The effect of CCCP on ion fluxes in the stele and cortex of maize roots

摘要

The accumulation of86Rb labelled potassium by isolated stelar and cortical tissues from 7-day-old roots ofZea mayshas been compared with the levels accumulated by these tissues in the intact root. Cortical tissues have similar uptake eapacities in these two conditions whereas stelar tissues only exhibit an uptake capacity in the intact root system. The uncoupler carbonylcyanidem-chlorophenylhydrazone caused a considerable decrease in the uptake of potassium by these tissues. In the intact root system it prevented ions from the bathing medium reaching the stelar tissues. The efflux pattern from preloaded isolated stelar and cortical tissues was considerably altered by the inhibitor, a promotion of the efflux occurring in both of these tissues.