Analysis of transcript abundance of the TOC1 circadian clock gene in transgenic (TG) and control Arabidopsis plants in long day conditions after DEX application. a) Relative TOC1 transcript accumulation is shown at ZT15 on Day 2, 28 h after DEX was applied to 15 day-old plants growing on agar plates in LD. b) Relative transcript accumulation is shown either 8 h (ZT16) or 16 h (ZT24) after DEX was sprayed onto plants growing in hydroponic media in LD. Plants were treated with DEX (+DEX) or control solutions (-DEX). Transcript levels were normalised to At2g32170 in a) or ACTIN2 in b). The data is presented as mean +/- SD for 3 qRT-PCR replicates. The black bars on the harvest scheme indicate night, the open bars indicate day and the grey bar indicates the length of treatment with DEX or control solutions, ZT0 is lights on.