Representative seedlings (A, C) and hypocotyl lengths (B, D) of 6-day-old transgenic seedlings of indicated genotypes. Seedlings were grown in dark or continuous blue (25µmol m−2 s−1), red (15µmol m−2 s−1), and far red (5µmol m−2 s−1) light for 6 days, and hypocotyl lengths of indicated genotypes were measured (n ≥ 20). Hypocotyl lengths of seedlings expressing the serine-substitution mutant CRY2 that are significantly longer than the control seedlings expressing the wild-type CRY2 transgene are indicated *(p≤0.05), **(p≤0.01), or ***(p≤0.001), respectively (Turkey’s LSD Test).