Figure 2.

Hyperpolarization-activated calcium currents at the tip of growing root hairs. (A-–E) Whole-cell patch-clamp, with voltage-clamp protocol shown above current traces. (A-–C) K⁺-containing solutions. Free internal Ca²⁺ concentration was 520 nM. (B) Mean (±SEM) I–V curve of total current (n = 6). (C) Evidence for a Ca²⁺ component in the inward current by tail current analysis; the arrow marks current reversal. (D and E) Extraction of the Ca²⁺ component. Similar experiments to A and C, but with KCl and K-glutamate removed from solutions.