Plant & Animal Genome IX Conference

Poster: Genes & Pathways
P07_35.html

FUNCTIONAL GENOMICS OF HEMICELLULOSE BIOSYNTHESIS IN CEREALS

MSU-DOE Plant Research Laboratory, Michigan State Univeristy, East Lansing, MI, 48824, USA

Hemicellulose is an abundant complex polysaccharide found in the primary cell walls of plants. The unique cell wall composition of plants and the difficulty inherent in the chemical analysis of carbohydrates has lead to a dearth of information on cell wall synthesis. Using a functional genomics approach, we seek to better understand the biosynthesis of glucuronoarabinoxylan and mixed-linked glucans, the hemicelluloses found in cereals. Our identification of candidate genes is based on bioinformatics and microarray analysis. Several groups of genes have been identified based on their similarity to the cellulose synthase genes previously identified in cotton and Arabadopsis. These genes, known as cellulose synthase-like (Csl), belong to two primary groups. We are attempting a functional analysis of the Csl genes by transforming rice callus with constructs designed to express double-stranded RNA. The cell wall composition of mutant callus will be analyzed. Other candidate genes are being identified using microarray analysis of various maize tissues. Target tissues include light versus dark treated mesocotyl, gravistimulated stem, and developing cob. We hope to identify glycosyltransferases and polysaccharide synthases involved in cell wall synthesis and in doing so add to our understanding of plant growth and development, response to biotic and abiotic stress, and aid in the biotechnological improvement of food, fiber, and fuel.