Selectivity of Alkali Cation Influx Across the Plasma Membrane of Oat Roots

Abstract

Influx of alkali cations (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺) across plasma membranes of cells of excised roots of Avena sativa cv. Goodfield was selective, but different, in the absence and in the presence of 1 mm CaSO₄. Ca²⁺ reduced the influx rates of all of the alkali cations—especially Na⁺ and Li⁺. Transport selectivity changed as the external concentrations of the alkali cations increased.