Figure 2.

Nonuniform Reduction of Secondary Wall Thickness in Fiber Cells of the fra3 Mutant.

Fibers and vessels from the bottom internodes of 8-week-old plants were sectioned and examined for their wall thickness under a transmission electron microscope. en, endodermis; if, interfascicular fiber; v, vessel; xp, xylem parenchyma. Bars = 5.3 μm in (A) and (C) and 2.4 μm in (B), (D), (E), and (F).

(A) and (B) Wild-type interfascicular fibers showing uniformly thick walls. High magnification of the walls is shown in (B).

(C) and (D) fra3 interfascicular fibers showing nonuniform reduction of secondary wall thickness. High magnification of the walls is shown in (D).

(E) and (F) Vessel walls were slightly thinner in fra3 (F) than in the wild type (E).