The Relation between Photophosphorylation and Delayed Light Emission in Chloroplasts

One millisecond delayed light emission has been studied in isolated coupled lettuce (Lactuca sativa var. romaine) chloroplasts. Delayed light emission was increased upon addition of ferricyanide or 2,3,5,6-tetramethyl-p-phenylene diamine. In the presence of ferricyanide, the magnitude of the signal was increased by the addition of ADP (in the absence of orthophosphate), ATP, DI0-9, or phlorizin. The signal was also increased by the addition of NaCl and by the addition of NH₄Cl in the presence of a high NaCl concentration. The signal of delayed light emission was decreased by the addition of gramicidin, valinomycin, and by the addition of NH₄Cl in the presence of a low NaCl concentration.