Considerations in measuring Potassium efflux from plant cells using 87 Rb magnetic resonance

Abstract

In order to stay metabolically active, plant cells must transport Potassium ions across their plasmalemma. Ion transport is subject to many complex metabolic regulatory processes. Information on Potassium metabolism can be obtained with 87 Rb NMR spectroscopy, using Rubidium as a congener for Potassium. However, due to the presence of the vacuole, another non-metabolic mechanism for ion flux regulation exists. Using simple biophysical arguments, it is shown that an increase in vacuole size, without a change in total cell volume, could initiate a change in Potassium efflux. This change in efflux can be significant, especially for large vacuoles.

• Nmr Vacuole Cytoplasm Surface Volume Ratio Ion Transport