Self‐assembly of plant cell walls

The object of this paper is to define criteria for distinguishing between self‐assembly and template‐based assembly in plant cell walls. The example of cellulose shows that cell wall polymers biosynthesized at a membrane may retain parallel chain packing arrangements that are thermodynamically unstable and cannot be reproduced in vitro, making the experimental testing of the self‐assembly hypothesis difficult. Also, natural cellulose is ordered on a number of scales of pattern, each of which may be constructed by either self‐ or template‐based assembly independently of the rest. These conceptual problems apply equally to the self‐assembly of complete cell walls and other cell wall polymers. It is suggested that the self‐assembly concept should be applied only to one stage or level in the synthesis of a cell wall, and that an additional concept of parallel assembly may be useful for understanding the synthesis of some polysaccharides.