13 torthaí
Potassium sensitive microelectrodes have been used to determine the potassium content of individual epidermal cells in intact leaves of C. communis L. Large gradients of potassium across the stomatal complex were observed. When the stomata were open a stepwise decrease in vacuolar potassium content
The membrane electrical characteristics of stomatal guard cells in epidermal strips from Vicia faba L. and Commelina communis L. were explored using conventional electrophysiological methods, but with double-barrelled microelectrodes containing dilute electrolyte solutions. When electrodes were
Abscisic acid (ABA) at a concentration of 100 μm reduced the mean stomatal aperture on isolated epidermis of Commelina communis from 9.5 to 3.1 μm. This closure resulted from a fall in osmotic pressure of the guard cells from 14.1 to 9.8 bars; the osmotic pressure of the subsidiary cells did not
The effects of preillumination were investigated on ion-stimulated stomatal opening of epidermal strips isolated from Commelina communis L. leaves, which are dark-starved 24 hours or more. The rate and the extent of ion-stimulated stomatal openings were increased by preexposure of epidermal strips
A chloride selective micro-electrode has been used to determine vacuolar chloride concentrations in individual cells of the leaf epidermis of Commelina communis. When the stomata were open a gradient in chloride concentration across the stomatal complex was observed with the highest concentration in
The vacuolar pH of individual cells of the epidermis of intact leaves of Commelina communis L. has been determined using pH sensitive microelectrodes. The results show that the pH of the guard cells increases by approximately 0.5 units during stomatal opening. The changes in vacuolar pH mirror the
Effects of fusicoccin alone and together with abscisic acid were observed on the stomatal complex of Commelina communis. The experimental material consisted of isolated epidermal strips incubated in a medium containing the ions required for stomatal opening. Fusicoccin stimulated opening and this
The uptake of glucose and other carbohydrates into the guard cells of Commelina communis L. was found to inhibit the opening of the stomata. The concentration of glucose necessary to achieve about 50% inhibition was of the same order of magnitude as the potassium concentration required for opening;
The effects of anion-channel blockers on light-mediated stomatal opening, on the potassium dependence of stomatal opening, on stomatal responses to abscisic acid (ABA), and on current through slow anion channels in the plasma membrane of guard cells were investigated. The anion-channel blockers
Methyl jasmonate (MJ) and a mixture of G(1), G(2), and G(3) (G-substances) inhibited stomatal opening in abaxial epidermis of Commelina benghalensis and complete closure occurred at 10(-6) molar MJ, or 10(-3) molar G-substances compared to 10(-5) molar abscisic acid (ABA). Proline, even at 10(-3)
BACKGROUND
Many plants with antidiabetic properties probably act in part through their content of fibre, vitamins, bioactive or mineral content
OBJECTIVE
This study investigated the mineral, proximate, phytochemical compositions and hypoglycaemic effect of Commelina africana and Ageratum conyzoides
The concentration of potassium chloride required in the incubation medium to open stomata in isolated epidermal tissues of Commelina communis L. and Vicia faba L. could be lowered from 100 mM to 10 mM if the proton concentration of the ambient solution was increased from pH 5.6 to pH 3.5. This
The pharmacology has been further investigated of the two transport systems mediating potassium (rubidium) (K(+)(Rb(+))) release from the guard cell vacuole, responsible, respectively, for the resting efflux and abscisic acid (ABA)-induced transient stimulation of efflux, and for the transient