Dramatic improvements in nucleic acid sequencing and information technologies over the past decades have made it routine to generate genomescale datasets enabling the descriptive evaluation of biological systems at a molecular level. Genome sequencing provides an unprecedented molecular blueprint for an organism, yielding evolutionarily-linked information about their potential metabolic and physiological behavior. The desire to extend

Departments of Horticultural Science and Plant Biology, Microbial and Plant Genomics Institute, University of Minnesota-Twin Cites, 305 Alderman Hall, 1970 Folwell Avenue, Saint Paul, MN 55108, USA; e-mail: [email protected]

this analysis beyond the “blueprint” to high-throughput analysis of the molecular changes underlying macroscopic behavior has spawned parallel descriptive approaches that extend along the canonical fl ow of biological information (DNA RNAs proteins metabolites) by extension from genomics. High-throughput analytical disciplines have emerged in the order of this information fl ow including: genomics, transcriptomics, proteomics and metabolomics, which together constitute what is referred to as the “omics cascade” (Dettmer et al. 2007). The omics cascade provides the methodological core of systems biology-the goal of which is to make large numbers of unbiased molecular observations to construct descriptive models of biological systems that can be used to link molecular observations with macroscopic or behavioral properties of a system (Kell 2006).