Figure 6.

Dependence of IAA-induced protoplast swelling on external K⁺ and Cl^–. Protoplasts were washed with and suspended in a K⁺-free (A and B) or a Cl^–-free (C and D) medium and incubated as described for Figure 1. Time zero corresponded to 30 min after the onset of incubation. At the first vertical dashed line, IAA was applied to the bathing medium to the concentration of 10^–6.5 m (A and C) or 10^–5.0 m (B and D). Immediately after obtaining protoplast images at 100 min, the protoplasts were washed with and suspended in the standard medium. At 110 min (the second vertical line), IAA was applied again to the same concentration. The means obtained from 32 to 40 protoplasts (two experiments) are shown.