Effect of Uncouplers on Photo-reactivation of Tris(pH 8.8) and 2,6-Dichlorophenol Indophenol-treated Chloroplasts

The oxygen-evolving activity of chloroplasts was lost by Tris(pH8.8)-washing and restored by 2,6-dichlorophenol indophenol treatmentand light exposure. One function of light was the generationof a high-energy state (pH) in chloroplasts, because the additionof uncouplers such as carbonylcyanide-m-chlorophenylhydrazone,atebrin, NH₄Cl, gramicidin J(S), valinomycin, A23187 GenBank] and tetracaineinhibited restoration of the oxygen-evolving activity. The generationof a high-energy state in these chloroplasts was proven by thelight-induced H⁺-incorporation and uncoupler-stimulated electrontransport of the Mehler reaction type. (Received February 15, 1981; Accepted May 12, 1982)