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Membrane ATPase Activity of Barley Roots and Potassium Uptake by Isolated Stele and Cortex
Author(s) -
NASSERY H.,
VALAMANESH A.
Publication year - 1978
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.1399-3054.1978.tb04109.x
Subject(s) - stele , potassium , vacuole , cortex (anatomy) , parenchyma , chemistry , incubation , biophysics , biology , biochemistry , botany , cytoplasm , organic chemistry , neuroscience
Uptake of potassium ions by isolated stelar tissues of barley from 0.5 and 10 m M K + was respectively 13 and 3.6% of that of the cortical tissues. 0.1 m M H 2 PO 4 , LO m M ATP and 10 m M Ca(NO 3 ) 2 did not increase the potassium uptake of either stele or cortex during 5 h of uptake period. A time‐course incubation for histological demonstration of the ATPase activity of the plasmalemma and tonoplast of the matured sections of the roots demonstrated a greater activity for the cortical than the stelar tissue. In the stelar parenchyma cells, the plasma lemma showed a higher activity than the tonoplast. These results, which support the “leakiness hypothesis” of the stele, are discussed in relation to the proposed mechanisms of radial ion transport in roots.