Abstract
Vesicles enriched in right‐side‐out plasma membranes were isolated from corn roots by a modified two‐phase partition method. Using reduced nicotinamide adenine dinucleotide as electron donor, isolated vesicles were capable of reducing both ferricyanide and oxygen. At pH 6.0, the presence of Al inhibited both reduction processes to a similar extent. This result indicates that these two reduction processes share at least one common step that is sensitive to Al. Inhibition was not associated with a change in the structure of the membrane domain, as revealed by fluorescence polarization of membrane incorporated probes. These results are the first indications that the electron transfer processes of plasma membranes are sensitive to the presence of Al.