High-affinity potassium uptake in plants.

AtKUP1: an Arabidopsis gene encoding high-affinity potassium transport activity.

Because plants grow under many different types of soil and environmental conditions, we investigated the hypothesis that multiple pathways for K+ uptake exist in plants. We have identified a new family of potassium transporters from Arabidopsis by searching for homologous sequences among the expressed sequence tags of the GenBank database. The deduced amino acid sequences of AtKUP (for Arabidop...

High-Affinity Potassium Uptake Transporter from Higher Plants

'And then there were three': highly efficient uptake of potassium by foliar trichomes of epiphytic bromeliads.

BACKGROUND AND AIMS Vascular epiphytes have to acquire nutrients from atmospheric wash out, stem-flow, canopy soils and trapped litter. Physiological studies on the adaptations to nutrient acquisition and plant utilization of nutrients have focused on phosphorus and nitrogen; potassium, as a third highly abundant nutrient element, has received minor attention. In the present study, potassium up...

High-affinity sodium uptake in land plants.

High-affinity Na(+) uptake in plants and its mediation by HKT transporters have been studied in very few species. This study expands the knowledge of high-affinity Na(+) uptake in land plants for both uptake characteristics and involvement of HKT transporters. In non-flowering plants, we analyzed the Na(+) content of wild mosses, carried out experiments on K(+) and Na(+) uptake in the micromola...

High-affinity potassium and sodium transport systems in plants.

All living cells have an absolute requirement for K+, which must be taken up from the external medium. In contrast to marine organisms, which live in a medium with an inexhaustible supply of K+, terrestrial life evolved in oligotrophic environments where the low supply of K+ limited the growth of colonizing plants. In these limiting conditions Na+ could substitute for K+ in some cellular functi...

Mechanism of high-affinity potassium uptake in roots of Arabidopsis thaliana.

Potassium is a major nutrient in higher plants, where it plays a role in turgor regulation, charge balance, leaf movement, and protein synthesis. Terrestrial plants are able to sustain growth at micromolar external K+ concentrations, at which K+ uptake across the plasma membrane of root cells must be energized despite the presence of a highly negative membrane potential. However, the mechanism ...