Figure 1.

The time course of total amounts of phenolic compounds secreted from roots in response to Fe deficiency. Seedlings were grown at 0 (−Fe) and 20 μm FeEDTA (control) with a cycling of 1 d in the nutrient solution and the following day in 0.5 mm CaCl₂ solution. The total phenolics content in 0.5 mm CaCl₂ solution was measured by Folin-Ciocalteu's reagent. Data are means ± sd (n = 3).