Fig. 2.

ARI12 expression in cop1-4 under white light, low and high fluence rate UV-B. (A) 12 day old seedlings treated with low fluence rate UV-B (LFR) for 1 h, 3 h and 6 h as described by Favory et al. (2009). (B) 25 day old plants under white light (WL) harvested at 9:00, 12:00, 14:00, 16:00, and 18:00. The harvesting time points are identical with that of the high fluence rate (HFR) UV-B experiments in (C). (C) 25 day old plants exposed to WL supplemented with HFR UV-B (4 μmol m⁻² s⁻¹) for 90 min. ARI12 expression was normalized to the reference gene TUB9. ctr: before UV-B; im: immediately or 2 h, 4 h, 6 h after completing the 90 min UV-B exposure. Error bars indicate standard errors. * and ** correspond to p-values ≤0.05 and ≤0.001, respectively.