Which ion plays the most prominent role in the opening and closing of stomata?

Question

Quizplus · Accepted Answer

K⁺ ions play a crucial role in the opening and closing of stomata. When K⁺ ions accumulate in the guard cells, water follows by osmosis, causing the guard cells to swell and the stomata to open. Conversely, when K⁺ ions are pumped out of the guard cells, water follows by osmosis, causing the guard cells to shrink and the stomata to close.

Which Ion Plays the Most Prominent Role in the Opening