Figure 8.

Dependence of the protoplast shrinking response to a blue-light pulse on K⁺, Cl⁻, and Ca²⁺ of the bathing medium. The wild-type protoplasts, isolated as described for Figure 1, were washed with and suspended in the modified incubation media listed below (see Fig. 1 for the basic medium composition). The protoplasts were stimulated with a blue-light pulse immediately after time 0, which was 65 min (A and B) or 50 min (C) after the onset of incubation. A, Cl⁻ in the medium was replaced by IDA (14 mm IDA, 10 mm KOH, and 2 mm Ca[OH]₂ were used instead of 10 mm KCl and 2 mm CaCl₂). B, K⁺ in the medium was replaced by TEA⁺ (10 mm TEA-Cl was used instead of 10 mm KCl). C, CaCl₂ in the medium was omitted and 1 mm EGTA was added to the final suspension medium. The protoplasts that were in the volume range from 5 × 10³ to 30 × 10³ μm³ at time 0 were analyzed. The means ± se from 19 or 20 protoplasts are shown. Other details are as described in Figure 3.