Early flowering of rup2 in SDs supplemented with UV-B depends on the key flowering regulator CO. (A) Representative images of 100-d-old wild-type (Col), rup2-1, co-101, and rup2-1 co-101 Arabidopsis plants grown with (+) or without (−) UV-B. (B,C) Quantification of flowering time of wild-type (Col), rup2-1, co-101, and rup2-1 co-101 plants grown in SD with (+) or without (−) UV-B. The flowering time is represented by total leaf number (rosette and cauline leaves; B) and days to bolting (C). Error bars represent standard deviation. n = 21. Shared letters indicate no statistically significant difference in the means. P > 0.05.