Expression data from Arabidopsis thaliana seedlings

Light pulses at the end of the day or night be able to control the phase of the circadian clock. Pulses in the middle of the night has not effect on the circadian oscilations. To understand how the circadian clock gate the light signal in the middle of the night we used microarrays to characterize the light effect in the whole expression profile. Plants of Arabidopsis thalina (Columbia ecotype) were grown in 12/12 light/dark cicles for 15 days and then were tranfer to continuous dark . Plants were slplit in two groups. First group recieved 1hr light pulse in the middle of the night (Night treatment), second group recieve 1hr light pulse in the middle of the subjective day (Day Treatment). Samples of both groups were collected without light pulse named as a control.