What are the specialised features of the Guard Cell?
They can become flaccid or turgid depending on whether the plant is ‘stressed’ or not. If the plant is stressed e.g. there is a high temperature, it produces abscisic acid which the membrane of guard cells have receptors for. The ABA (abscisic acid) binds to the receptors which inhibits the proton pump of the guard cell. No H+ ions can be pumped out and no K+ ions can be pumped in so no water enters the guard cell so they become flaccid, closing the pore so no water can be lost via transpiration.
