Some Observations on Absorption of Cesium by Excised Barley Roots.

Relative Uptake and Translocation of Potassium and Cesium in Barley.

The ability of plants to absorb ions selectively is a major reason for the preference for chemical rather than physical theories of ion uptake (11), yet in spite of this, comparatively little attention has been paid to this property. Thus far, selectivity between alkali cations has been examined in excised barley roots (6) in beet discs (12) and in whole plants (1,4). In recent years the relati...

Accumulation of Calcium in Exudate of Individual Barley Roots.

Metabolic absorption of Ca by plant roots has been reported to be extremely slow in comparison to the alk?li cationis ad Mg (A,77 14, 15, 16). In certain root tissues, metabolic absorption of Ca was difficult to detect if it occurred at all (1, 9, 14, 18). Since the intact plants of most species are known to take up a large amount of Ca, these results appeare(l to support the hypothesis of solu...

Respiration and Salt Absorption by Excised Barley Roots.

Calcium inhibition of potassium absorption in corn roots.

Calcium (or magnesium) sulfate or chloride was found to inhibit energy dependent potassium transport in excised corn roots. This Ca(2+) inhibition of K(+) transport was most pronounced during the initial phases of transport. As the absorption periods were lengthened the effect of Ca(2+) gradually changed from an inhibition to a typical promotion (after about 30-45 mins) of K(+) transport. Kinet...

Inhibitory effects of 2,3,5-triiodobenzoic Acid on ion absorption, respiration, and carbon metabolism in excised barley roots.

The ability of 2,3,5-triiodobenzoic acid (TIBA) to alter ion absorption, respiration, carbon metabolism, and the permeability of the cell membranes of excised barley roots has been examined. Roots pretreated in either H(2)O, KCl, or TIBA followed by treatment in KCl, TIBA, or KCl and TIBA demonstrated that inhibition of ion uptake due to TIBA was reversible. These studies also suggest that ions...