Updated publication reference for PubMed record(s): 27462335. Clock-generated biological rhythms provide an adaptive advantage to an organism which results in increased fitness and survival. To better elucidate the plant response to the circadian system, we surveyed protein oscillations in Arabidopsis seedlings under constant light. Using large-scale two-dimensional differential in-gel electrophoresis (2D-DIGE) the abundance of more than one thousand proteins spots was reproducibly resolved, quantified and profiled across a circadian time series. A comparison between phenol-extracted samples and Rubisco-depleted extracts identified 70 and 39 rhythmically-expressed proteins, respectively.