Question

Which of the following does not happen during stomatal opening?

• A. Accumulation of $K^{+}$ ion in guard cell
• B. Increased TP of guard cell
• C. Increased thickening of inner wall of guard cell
• D. Decrease in pH of guard cell

Answer 1

Answer: (C)

The immediate cause of the opening or closing of stomata is a change in the turgidity of the guard cells. During opening, pH of the guard cell decreases, $PEP$ case becomes functional, $PEP$ forms malic acid which dissociates into H⁺ and malate ion and K⁺ -H⁺ pump causes accumulation of K⁺ in guards cell, increasing its turgor pressure.