Ultrastructure and Topochemistry of Plant Cell Wall by Transmission Electron Microscopy

Plant cell walls are typically described as complex macromolecular composites consisting of an ordered array of cellulose microfibrils embedded in a matrix of noncellulosic polysaccharides and lignin. Generally, the plant cell wall can be divided into three major layers: middle lamella, primary cell wall, and secondary cell wall. Investigation of plant cell walls is complicated by the heterogeneous and complex hierarchical structure, as well as variable chemical composition between different sublayers. Thus, a complete understanding of the ultrastructure of plant cell walls is necessary. Transmission electron microscopy (TEM) has proven to be a powerful tool in elucidating fine details of plant cell walls at nanoscale. The present chapter describes the layering structure and topochemistry of plant cell wall revealed by TEM.