With the advent of the DNA microarray technology, it became possible to study the expression of entire cellular genomes. Tanscriptional profiling alone can not provide a comprehensive picture of the cellular physiological state and it should be complemented by other cellular fingerprints. Transcriptional profiling combined with metabolic information of a systematically perturbed system can unravel the relationship between gene and metabolic regulation. In this context the transcriptional response of Arabidopsis thaliana liquid cultures (grown for 12 days under light and 23 sup oC) to 1-day treatment with 1% CO sub 2 was measured by full genome cDNA microarrays. The Time series gene expression profiles were analyzed in the context of the known Arabidopsis thaliana physiology using multivariate statistics. Data analysis revealed an increase in the rate of CO sub 2 fixation, biomass production and cell wall growth. The breadth of the information obtained from a single experiment validated the significance of the high throughput transcriptional profiling.