Question

How temperature, pH and mechanical shock affect stomatal movement?

Answer 1

Turgor pressure of guard cells controls the stomatal opening and closing. Stomata open when guard cells are fully turgid and closes when they are flaccid. Tugor pressure of guards cells in turn is regulated by vacuole of guard cells. Turgidity of guard cells drops when their vacuole loses water and vice versa. There are different factors that can lead to change in turgor pressure of guard cells such as s temperature, pH, water stress, light, etc.
pH: Rise in pH of guard cells causes the opening of stomata.
Temperature: Rise in temperature induces stomatal opening while fall in temperature causes closure.
Mechanical shock: Mechanical shock treatment leads to stomatal closure.