Transmission and Scanning Electron Microscopy for Plant Protoplasts, Cultured Cells and Tissues

Abstract

Electron microscopy is an important tool for studies of plant structure. Electron microscopes utilize focused electron beams rather than visible light and are capable of resolving or detecting much finer details than the light microscope. Two types of electron microscope have been used to study plant cells in culture, the transmission (TEM) and scanning (SEM) electron microscopes. With the TEM, the electron beam penetrates thin slices of biological material and permits the study of internal features of cells and organelles. The TEM has been particularly important for basic studies of the structure and function of plant cell organelles such as microtubules and coated vesicles, examining polyethylene glycol-induced fusion of protoplasts, and monitoring internal changes during the development of cultured explants (e.g., Fowke 1989; Fowke et al. 1985, 1991). The electron beam of the SEM scans the surface of prepared specimens. Thus, the SEM is important for studying the external morphology of intact cells, tissues and organs and is capable of resolving details intermediate in size between those detected by the light microscope and the TEM.