Arabidopsis proteomics: a simple and standardizable workflow for quantitative proteome characterization.

Arabidopsis is the model plant of choice for large-scale proteome analyses, because its genome is well annotated, essentially free of sequencing errors, and relatively small with little redundancy. Furthermore, most Arabidopsis organs are susceptible to standard protein solubilization protocols making protein extraction relatively simple. Many different facets of functional plant proteomics were established with Arabidopsis such as mapping the subcellular proteomes of organelles, proteo-genomic peptide mapping, and numerous studies on the dynamic changes in protein modification and protein abundances. As most standard proteomics technologies are now routinely applied, research interest is increasingly shifting towards the reverse genetic characterization of gene function at the proteome level, i.e., by profiling the quantitative proteome of wild type in comparison with mutant plant tissue. We report here a simple, standardizable protocol for the large-scale comparative quantitative proteome characterization of different Arabidopsis organs based on normalized spectral counting and suggest a statistical framework for data interpretation. Based on existing organellar proteome maps, proteins can be assigned to organelles, thus allowing the identification of organelle-specific responses.