Changes in abundance of mRNA for three PpSigs and psbD under DD. P. patens cells were maintained in LD for more than 2 weeks after which cells were harvested at indicated times during 48 h in DD. Abundance of mRNA was measured as described in legends for Figures 2 and 3. A, Changes in abundance of PpSig1, PpSig2, and PpSig5 mRNAs. White circles, PpSig1; black circles, PpSig2; white triangles, PpSig5. B, Changes in abundance of psbD mRNA. Black and gray hatched bars indicate dark intervals and subjective light intervals, respectively. We obtained similar results in two independent experiments.