Potassium and Phosphorus

Abstract

Aeration of submersed corn roots doubles the subsequent uptake rate of ions. This augmentation is accompanied by hyperpolari‐zation of membrane potential, depends upon aeration and protein synthesis, and is associated with changes in membrane proteins. Potassium uptake (⁸⁶Rb) by excised and intact roots before and after augmentation was measured, and potassium losses by roots at different temperatures or in the presence of dinitrophenol was followed.

Relevant effluxes of potassium follow excision and/or submersion or roots, and a metabolism‐dependent process must be carried out by roots in order to recover the control of membrane permeability. Moreover, we show that corn hybrids of different maturity classes differ not only for initial ion uptake rates but also for the ability to recover control of membrane permeability.

Key words:

• Zea mays L.
• potassium flux
• augmentation