Fig. 1. The los2 mutation impairs cold-induced luminescence expression. (A) Luminescence images of wild-type and los2 plants. (a) Wild-type and los2 seedlings used for cold or ABA treatment. (b and c) Luminescence of wild-type and los2 seedlings after low temperature (0°C, 24 h) or ABA treatment (100 µM ABA, 3 h). (d) Wild-type and los2 seedlings used for NaCl or PEG treatment. (e and f) Luminescence of wild-type and los2 seedlings after NaCl (300 mM NaCl, 5 h) or PEG treatment (30% PEG 6000, 5 h). The color scale on the right shows the luminescence intensity from dark blue (lowest) to white (highest). (B) Luminescence intensity in wild-type and los2 plants under different stresses. Shown are the mean values ± SE from 20 individual seedlings. Stress treatments were as described in (A). (C) Time course of luminescence expression in wild-type and los2 plants during cold treatment. The wild-type and los2 plants on the same agar plate were incubated at 0°C for the indicated time and luminescence images were taken. Shown are the mean values ± SE from 20 individual seedlings.