Fig. 2.

PIFs regulate metabolic signaling in the circadian system in Arabidopsis. (a–b) High light effects on PIF regulation of circadian rhythms. pifQ CCA1:LUC and wt CCA1:LUC lines were entrained on medium without sucrose before being transferred to (a) Rc of different fluences or (b) 60 μmol m⁻²s⁻¹ constant white light. (a) Luciferase activity and (b) leaf movements were plotted. The average of 3–4 independent experiments (a) n ≥66, (b) n ≥28. (b) The SEM was plotted, *** p<0.0001 (Student two-tailed t-test). (c–d) The effects of inhibiting photosynthesis on pifQ regulation of circadian rhythms. pifQ CCA1:LUC and wt CCA1:LUC lines were entrained on medium without sucrose before being transferred to 75 μmol m⁻²s⁻¹ continuous red light (Rc). Two days before transfer to Rc, two groups of seedlings were replanted on medium containing 20ZM DCMU (filled and open green triangles) or without DCMU (filled and open blue circles). d, shows wt and pifQ with DCMU plotted on a larger Y axis scale. The average of 2 independent experiments (n ≥40). *** p<0.001 (Student two-tailed t-test). The red and hatched bars represent subjective light and respectively.