Figure 8.

Gene Expression Analysis of FRA3 Using the GUS Reporter Gene.

The FRA3 gene, including a 2-kb 5′ upstream sequence and the entire exon and intron region, was ligated in frame with the GUS reporter gene and transformed into wild-type Arabidopsis. Various organs from the transgenic plants were stained for GUS activity. fp, fiber precursor; if, interfascicular fiber; pi, pith; x, xylem. Bars = 165 μm in (E) to (G) and 330 μm in (H).

(A) and (B) Primary root (A) and cotyledon (B) from 3-d-old seedlings showing the GUS staining in all tissues.

(C) Leaf from 10-d-old seedlings showing the GUS staining in mesophyll cells and veins.

(D) Flower showing the GUS staining in various floral parts.

(E) Section from young elongating internodes showing GUS staining in all tissues.

(F) Section from internodes at the stage near the cessation of elongation showing intensive GUS staining in vascular bundles and interfascicular regions.

(G) Section from nonelongating internodes showing the GUS staining predominantly in vascular bundles and interfascicular fibers.

(H) High magnification of (G) showing fiber cells with thick secondary walls and strong GUS staining.