Figure 4: Hierarchical clustering of phosphoproteins.

(a) Phosphopeptides were standardized to zero-mean-unit-variance (z-scores). In the cluster analysis several groups are altered in their phosphorylation state in the snrk1α1/α2 mutant (e.g. cluster 1, 2 and 3) and they are further discussed in the text. (b) Phosphopeptide abundance of chloroplastic proteins. Phosphopeptide abundance of 3 replicates were averaged and normalized to the abundance of the wild type value at the time point 0 min of extended night, the ratios were Log2 transformed. Asterisks indicate significant differences between snrk1α1/α2 and wild type at each time point (*p < 0.05, **p < 0.01, ***p < 0.001).