Changes During Recovery from Sodium Deficiency in Atriplex

Although the concentration of sodium in leaves of Atriplex plants increased rapidly after receiving sodium, no growth response was detectable for about 6 days. It was found that respiration rate increased to its maximum within 3 days. Chlorophyll content also increased from an early stage, whereas the concentrations of sugars and starch did not increase, and ratios of soluble to total nitrogen did not decrease until later.The respiratory response appears to be specific to sodium as different salts of sodium caused similar responses, and no other univalent cation substituted for sodium. In addition, both growth response and respiration rate tended towards their maxima with the same concentration of applied sodium. The rate of anaerobic CO(2) production increased when sodium was fed to leaves, suggesting that the effect of sodium is in the glycolytic sequence.