Cellulose synthesis: Cloning in silico

Cell walls are of interest to plant biochemists and cell biologists for two main reasons: they regulate cellular morphogenesis and act as structural support materials. As it is a major component of plant cell walls and a natural product of considerable commercial value, cellulose has long been a focus of interest in cell-wall biology, although it is far from the only constituent of cell walls. During the last several decades, extensive investigations of the organization and structure of plant cell-wall polysaccharides by a variety of microscopic and analytical methods have provided ample evidence that cell walls are chemically complex, dynamic structures. These studies have, however, provided little insight into how the walls are constructed or the functional significance of the various components. It has been estimated that several hundred enzymes are required to synthesize the major cell-wall polysaccharides [1]. Despite widespread interest, not a single gene directly required for the biosynthesis of any plant cell-wall polysaccharide has been unequivocally identified. Thus, the recent identification of candidate genes for cellulose synthase from cotton by Pear et al. [2] represents a major step forward in the field of cell-wall biology.