Fig. 2.

Kinetics of P₇₀₀ and PC oxidation measured in pea leaf submitted to far-red illumination. K_{i PSI} ≈8.4 × 10 s^-1.(A) Absorption changes were measured at 705 nm. (B) Kinetics of P₇₀₀ oxidation. (B Inset) Kinetics of P₇₀₀⁺ reduction after 20 s of far-red illumination in conditions of curves 1 and 3 in B.(C) Kinetics of PC oxidation. Ordinate is expressed in ΔI/I × 10³. Measurements at 870 and 520 nm (fluorescence) are not shown. Curves 1 and 2. To reach reproducible kinetics, the dark-adapted leaf was submitted to cycles of 20 s of far-red light, 5 min of dark, 20 s of far-red light, and 20 min of dark. Curves 1 and 2 are obtained after 20 and 5 min of dark, respectively. Curve 3, cycles of 10 min of green light, 5 min of dark, and 20 s of far-red light. Dash-dotted line, P⁺_max (see text).