The Selective Uptake of Alkali Cations by Red Beet Root Tissue

Abstract

The selective uptake of alkali cations by red beet root tissue from solutions of chlorides has been investigated. It is shown that when disks are transferred from distilled water to a solution of salts, there is a rapid initial uptake of cations which is neither particularly selective, nor directly related to metabolism. On the other hand, the prolonged active accumulation of cations exhibits strong selectivity, Na being preferred to other ions. Evidence is presented to show that the alkali cations compete with one another for the same absorption mechanism. In this respect the material apparently differs from that investigated by Epstein and Hagen, in which the operation of distinct mechanisms for some of these ions was visualized. The validity of Epstein and Hagen's conclusion is discussed in relation to the results presented here.