Figure 1.

Polysome Loading over a Diel Cycle.

Ten-day-old wild-type and CCA1-ox seedlings were grown in a 16-h-light/8-h-dark cycle. Tissue extracts from five time points harvested every 6 h were individually subjected to polysome density gradient centrifugation. The fraction of total RNA recovered in polysomal fractions (small and large polysomes) is plotted in (A) as a percentage of total RNA (nonpolysomes and small and large polysomes shown in [B] and [C]) at each ZT time. Error bars show standard deviations from three biological replicates. The difference in polysome loading between the wild type and CCA1-ox was significant by unpaired two-tailed t test for ZT6 (P = 0.0058) and ZT18 (P = 0.0041). The elevated polysome loading compared with ZT0 was significant in the wild type for ZT6, ZT12, and ZT18 and in CCA1-ox for ZT6.