Figure 1. Analysis of thylakoid carbonic anhydrase (Cah3) activity and expression during the acclimation of high-CO₂-grown C. reinhardtii cells to low CO₂ conditions.

(A) CA activity (WA units (mg Chl)⁻¹) was measured in thylakoid membranes isolated from high-CO₂-grown cells or acclimated to low CO₂ for 2, 4 and 8 h. Values are means ± SE (n = 5). (B) Semiquantitative RT-PCR analysis of Cah3 gene expression. Total RNA to be used for RT was isolated by using Trizol™ reagent according to the manufacturers protocol (Life Technologies, US). Aliquots of the reaction mix were loaded and ethidium bromide stained in 1% agarose gels. (C) Immunoblot analysis of total cell extracts from cells of C. reinhardtii with antibodies raised against over-expressed Cah3 polypeptide. The lanes were loaded with 10 µg protein.