Figure 7.

Changes of Calcium Channel Activity in Guard Cells of ATGPX3-Deficient Mutant and Overexpression Plants.

(A) ABA (50 μM) failed to activate Ca²⁺ channel currents in the atgpx3-1 mutant but greatly increased Ca²⁺ channel currents of guard cells in ATGPX3 overexpression transgenic lines.

(B) Effects of ATGPX3 mutation and overexpression on calcium channel activity at –150 mV (n = 35 [wild type], 28 [wild type + ABA], 13 [atgpx3-1 + ABA], 7 [ATGPX3 overexpression + ABA], and 10 [complementation line + ABA]). Error bars indicate sd.

(C) Single-channel current of calcium from guard cells of an ATGPX3 overexpression plant.

(D) Dependence of channel open probability on pressure in the pipette. The open probability gradually increased with negative pressure. Values are means ± sd (n = 3 or 4).