Figure 7

Activity of the Synechocystis Yfr2a promoter under various conditions. A. Fluorescence emitted from cultures with luciferase expression driven by the Yfr2a or the psbA2 (slr1311) promoter under standard growth conditions. All promoter fragments were used in the correct (5') or inverted (3') orientation with two independent clones each. Average absolute luminescence values together with standard deviations from three replicate measurements for each clone are shown. B. Measurement of luciferase activity 20 min after application of two different light treatments, transfer of cultures to 150 and 1,000 μmol photons s^-1 m^-2 for 15 minutes. C. Heat stress; expression was measured 20 min after exposure to 43°C for 10 min. D. Cold temperature stress; expression was measured 20 min after exposure to 12°C for 10 min. All measurements were performed with two independent clones in three replicates each. In B, C and D the values from the untreated controls were set to 100%. All cultures grew in late logarithmic phase during the measurements.