Fig. 2.

Experimental work flow used for analyzing the phosphoproteome of the growing zone of maize leaves. Each biological replicate was individually analyzed relative to an internal standard. The internal standard was designed by pooling equivalent amounts of digested peptides from all analyzed plants. Peptide samples were then submitted to prefractionation prior to phosphopeptide enrichment. Phosphorylated peptides were analyzed using LC-MS/MS and relative quantification was achieved by XIC extraction.