Selectivity and ion transport in excised bean hypocotyls

Abstract Ion transport and ion selectivity in bean hypocotyl slices were investigated. The transport mechanism is practically independent of temperature and in short term experiments appears to be non‐metabolic. Selectivity may be attributed either to specific adsorption sites or to the properties of the diffusion barrier. The fact that with a physical transport mechanism selectivity is observed only under physiological temperature conditions hints that a flexible barrier (plasmalemma?) rather than fixed adsorption sites should be regarded as governing the process.