Sulfur dioxide inhibits the sucrose carrier of the plant plasma membrane

• Published in: Biochimica et biophysica acta Vol. 1105; no. 2; pp. 230 - 236
• Main Authors: Maurousett, L, Lemoine, R, Gallet, O, Delrot, S, Bonnemain, J.L
• Format: Journal Article
• Language: English
• Published: Netherlands 13.04.1992
• Subjects: Carrier Proteins - antagonists & inhibitors; Carrier Proteins - metabolism; Cell Membrane - drug effects; Cell Membrane - metabolism; Fabaceae - metabolism; Hydrogen-Ion Concentration; inhibition; Kinetics; leaves; nutrient transport; Osmolar Concentration; Plants, Medicinal; plasma membrane; Proton-Translocating ATPases - drug effects; Proton-Translocating ATPases - metabolism; sucrose; Sucrose - metabolism; sulfites; Sulfites - pharmacology; sulfur dioxide; Sulfur Dioxide - pharmacology; Vicia faba
• ISSN: 0006-3002; 1878-2434
• DOI: 10.1016/0005-2736(92)90199-V

Plasma membrane vesicles were prepared by phase partition from a microsomal fraction of broad bean (Vicia faba L.) leaf. In order to study the effects of sodium sulfite on active uptake of sucrose, the vesicles were artificially energized by a transmembrane pH gradient (delta pH) and/or a transmembrane electrical gradient (delta psi). At 1 mM, sulfite strongly inhibited sucrose uptake but did not affect the two components of the proton motive force, delta pH (measured by dimethyloxazolidine dione) and delta psi (measured by tetraphenylphosphonium). Moreover, sulfite did not inhibit the proton-pumping ATPase of the plasma membrane vesicles. These data demonstrate that sulfite may inhibit transport of photoassimilates in plant by a direct inhibition of the sucrose carrier of the plasma membrane.