived groups fed 20 to 100 ppm Pyr, though several animals given 20 ppm Pyr died. Deaths and seizures occurred within Mg-deprived groups fed more than 100 ppm Pyr. A possible role of Pyr in Mg metabolism is discussed.

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