Figure 6.

Leaf sap osmolality and the combined concentration of K⁺, Na⁺, and Cl^– in relation to the total concentration of polar metabolites. Leaf samples were taken at midafternoon. Leaf K, Na, and Cl were measured, and the combined concentration of K⁺, Na⁺, and Cl^– was calculated on the basis of leaf water content by assuming that they were all in their ionic forms. Regression equations are as follows: for leaf osmolality, y = 1.438x + 297.80 (r² = 0.80, P < 0.0001, n = 45); for concentration of ions, y = 0.166x + 189.83 (r² = 0.12, P = 0.021, n = 45).