Figure 2.

ABI4 Expression in Roots.

(A) to (J) Expression patterns in roots.

(A) Two-week-old Arabidopsis seedlings expressing ABI4:GUS stained histologically for GUS activity.

(B) to (G) Enlarged views of different developmental stages of the PRs and LRs (from top to bottom regions).

(B) Mature PR near the shoot-root junction.

(C) Mature LR.

(D) Newly developed LR.

(E) Emerging LR.

(F) Root hair zone. Note the expression gradient within this zone.

(G) Root tip and meristematic zone.

(H) Section of GUS-stained mid-upper zone (8 mm from the shoot-root junction) of PR counterstained with ruthenium red.

(I) Cross section of PR in the upper zone (3 mm from the shoot-root junction), treated as in (H).

(J) Colored scheme indicating the different cell types in the section depicted in (I).

Bars = 1 mm in (A), 50 μm in (B) to (H), and 10 μm in (I) and (J).