Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

Gene Expression And Network Dynamics During Embryo Development In Brassica And Arabidopsis

Raju Datla¹ , Daoquan Xiang¹ , Edwin Wang² , Prakash Venglat¹ , Kumuda Kushalappa¹ , Lianglu Wan¹ , Andrew Ross¹ , Wilf Keller¹ , Gopalan Selvaraj¹

¹  Plant Biotechnology Institute, National Research Council of Canada, 110 Gymnasium Place, Saskatoon, SK S7N 0W9, Canada

²  Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada

Embryogenesis is an important developmental phase in the life cycle of seed plants. During this phase, the zygote undergoes a well-ordered series of cell divisions, followed by region-specific cell differentiation leading to an embryonic body plan, which includes the establishment of shoot and root apical meristems, central axis, cotyledons, and the hypocotyl. Though genetic screens have identified number of patterning and lethal mutants associated with embryo development in Arabidopsis, other key genes expressed during embryogenesis that play important functions are largely not known. To address gene expression patterns during the key stages of Brassica embryogenesis, embryos isolated from zygote to mature stages have been used in the construction of stage specific cDNA libraries and generated ~70,000 ESTs. These ESTs represent broad functional groups and some stages specific expression patterns. As a complimentary approach to ESTs, the Arabidopsis gene chips were used to profile expression patterns during the key phases of embryo development in B. napus and Arabidopsis. The microarray analyses identified ~2,000 differentially regulated genes during embryogenesis. Proteome studies in globular to mature stage embryos identified ~3,500 proteins in Brassica and Arabidopsis. We have used these genomics and proteomics datasets and developed framework for pathways and metabolic networks that operate during embryogenesis. The functional implications of the findings to embryo development in Brassica and Arabidopsis will be discussed.