Transmembrane electron transport in sealed and NAD(P)H‐loaded right‐side‐out plasma membrane vesicles isolated from maize (Zea mays L.) roots

摘要: Electron transport across plasma membranes has been observed in vivo several plant species and tissues after the application of ferricyanide (hexacyanoferrate III, HCF III). In present work, a transmembrane electron flow was demonstrated sealed NAD(P)H-loaded right-side-out (apoplastic-side-out) membrane vesicles isolated from maize (Zea mays L.) roots. III reduced at rate up to 126 nmol min(-1) mg(-1) protein by NADPH-loaded vesicles, while reduction rates with NADH-loaded were several-fold lower. Coincident NAD(P)H oxidation inside vesicles. The dependence on K+ indicated an electrogenic flow. Application 100 microM calcium decreased 66%, pre-incubation 200 warfarin or diphenylene iodonium inhibited only weakly. Fe(3+)-EDTA not significantly whereas XTT 765 pmol protein. results suggested major function for NADPH discussed conjunction experiments.