עמוד 1 מ 107 תוצאות
The control of potassium (K+) acquisition is a critical requirement for plant growth. Although HAK1 (high affinity K+ 1) transporters provide a pathway for K+ acquisition, the effect exerted by the ionic environment on their contribution to K+ capture remains essentially unknown. Here, the influence
To verify the possible involvement of lipids and several other compounds including hydrogen peroxide (H(2)O(2)) and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) in the response of Hordeum vulgare to early potassium deprivation, plants were grown in hydroponic conditions for 30d with a modified
The mechanism by which aluminum interferes with ion influx is not known. In this study, the effects of aluminum on the influx of the cations calcium, potassium, and ammonium and the anions nitrate and phosphate were measured in an aluminum-sensitive cultivar of barley (Hordeum vulgare L.). Aluminum
Asparaginase (EC 3.5.1.1) was isolated from the developing seed of Pisum sativum. The enzyme is dependent upon the presence of K(+) for activity, although Na(+) and Rb(+) may substitute to a lesser extent. Maximum activity was obtained at K(+) concentrations above 20 millimolar. Potassium ions
The role of potassium (K(+)) transporters in high- and low-affinity K(+) uptake was examined in roots of intact barley (Hordeum vulgare) and Arabidopsis (Arabidopsis thaliana) plants by use of (42)K radiotracing, electrophysiology, pharmacology, and mutant analysis. Comparisons were made between
Understanding the interactions between mineral nutrition and disease is essential for crop management. Our previous studies with Arabidopsis thaliana demonstrated that potassium (K) deprivation induced the biosynthesis of jasmonic acid (JA) and increased the plant's resistance to herbivorous
The involvement of potassium (K(+))-selective, Shaker-type channels, particularly AKT1, in primary K(+) acquisition in roots of higher plants has long been of interest, particularly in the context of low-affinity K(+) uptake, at high K(+) concentrations, as well as uptake from low-K(+) media under
Use of drilling waste generated from the oil and gas industry for land reclamation has potential to be a practical and economical means to improve soil fertility and to decrease landfills. A four month greenhouse experiment with common barley (Hordeum vulgare L.) on three different textured soils
The extent to which uptake and transport of either phosphate, potassium or chloride are controlled by the concentration of these ions within the root, perhaps through an allosteric mechanism, was investigated with young barley plants in nutrient solution culture. Plants were grown with their roots
In laboratory tests, treatment of the first leaves of barley (Hordeum vulgare L cv Golden Promise) with potassium phosphate led to significant reduction in infection of the second leaves with the powdery mildew fungus Blumeria graminis f sp hordei Marchal, with a 25 mM treatment giving 89% reduction
A potassium-specific tonoplast channel was identified by reconstitution of tonoplast polypeptides into planar lipid bilayer membranes. Highly purified tonoplast membranes were solubilized in Triton X-100-containing buffer and fractionated by size-exclusion chromatography. The protein fractions were
The interactive effects of salinity and potassium deficiency on the growth, mineral elements and photosynthetic performance were investigated in wild (Hordeum maritimum L.) and cultivated barley (Hordeum vulgare L. var. Manel). At 28 d of growth, plants were treated with 3 mM K and 0 mM NaCl (3-0);
Potassium (K(+) ) flux into plant cells is a well-characterized ion transport phenomenon. By contrast, little is known about the mechanisms and regulation of K(+) flux from the cell. Here, we present a radioisotopic analysis of K(+) fluxes from roots of intact barley (Hordeum vulgare), in the
From measurements of the rates of depletion of labelled ions from solution in the low concentration range, we described the phosphate and potassium uptake characteristics of the roots of intact barley plants in terms of the kinetic parameters, K m and I max (the maximum rate of uptake). In
The ability of a quadrupole-based ICP-MS with an octopole collision cell to obtain precise and accurate measurements of isotope ratios of magnesium, calcium and potassium was evaluated. Hydrogen and helium were used as collision/reaction gases for ICP-MS isotope ratio measurements of calcium and