Fig. 1.

Blue-light dependency of the cell death response induced in seedlings of the flu mutant. Seedlings of flu were kept under continuous light for 5 days, followed by 15 h of darkness and exposure to white light for 1 h at 100 μmol·m⁻²·s⁻¹ to allow singlet oxygen production. The seedlings were subsequently placed for 23 h in white light at 100 μmol·m⁻²·s⁻¹ (A), in darkness (B), or in red (C) or blue (D) light, both at 10 μmol·m⁻²·s⁻¹. (E and F) Control seedlings that were kept for 24 h under red (E) or blue (F) light at 10 μmol·m⁻²·s⁻¹ without the 1-h white-light treatment.