In the post-genomic era, one of the most important goals for the community of plant biologists is to take full advantage of the knowledge generated by the Arabidopsis thaliana genome project, and to employ state-of-the-art functional genomics techniques to assign function to each gene. This will be achieved through a complete understanding of what all cellular components do, and how they interact with one another to produce a phenotype. This book discusses the findings about the function of proteins belonging to the Arabidopsis SABATH family, by applying a combination of genomics tools, including genome-wide expression analysis and gas-chromatography coupled with mass spectrometry-based metabolite profiling. These results combined with available biochemical information, provide a better understanding of the physiological role of SABATH methyltransferases, further insights of secondary plant metabolism and deeper knowledge of the consequences of modulating the expression of SABATH methyltransferases, both at the gene expression and metabolite levels.