With rapid progress in obtaining gene sequences for several plant species, the major challenge in plant genomics will shift to analysis of the functions of genes and the proteins they encode. This task will be especially challenging for the numerous genes whose function cannot be predicted based on sequence similarity to genes of known function in other organisms. Undoubtedly, this problem will be most obvious in areas where plants are unique, for example, in plant cell wall biosynthesis. Although other organisms such as bacteria and yeast have cell walls, their walls are fundamentally different in composition, structure, and function from those of plant cells, and therefore what is learned in those systems is not readily transferable to the study of plants.
Biochemical approaches have been largely unsuccessful in identifying the components associated with cell wall biosynthesis. However, genomic approaches are well suited to addressing the problems of identification and functional characterization of plant genes responsible for hemicellulose biosynthesis. Several strategies are available for identifying the genes whose products are putatively involved in cell wall biosynthesis and for developing testable hypotheses regarding their biochemical function.
This award will support the analysis of a cell wall biosynthesis in a representative dicotyledonous and monocotyledonous plant. Such a comparative study is justified because hemicelluloses from these different groups of plants are structurally distinct. The dicot will be Arabidopsis, the preeminent model dicot for experimentation, and the monocot will be maize, also an excellent plant for genetic, biochemical, and genomic research. The specific objectives are to: (1) identify candidate genes for cell wall biosynthetic enzymes; (2) analyze candidate genes for possible involvement in hemicellulose biosynthesis; and (3) investigate the function of specific genes. The award will support a comprehensive analysis of hemicellulose biosynthesis in plants that will integrate a variety of modern biological methods and concepts, including bioinformatics, polysaccharide biochemistry, cell and molecular biology, and genetics.
