Abstract
Plant cells have numerous single-membrane organelles such as the Golgi body, vacuole, and endosome. Components such as cargo proteins and lipids are transported between these single-membrane organelles and the plasma membrane in membrane trafficking. Recently, live imaging techniques using fluorescent tags and fluorescent tracers have enabled the detection of the organelles and vesicles. However, ultrastructures such as Golgi vesicle and endosome are not clearly detectable in the plant cell. Therefore, we are performing an exhaustive ultrastructural analysis of single-membrane organelles in Arabidopsis and tobacco roots using high-pressure freezing and electron microscopic techniques. We observed highly dense large vesicles derived from the Golgi body in epidermal cells but not in columella cells. Meanwhile, many clusters of vesicles were existed in columella cells but not in epidermal cells. Moreover, the number and structure of the multi-vesicular body and Golgi body varied in columella cell layers. Here, we will mainly discuss columella cells.
