Figure 4.

Hypocotyl elongation and anthocyanin accumulation under multiple far-red-light pulse treatments. Seedlings were irradiated with multiple far-red-light pulses (716-nm DAL interference filters) of 6 μmol m⁻² s⁻¹ for 2.5 min, varying the duration of the dark phases between the light pulses. Hypocotyl length and anthocyanin accumulation were determined after applying the pulse program for 3 d after the induction of germination. A, Relative hypocotyl length for WS, spa1, eid1-3, and eid1-5. The hypocotyl lengths of the dark controls correspond to those shown in Figure 1. B, Relative hypocotyl lengths for WS, Col, and eid1-6. Hypocotyl length of dark controls were 10.0 ± 0.2 mm for Col and 9.1 ± 0.2 mm for eid1-6 (mean ± se). C, Relative anthocyanin contents of WS, spa1, and eid1-5 seedlings. Anthocyanin content was determined spectroscopically after extraction of 50 seedlings. The absolute absorption values obtained for continuous irradiation were 0.091 for WS, 0.094 for spa1, and 0.081 for eid1-5. Error bars represent se.