Effects of some amino acid analogues on the uptake and transport of K+ and Ca2+ in wheat and mung bean seedlings. II. Uptake and translocation in whole seedling plants

The effects of some amino acid analogues (o-, m- and p-fluorophenylalanine and azetidine-2-carboxylic acid) on uptake of 42K and 45Ca into the roots and transport to the shoots of whole wheat and mung bean seedlings were measured. The effect of each analogue on either K+ or Ca2+ movement could be placed into one of four categories: (1) No effect on either ion uptake or transport; (2) No effect on ion uptake, but a reduction in transport; (3) Similar reductions in ion uptake and transport; (4) A relatively greater reduction in ion transport than in uptake. At least two independent sites of protein involvement in ion movement were required to account for all four types of analogue effect observed; one site of protein involvement was probably at the plasmalemma of root cortex cells and the second site, involving a protein that turned over more quickly, was within the stele. Some evidence was found that Ca2+ transport is a passive process. Light did not stimulate uptake.