Vd exudate preparation induces [Ca2+]
elevation in A. thaliana seedlings expressing cytosolic aequorin. (A) Roots of 21-day old pMAQ2 in Col-0 seedlings were dissected and incubated overnight in 7.5 μM coelenterezine. The roots were challenged with 50 μl of the Vd preparations. [Ca2+]cyt level was calculated from the relative light unit (RLU) at 5's integration time for 10 min. The arrow indicates the time (60 s) of addition of the stimuli/PBS buffer. For all experiments, 10 mM phosphate buffer (PBS, pH 7.0) was used as control and gave background readings. All curves and values represent average of five independent experiments with eight replications in each experiment. (B) Vd exudate preparation does not induce [Ca2+]cyt elevation in the cycam1 mutant, but induces [Ca2+]cyt elevation in pMAQ2 lines in the glr2.4, glr2.5 and glr3.3 background.