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Characterization of a proton translocating ATPase and sucrose uptake in a tonoplast‐enriched vesicle fraction from sugarcane
Author(s) -
Williams Lorraine,
Thom Margaret,
Maretzki Andrew
Publication year - 1990
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1990.tb04392.x
Subject(s) - vesicle , sucrose , vacuole , proton transport , biochemistry , atpase , vanadate , electrochemical gradient , population , protoplast , biology , chemistry , enzyme , membrane , cytoplasm , demography , sociology
A sucrose gradient fraction was used to characterize the tonoplast ATPase from storage tissue of the sugarcane plant ( Saccharum sp. var. H57–5175). Marker enzyme analyses and characterization of low‐density vesicles isolated on a sucrose gradient were consistent with a highly enriched tonoplast fraction. ATPase and proton transport activities were both substantially inhibited by nitrate (80%), but very little by vanadate (10%), indicating a high titer of tonoplast compared to plasma‐membrane vesicles in the fraction. Sensitivity toward other inhibitors, as well as ion effects, correlated closely among ATPase and proton translocation activities. Although the vesicles in this fraction showed good proton translocating activity there was no indication that ATP stimulated sucrose uptake in this tonoplast population.