Figure 3.

Effect of the Ca²⁺ channel blocker LaCl₃ on the H₂O₂-induced [Ca²⁺]_cyt signature [Ca²⁺]_cyt was measured by luminometry as described in “Materials and Methods.” A, Inhibition of the early [Ca²⁺]_cyt peak by LaCl₃. Seven-day-old reconstituted RLD1.1 seedlings were incubated for 1 h in LaCl₃ solution (concentrations indicated in the legend) or water (control) prior to transfer into plastic cuvettes. H₂O₂ (final concentration 10 mm) was added at 5 s. At 120 s, remaining aequorin was discharged. Traces represent the mean of 4 seedlings with error bars indicating se at that time point. B, Effect of LaCl₃ on the late H₂O₂-induced [Ca²⁺]_cyt peak. Seven-day-old reconstituted RLD1.1 seedlings were incubated individually in 0.1 mm LaCl₃ solution or water (control) for 30 min inside a plastic cuvette. H₂O₂ (final concentration 10 mm) was added at 5 s. At 3,600 s, remaining aequorin was discharged. Traces represent the responses of 3 individual seedlings per treatment.