Cells produce transient calcium spikes in response to numerous environmental and developmental signals. Calcium dependent kinases play a role in transducing various calcium spikes into downstream protein phosphorylation profile. To convert the calcium code into PTM code or phosphoproteome and cellular events in a specific signaling pathway, we have established and applied a quantitative PTM proteomics to decipher the PTM code in Arabidopsis. The proposed project will require students to perform some physiological experiments and protein and peptide isolation and conduct MS analysis of PTM peptides.