Gibberellic Acid Induces Vacuolar Acidification in Barley Aleurone.

Abstract

The roles of gibberellic acid (GA3) and abscisic acid (ABA) in the regulation of vacuolar pH (pH,) in aleurone cells of barley were investigated using the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF). BCECF accumulated in vacuoles of aleurone cells, but sequestration of the dye did not affect its sensitivity to pH. BCECFloaded aleurone cells retained their ability to respond to both GA3 and ABA. The pH, of freshly isolated aleurone cells is 6.6, but after incubation in GA3, the pH, fel1 to 5.8. The pH, of cells not incubated in hormones or in the presence of ABA showed little orno acidification. The aleurone tonoplast contains both vacuolar ATPase and vacuolar pyrophosphatase, but the levels of pump proteins were not affected by incubation in the presence or absence of hormones. We conclude that GA3 affects the pH, in aleurone cells by altering the activities of tonoplast H+ pumps but not the amounts of pump proteins.

Rapid and orthogonal logic gating with a gibberellin-induced dimerization system

“…Gibberellin is reported to induce acidification in plant cells 37 . To test whether addition of GA 3 -AM induces acidification in mammalian cells, we monitored pH in cells using a Venus fluorescent protein containing one amino acid substitution (H148G) to become sensitive to proton concentration in the environment 38 .…”

Light-induced morphological alteration in anthocyanin-accumulating vacuoles of maize cells

“…However, alterations in vacuolar pH or the association of anthocyanins with co-pigments can also result in changes in the hue of anthocyanin pigmentation [13,14]. To investigate whether light induces a change in the vacuolar pH of BMS cells, we utilized the BCECF-AM fluorescent dye, for which the ratio of fluorescence emission at the dual excitation wavelengths of 490 nm/440 nm can be calibrated to an in vivo generated pH curve [32]. Using this method, we established that the vacuoles of dark and light grown BMS cells were acidic at pH 5.8 and showed no significant pH differences (see Additional file 2: Fig.…”

The transgene pyramiding tobacco with betaine synthesis and heterologous expression of AtNHX1 is more tolerant to salt stress than either of the tobacco lines with betaine synthesis or AtNHX1

“…The pH‐sensitive fluorescent dye 2′,7′‐bis(2‐carboxyethyl)‐5(6)‐carboxy‐fluorescein tetraacetoxymethyl ester (BCECF‐AM, cell‐permeant acetoxymethyl ester derivate of BCECF), purchased from Molecular Probes, was used to measure cytoplasmic and vacuolar pH (Nathalie et al 1996; Swanson and Jones 1996). A 1 m M BCECF‐AM stock solution in anhydrous dimethylsulfoxide was stored at −20°C in the dark (Haugland 2004), and was added to the protoplasts suspension at a final concentration of 2 μ M .…”