Fig. 2
Development of a large-scale selected reaction monitoring (SRM) system targeting the tomato trichome gland cell (TGC) proteome. a Images of the TGC sampling procedure. The target TGCs from the head of type VI trichomes of tomato were manually recovered with a pair of fine forceps under a stereoscopic microscope. b Polyacrylamide gel electrophoresis (PAGE) of the TGC proteins. After sampling TGCs from 800 trichomes, cellular protein components were extracted. Protein extracts were separated using a 4–12% NuPAGE gel and protein bands were visualized with Bio-safe CBB. c Experimental workflow of the SRM assay development. Proteins separated by PAGE were digested in the gel; the resulting peptide digests were analyzed by liquid chromatography–mass spectrometry (LC–MS) and their sequences were identified by a database search. Based on the obtained MS information, the combination of a precursor ion and the fragment ions (SRM transition) was selected. Finally, for monitoring 750 peptides, 2 251 transitions were chosen in this study