Fig. 3.

Relative quantification of 12 CCM proteins detected in low-CO₂-adapted pyr+ (black) and pyr– (grey) strains using LC-MS/MS. CCM and CO₂-responsive proteins (A, C), non-CO₂-responsive (rbcL), and photosynthetic/control (PSBO) proteins (B, D) are shown. Note the different scales of the y-axes. Two measures of protein abundance were used: label-free (ion) intensity, which is proportional to absolute abundance (A, B), and spectral count, which is a measure of the relative abundance in the sample (C, D). Values shown are the mean and standard error of six measurements (two technical replicates for three replicate cultures). Asterisks represent statistically significant differences (P<0.05) in protein abundance between the two strains according to a t-test on label-free intensity values or a G-test on spectral counts.