KINETICS OF ABSORPTION OF K, RB AND CS FROM SOLUTION CULTURE BY INTACT PLANT-ROOTS

The experiments reported here were designed to examine the influx kinetics of K, Rb and Cs into the intact plant root systems. Roots of intact corn, onion and wheat plants showed no kinetic discrimination in absorption of K and Rb so that K and Rb are suitable cations to use for studies of the mechanism of their absorption by plant roots growing in soil systems. Absorption of Cs by corn roots was slower in relation to K absorption than would be the case if both were taken up without discrimination. There was a linear relation between K/Cs uptake and K/Cs concentration in the solution indicating that K was absorbed approximately twice as rapidly as Cs. The K-Cs pair of ions would not be suitable for studies of ion uptake mechanisms. © 1979, Taylor & Francis Group, LLC. All rights reserved.