Figure 6.

Electron Micrographs of High-Pressure Frozen and Freeze-Substituted Columella Cells from Tobacco and Arabidopsis.

(A) The amyloplast (statolith) volumes are occupied by polygonal-shaped, tightly packed, and lightly stained starch granules, which are surrounded by more darkly stained stroma material.

(B) Higher-magnification view of the boxed area in (A). The adjacent statoliths from N. tabacum are separated by an ∼30-nm gap, and the surface of one of the amyloplasts appears deformed at the contact site (arrowheads).

(C) The adjacent statoliths from Arabidopsis are separated by an ∼30-nm gap (arrowheads). AM, amyloplast. Bars = 500 nm.