CARRIER-MEDIATED CATION TRANSPORT IN BARLEY ROOTS: KINETIC EVIDENCE FOR A SPECTRUM OF ACTIVE SITES
- 1 June 1965
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 53 (6) , 1320-1324
- https://doi.org/10.1073/pnas.53.6.1320
Abstract
Two transport mechanisms are implicated in the absorption of alkali cations by barley roots. In contrast to mechanism 1, mechanism 2 only becomes operative at concentrations of about 1 m[image] and higher. Unlike mechanism 1, mechanism 2 is not highly selective for K vis-a-vis Na but transports both ions. The isotherm depicting the rate of absorption of K or Na ions as a function of their external concentrations, over the range 1-50 m[image], shows several inflections which are interpreted as evidence that mechanism 2 processes a spectrum of carrier sites with different affinities for a given cation.This publication has 4 references indexed in Scilit:
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- RESOLUTION OF DUAL MECHANISMS OF POTASSIUM ABSORPTION BY BARLEY ROOTSProceedings of the National Academy of Sciences, 1963
- SELECTIVE ABSORPTION OF CATIONS BY HIGHER PLANTSPlant Physiology, 1941
- THE INFLUENCE OF ONE ION ON THE ACCUMULATION OF ANOTHER BY PLANT CELLS WITH SPECIAL REFERENCE TO EXPERIMENTS WITH NITELLAPlant Physiology, 1928