Electron Micrographs, a Tomographic Slice Image, and Tomographic Reconstructions of the Cortical Cytoplasm of High-Pressure Frozen and Freeze-Substituted Columella Cells from Arabidopsis, N. tabacum, and M. sativa.
(A) and (B) Electron micrographs of statoliths (amyloplasts) in close physical contact with cortical ER cisternae in columella cells of Arabidopsis (A) and N. tabacum (B). Note the deformation of the ER membranes in the contact region.
(C) Tomographic slice image of a statolith (amyloplast) that has deformed an ER cisterna of the cortical ER network adjacent to the cell wall in a columella cell from M. sativa.
(D) to (F) The tomographic models show the tubules and cisternae of the cortical ER network and the statolith-induced deformation of the ER membrane from different viewing angles. The deformed ER region (F) is highlighted (orange), and the arrows ([C] to [F]) indicate the direction of the statolith impact. AM, amyloplast; PM, plasma membrane; CW, cell wall. Bars = 300 nm.