FIGURE 4.

Relaxation of flash induced chlorophyll fluorescence in heat preconditioned (42 °C, 3 h) WT (circles) and Q16R (triangles) cells. Fluorescence excitation was achieved with a single turnover saturating flash at t = 1 ms. Subsequent fluorescence relaxation was measured in the absence of electron transport inhibitors (A) and in the presence of 10 μm (3-(3,4-dichlorophenyl)-1, 1-dimethylurea (DCMU) (B). The curves shown were normalized to the same initial amplitude and corrected according to Joliot and Joliot (24) to consider nonlinear relationships of fluorescence yield and Q^–_A concentration.