The effects of light and CO2 on the electrophysiological characteristics of guard cells in the intact leaf and isolated epidermis have been investigated. Fast hyperpolarization of guard cell apoplastic PD in the intact leaf was recorded reaching up to

The effects of different light quality on the change of membrane potential difference (PD) of the guard cell in the intact leaf have been investigated. The mombrane PD was about -5.5 mV by white light of 600 μmoles m-2 s-1. The mean PD of ch

3-weeks old Commelina was transferred to and grown in Hoagland solution (± 100 μM Cd2+, 100 μM Cd2+ ＋ 100μM Ca2+, 100 μM Cd2+ ＋ 200 μM EGTA) for two weeks and then a number of physiological activities

The effects of light and darkness on stomatal aperture and guard cell apoplastic pH in the intact leaf and in the isolated epidermal strips of Commelina communis have been investigated. Stomata in the intact leaf opened wide in the light. In contrast, sto

Many researchers have been studied with guard cell protoplasts and detached epidermis as they think that properly stabilized protoplasts and detached epidermis retain many of the properties of intact guard cells. However, some studies have shown that stom

The effect of CO2 on the opening of stomata in the intact leaf of Commelina communis has been investigated. Full opening of stomatal apertures(around 18 μm) was achieved in the intact leaf by addition of CO2(900 μmol mol-1). At 90 minutes, the stomatal apertures of leaves treated with CO2 free air were reduced. In contrast, stomata opened most widely with the treatment of CO2 air at 90 minutes. The effects of light, CO2 air and CO2 free air on the change of membrane potential difference(PD) were measured. Fast hyperpolarization of guard cell membrane PD was recorded reaching up to -12 mV in response to light. If CO2 free air was given firstly, there was no response. When light was given after CO2 free air, the light effect was very clear. At the onset of CO2 air, the PD showed a dramatic hyperpolarization to about -25 mV. Changes in the pH of apoplast in intact leaves in response to CO2 air were observed. CO2 air caused a change of 0.4 pH unit. Therefore, it can be hypothesized that CO2 flowing could stimulate proton efflux which is a necessary precursor of stomatal opening.