Plant Cell Walls
Dr. Markus Pauly
New Position: Associate Professor, Energy Bioscience Institute, Berkely, California
The group focuses primarily on the function, synthesis, metabolism and signalling of plant cell wall polymers using molecular genetic and structural approaches.
The main aim is to relate the structural features present in the complex polysaccharide networks of plant cell walls to the diversity of functions that this extracellular matrix is responsible for. Our research is addressing this question by manipulating the biosynthetic and metabolic machinery of the walls in planta in an attempt to generate plants with an altered wall structure and subsequently assess the performance of the plant. The work is focused on the various non-cellulosic polysaccharide networks present in the primary cell wall, i.e. xyloglucans and pectic polysaccharides. Arabidopsis is the main model system, but tomato and rice are also used.
Higher plant cells are encased in cell walls that define their shape and contribute to the strength and structural integrity not only of individual cells, but also of the entire plant. Despite its necessary rigidity, the cell wall is a highly dynamic entity that is metabolically active and plays crucial roles in diverse cell activities such as growth, differentiation, cell-to-cell communication and transport, senescence, abscission, and plant-pathogen interactions.
The wall can be described as a liquid crystal (Fig. 1): Microcrystalline cellulose is embedded in a hydrated matrix consisting of coextensive networks of complex heteropolysaccharides and sometimes glycoproteins. Cell walls also constitute renewable resources and are often present in by-products of industrial production, such as pulps. Genetic engineering of crop plant cell walls can identify biopolymers with novel functional properties, as well as simplify their extraction, thus increasing the value of these "waste-products".