Quantification and inducibility of luciferase activity in transformants expressing the luciferase gene. Luciferase activity in transformants was assayed using a luminometer. The bars represent the mean of three independent experiments. The standard deviation is indicated. (A) Luciferase activity of pPsaD-GLuc derived transformants (PanTJ…) compared to the wild-type strain. (B) Luciferase activity of pHRLucP derived transformants (PanHR…) compared to the wild-type strain. (C) Luciferase activity of pHsp70A-GLuc derived transformants (PanHsp…) compared to the wild-type strain. (D) Fold induction of luciferase activity in heat-shocked transformants (39°C) compared to non-heat-shocked transformants. In pHRLucP-derived transformants (PanHR…) the luciferase is driven by the V. carteri hsp70A/rbcS3 tandem promoter. For pHsp70A-GLuc-derived transformants (PanHsp…) the luciferase gene is driven by the C. reinhardtii HSP70A promoter. The parental wild-type strain was analyzed as a control. Transformants and wild-type colonies were subjected to a temperature shift from 29°C to 39°C for 1 h. After a 15 min recovery phase at 29°C, cells were lysed, and luciferase activity was assayed. As a reference control, non-heat-shocked transformants were analyzed in an identical fashion.