Localization of ATPase Activity on the Plasmalemma of Scutellar Epithelial Cells of Germinating Barley (Hordeum vulgareL.)

Abstract

Chaffey, N. J. and Harris, N. 1985. Localization of ATPase activity on the plasmalemma of scutellar epithelial cells of germinating barley (Hordeum vulgare L.).—J. exp. Bot 36: 1612–1619. ATPase activity has been localized at an ultrastructural level in the absorptive region of the scutella of germinating barley (Hordeum vulgare L.). The enzyme is localized on the plasmalemma of the epithelial cells. Using the Gomori reaction the deposition of reaction product on the plasmalemma, which is dependent upon the presence of supplied ATP, was precluded or reduced by the inhibitors orthovanadate, mercuric chloride and DCCD, whilst β-glycerophosphate would not act as an alternative substrate. The mitochondria demonstrated phosphatase activity with both ATP and β-glycerophosphate as substrate. The results are discussed in relation to the active uptake of metabolites by the scutellum during germination and the structural modification of the plasmalemma of the epithelial cells to form plasmatubules.