Arabidopsis thaliana as a model system to study synthesis, structure, and function of the plant cell wall

The cell wall of higher plants has been studied in numerous species using methods of carbohydrate chemistry, biochemistry and cell biology portraying the wall as a dynamic structure composed of highly complex polysaccharides and structural proteins encoded by multi-gene families. The recent discovery of proteins involved in cell wall loosening has provided opportunities to elucidate the mechanism of extension growth. Genetic tools have rarely been used to analyze the function of these proteins in viva, or to identify genes involved in the synthesis of cell wall polysaccharides. It has recently been demonstrated that mutants with changes in cell wall composition can be isolated in Arubidopsis thaliana opening possibilities to clone genes involved in the synthesis or modification of cell wall material via map-based approaches. The number of Arubidopsis mutants in cell wall synthesis is very limited, suggesting that novel screening procedures are required to come closer to the goal of saturating cell wall biosynthetic pathways. The availability of large numbers of expressed sequence tags in combination with collections of T-DNA and transposon-tagged Arubidopsis lines offers a considerable potential for the genetic characterization of cell wall-related genes which can be identified via database searches. The recent identification of Arubidopsis genes involved in the synthesis of cell wall precursors, and the discovery of plant homologs to bacterial cellulose synthases offer numerous and exciting possibilities for the genetic dissection of cell wall synthesis in higher plants using Arubidopsis thulium as a model system. 0 Elsevier, Paris.