Question

How do changes in TP help in the opening and closing mechanism of stomata?

Answer 1

Stomata is the minute opening present in the leaves of the plants through which the water is losses as the vapor by the process of transpiration. This pore is not always in open conditions. It may open or close depending on the guard cells surrounding the stomata.

Complete answer:
Transpiration is the process by which the water is lost through the stomatal openings. This opening and the closing of the stomata is controlled by the guard cells surrounding the pores of the stomata in the leaves. Transport of potassium in the guard cells maintains the turgor pressure in the guard cells, this helps in the opening or the closing of the stomata.

(1) Opening of stomata
Guard cells are full of potassium ions and in order to balance it, water from the nearby guard cells enter into these guard cells. As the water enters, the guard cell becomes bulge and swollen. This increases the turgor pressure and makes the stomatal pores open.

(2) Closing of stomata
This occurs when the water from the guard cell moves out and the turgor pressure gets reduced. At this time guard cells become flaccid and the pores of the stomata closes. Transport of the potassium ion is responsible for the changes in the stomata opening and closing mechanism

Note: Opening of stomata mainly occurs at the presence of sunlight and when the photosynthesis takes place. And the closing of the stomata is the opposite of the opening phenomenon. And the closing occurs at the time of night where there is absence of sunlight.