FIGURE 4.

The CCA1-ox strain cannot sustain cycles of RPS6 phosphorylation if grown in continuous light. Seedlings of clock-deficient Arabidopsis (CCA1-ox) were entrained in a light-dark cycle for 11 days, then shifted to continuous light for another four and a half days. Sampling began at ZT30 on the second day in continuous light. Seedlings were grown on medium lacking sucrose (A–C) or containing 1% sucrose (D–F). (A,D) Representative immunoblots for S237-P and S240-P and total RPS6. (B,C,E,F) Immunoblot signals for S237-P and S240-P were quantified and normalized against total RPS6 signals from the same time point, followed by median-centering each data series and averaging of the multiple replicates. Error bars show the standard error of the mean from n = 2 replicates.