Fungal cell wall synthesis and assembly.

Abstract

The importance of cell walls must not be underestimated. Once considered to be a nonliving excretion of the cell, its importance for maintaining cell viability is now fully established. Cell walls are essential structures of most eukaryotic organisms and nearly all prokaryotes. As clearly stated by Bartnicki-Garcia (19), “Three of [the] five kingdoms [proposed by Whittaker] (Monera, Fungi and Plantae) are made almost entirely of walled organisms. And in a fourth one (Protista) cell walls are essential in some stage in the life cycle of a majority of the species. Clearly, in members and variety, the walled kingdoms dominate the biological world.” It is evident that during evolution the acquisition of a wall permitted the cells to survive in aqueous environments with dilute solute concentrations and to colonize media otherwise harmful for naked wall-less cells. Evolution of the cell wall to the impressive fabric of interwoven polysaccharide microfibrils that surround some eukaryotic organisms, including fungi, undoubtedly represented a breakthrough that permitted the appearance of large multicellular organisms, of which trees represent the epitome. The success of this cell wall is evidenced by its conservation and wide distribution in organisms of today.