Figure 5

Imposed intracellular calcium transients in pGC1::YC3.60 expressing guard cells and spontaneous calcium transients occur in guard cells of intact pGC1::YC3.60 transgenic plants. A. Fluorescence image of leaf epidermis of pGC1::YC3.60 transgenic plant. Note the surrounding epidermal cells were not fluorescent. B. The 6 guard cells in panel A all produced intracellular calcium transients in response to imposed calcium oscillations. The arrows mark the switch point from the depolarizing buffer to the Ca²⁺-containing hyperpolarizing buffer (see Methods). C. A pseudo-colored ratiometric image of a leaf from an intact Col plants transformed with pGC1::YC3.60. The orange-yellow color indicates higher [Ca²⁺] and the blue color indicates lower [Ca²⁺]. Spontaneous calcium transients occurred in leaves of intact Arabidopsis plants (movies are shown as additional files 10 and 11). D. A time course (25 minutes) of the emission ratios of the two guard cells marked by an arrow in C shows that spontaneous calcium transients occur in intact Arabidopsis plants. The ratio was calculated for individual cells by dividing the YFP emission intensity by the CFP emission intensity.