Sodium and Potassium Interactions in Increasing the Salt Tolerance of Atriplex halimus L.: II. Na+ and K+ Uptake Characteristics
- Ahmad Mozafar,
- J. R. Goodin and
- J. J. Oertli22
Absorption of Na+ and K+ by Atriplex halimus from solutions with varying concentrations of Na+, K+, or Na+ + K+ were studied. In contrast to most plants, Na+ absorption by A. halimus was not inhibited by high concentrations of K+ in the culture solution. On the other hand, K+ absorption was greatly reduced by excess Na+ in the growing medium. If Na+ and K+ were present at equal concentrations, Na+ uptake was twice as great as K+. A specific site for Na+ absorption which is not inhibited by excess K+ in A. halimus was postulated. The results of previously reported work, in which it was shown that the presence of equal parts of Na+ and K+ in the culture solution resulted in the tolerance of plants to lower external osmotic potential and also higher yield, was discussed in light of the presence of higher Na+ and K+ content of the leaves. The presence of a biochemical interaction between Na+ and K+ which becomes operative only when both ions are present in adequate amounts is postulated. Higher yields and tolerance to lower external osmotic potential are thought to be the final manifestation of such a biochemical interaction.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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