Plant & Animal Genomes XIII Conference

January 15-19, 2005
Town & Country Convention Center
San Diego, CA

Analysis Of Global Gene Expression During Fiber Initiation In Cotton

A. Bulak Arpat , Brad Sickler , Thea A. Wilkins

  Department of Agronomy and Range Science, One Shields Ave. University of California, Davis, CA 95616-8515

Developing cotton fibers provide a unique single-celled model system for studying fundamental biological processes in plants. Of long-standing interest are the molecular events that regulate the rate and duration of fiber expansion, and that in turn, determine important agronomic properties such as fiber length. The metabolic activity of fibers undergoing rapid polar elongation is reflected in the complexity of the fiber transcriptome. Expression profiling of the fiber transcriptome using long oligonucleotide arrays uncovered the existence of developmental switches that control fiber morphogenesis. The stage of rapid fiber elongation in developing fibers is accompanied by changes in transcriptional activity, protein complexity, and rate of growth. In our fiber model, spatial and temporal regulation of ~2500+ fiber genes at the transcriptional level parallels the rate and duration of fiber elongation. A subset of these temporally regulated genes encode major isoforms of functionally important genes that may well account for the bulk of genetic variability associated with major QTLs for fiber quality, and as such, provide prime candidate genes for functional analysis as well as genetic mapping and marker-assisted selection. Progress towards development of predictive models to guide genetic enhancement of fiber using molecular approaches will be highlighted.