The use of light‐induced absorbance changes at 820 nm to monitor the oxidation state of P‐700 in leaves

Abstract The use of the light‐induced absorbance change at 820 nm (ΔA 820) to monitor the oxidation and reduction of P‐700 in irradiated leaves is examined. Results obtained from leaves irradiated with a range of wavelengths of light, poisoned with DCMU, or lacking PS I, are consistent with the proposition that the light‐induced ΔA 820 can be used to monitor P‐700 oxidation in leaves.