Figure 4.

Cell Cycle Arrest and Lateral Root Initiation in the Double nrp1-1 nrp2-1 Mutant.

The wild-type and the nrp1-1 nrp2-1 mutant plants containing the G2/M marker CYCB1:GUS were analyzed by histochemical staining for GUS activity. Bars = 50 μm.

(A) and (B) Primary root tips of 6-d-old seedlings of the wild type and the mutant, respectively.

(C) and (D) Primary root tips of 8-d-old seedlings of the wild type and the mutant, respectively. Two representative examples are shown for each.

(E) and (F) Lateral root formation in the wild type and the mutant, respectively. Representatives of early to late stages of lateral root formation are shown in panels from left to right. Observations were performed on primary roots of 6- to 12-d-old seedlings.