Gene Expression Analyses for Elucidating Mechanisms of Hormonal Action in Plants

Analysis of large-scale gene expression data sets is proving to be a powerful tool for gene function prediction, cis -element discovery and hypothesis generation using Arabidopsis thaliana . Public initiatives led by the AtGenExpress Consortium and experiments conducted by individual researchers to document the transcriptome of Arabidopsis thaliana have led to a large numbers of data sets being made publicly available for data mining by so-called “electronic northerns”, co-expression analysis and other means. Given that approximately 50% genes in Arabidopsis have no function ascribed to them by “traditional” homology searches, and that only around 10% of the genes have had their function confirmed in the laboratory, these analyses can accelerate the identification of potential gene function with a mouse-click. This chapter covers the use of data mining tools available at the Bio-Array Resource (www.bar.utoronto.ca ) for hypothesis generation in the context of plant hormone biology.