Figure 2. Efficient SILAC labelling of Arabidopsis seedlings and assessment of arginine-proline conversion.

Mass spectra of unlabelled (“light”) and labelled (“heavy”) peptides of L37-2 ribosomal protein showing efficient labelling (SILAC ratio = 1.0023) (A). Mass spectra of “light” and “heavy” (heavy proline) peptides of an RNA helicase protein (B).