Fluorescence increase.

<p>Increases in chlorophyll fluorescence after the addition of NADPH (0.25 mM) 30 s into the run and ferredoxin (5 μM) 60 s into the run, under weak measuring light (1.0 μmol·m^-2·s^-1) in thylakoid membranes (50 μg Chl·mL^-1) isolated from recently detached leaves of <i>Hibiscus rosa-sinensis</i> plants after exposure to two photoperiods (18 h, 500 μmol·m^-2·s^-1 PPFD), with different temperatures maintained in the stem and in the root (°C stem/°C root): 24°C/24°C (control); 10°C/10°C (chilled plant) and 10°C/24°C (chilled stem). Each photoperiod was followed by a 6 h night-period, maintaining the same temperatures as in the photoperiod. Additionally, thylakoid suspensions were incubated with antimycin A (2 μM) for 2 min prior to the measurements. The figure shows typical curves and the histograms of the means ± SE from four separate plants for each treatment, with duplicate measurements in each plant. Significant differences are indicated by an asterisk (ANOVA, <i>p</i><0.05).