Question

For keeping stomata open, besides $K^{+}$ ions the guard cells require a constant supply of

• A. ABA
• B. ATP
• C. Organic acids
• D. Protons

Answer 1

The correct option is B ATP

Guard cells help to regulate the rate of transpiration by opening and closing the stomata. When the guard cells are turgid/swollen, then this turgidity is caused by the accumulation of K ions in guard cells. As K ion level increases, the water potential of guard cells drops and water enters the guard cells and for diffusion of water and activity of guard cells, it requires energy which is utilized from ATP form of energy. Thus this requires a constant supply of ATP.

So the correct answer is 'ATP'.