Figure 7.

Effect of Homogeneous or Localized Fe Supply on Cell Division, Differentiation, and Elongation.

(A) Seedlings of a ProCYCB1;1:GUS line were germinated on Fe-deficient medium and transferred to segmented agar plates supplemented with 75 μM ferrozine and with the indicated Fe(III)-EDTA concentrations only in the middle segment (localized supply) or in all three segments (homogeneous supply). After 7 d, lateral roots from the middle segment were assayed for GUS activity ([A], left panel) and length of rhizodermal cells ([A], right panel). Arrowheads indicate the boundaries of two consecutive epidermal cells. Bars = 25 μm.

(B) and (C) Length of lateral root meristems (B) and length of individual rhizodermal cells (C). Bars represent means ± se; n = 3 to 4 lateral roots from >14 seedlings. Asterisks denote a significant difference according to Student’s t test (P < 0.01).