Comparison of changes in gene expression between low and high abundant proteins, for each of the environmental conditions.

We identify the extreme group values for abundance and use the Mann-Whitney analysis for characterizing positive or negative associations with gene expression levels, as detailed in the methods section. Lower and Upper concentration thresholds indicates the cutoff limits for selecting low abundance proteins and high abundance proteins. A positive z indicates that proteins in the Lower group present higher up-expression and lower down-expression than those in the Upper group as compared by the Mann-Whitney analysis. A negative z indicates the opposite result. The corresponding p-values obtained using this test are indicated as (***) if p<0.05. Abundance is divided by 103 pr/cell.