Figure 5.
Relationship between vacuolar (p − b)/b ratios for calcium and strontium of different cell types in an excised leaf from rough lemon grown under low-calcium conditions and fed 25 mm Sr(NO3)2 and 25 mm Ca(NO3)2 through its petiole for 24 h. Results from 65 cells in one leaf. Values of (p − b)/b ratios were adjusted for the different sensitivities of the XRMA to calcium and strontium, so the slope of the line reflects the molar accumulation ratio of the two elements (see “Materials and Methods”). The fitted regression line is shown (y = 1.16x − 0.003; r2 = 0.962).