Regulation of K+ transport and cell electropotential in segments of pea epicotyl.

Abstract

The time course of K' ~uptake. fresh weight increase. and the pH changes of the external solution have befollowed during the incubation of epicotyl segments from etiolated pea ( Pisum sativum cv. Alaska) with 2,4-Dichlorophenoxyacetic acid (2,4-D ). The influence of varying concentrations, of the temperatures. and the addition of an energy source (0.01 M sucrose) have been explored.Treatment with 0.001mM 2 ,4-D produced An inhibition of K+ uptake, a depolarization of the cell PD, and ;an increase in the fresh weight. Higher concentrations. of 2.4-D or low concentrations at highertemperatures promoted the extrusion of K+ from the tissue.