High level of sequence similarity and genetic conservation within plants of same family allow us to use the informations and cDNA microarray obtained from a model plant such as Arabidopsis for better understanding of non-model plants within the same family, for example, rapeseed. Several lines of rapeseed plants with different sensitivity to cold stress were selected and the gene expression profiles under cold stress were examined using 1.6K specialized cDNA microarray. For the comparative analysis between Arabidopsis, economic plants and rapeseed, we adopted a recently developed computational method called "Gene Set Enrichment Analysis (GSEA)" which determines whether defined set of genes show statically significant and concordant differences between two biological states. Along this, five different gene sets including a network gene set based on a regulatory gene network model for early cold stress response and a co-expression gene set based on ∼ 1,500 expression data were built in this lab. With these gene sets and GSEA method, the expression data was analyzed to pinpoint the group of genes potentially responsible for the difference of stress sensitivity between two different plants. Since the plant encounters stress combinations concurrently or separated temporally and must present an integrated response to them, we built 'Cross-talk map' using ∼ 63 expression data of Arabidopsis under 9 different environmental stresses. Utilizing this cross-talk map, the significance of the identified group of genes was evaluated for their practical application to enhance stress tolerance. Currently, we identified several promising genes at a cross-talk point and are pursuing transgenic engineering to enhance the stress tolerance against more than two stress conditions.

• Dong-Hee Lee(Dept. Life Sciences, Ewha Womans University)