Fig. 6. Response to long (inductive) photoperiods in wild-type seedlings and phyA, cry1 and cry2 single, double and triple mutant combinations. The seedlings were grown under short photoperiods for 21 days, transferred to long photoperiods for 5 days and returned to short days for the rest of the cycle. Control seedlings remained under short days. Data are means and s.e.m. of 7 plants.