(A) RVE8 expression in Col, toc1-4, lux-1 and CCA1-OX in LD. 7-day-old seedlings were collected at the times indicated and qRT-PCR was performed. Data are double-plotted to facilitate visualization. Values represent mean ± SEM. (B) Transcript levels of PRR5, PRR7 and PRR9 at ZT 0 (when RVE8 transcript levels normally peak) in wild-type (Col), toc1-4, lux-1, and CCA1-OX. Expression levels are normalized to PP2A. Data are represented as mean ± SEM from three technical replicates. (C) A proposed clock model integrating RVE8 as an activator of evening clock genes. The relative time of action of each component during diurnal cycles is shown from left to right. White box: day, grey box: night. REVEILLE/CCA1/LHY family proteins are shown in yellow; pseudo-response regulators are shown in blue; the evening complex components are shown in green. Clock components with one or more EE in their promoter regions are marked with red boxes. Red solid arrow: activation, red dashed arrow: activation only displayed in specific condition (red arrows are based on the current study), black perpendicular bars: repression, black arrow: activation. In this study, we demonstrated that RVE8 directly activates multiple evening-phased clock and output genes and that RVE8 is regulated by TOC1, LUX and CCA1, likely indirectly through their control of PRR5, 7 and 9 expression. For clarity, only transcriptional regulation is represented.