Fig. 1. Short- and long-term effects of temperature and ABA on [Ca²⁺]_i in A. polypoides cells. FURA 2-loaded cells were incubated at 24°C in SW without (•) or with 4 mM EGTA () in a thermostated microfluorimetric cuvette, under continuous stirring. EGTA-AM loading () or 8-Br-cADPR treatment () of the cells were performed before and after FURA-loading, respectively. The fluorescence emission ratio E340/E380 was acquired every 30 minutes and calibrated to obtain the corresponding [Ca²⁺]_i; each point is the mean of four values. The double bars indicate interruptions in the x- and y-axis. Inset: trace showing the increase in [Ca²⁺]_i as continuously recorded after addition of 50 nM ABA at a constant temperature of 16°C. Traces are from one of five comparable experiments, performed on different animals and giving similar results.