Question

Before opening of stomata, accumulation of which of the following ion is seen?

• A. $P{O}_4$
• B. $K^{+}$
• C. $M{g}^{++}$
• D. $N{a}^{+}$

Answer 1

The correct option is B $K^{+}$

Opening and closure of the stomatal pore is mediated by changes in the turgor pressure of the two guard cells. The turgor pressure of guard cells is controlled by movements of large quantities of ions and sugars into and out of the guard cells. Accumulation of $K^{+}$ ions occurs in gaurds cells before opening stomata. Guard cells have cell walls of varying thickness causing them to bend outward when they are turgid, which causes stomata to open.