Photosystem I-initiated postillumination CO2 burst in a cyanobacterium,Anabaena variabilis

In Anabaena variabilis, a postillumination CO₂ burst originating from a pool of HCO₃^? is described here. This burst is insensitive to the electron-transport inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, but is abolished by carbonyl cyanide p-trifluoromethoxyphenylhydrazone and N,N′-dicyclohexylcarbodiimide (inhibitors of photophosphorylation). The action spectrum for the burst shows that only Photosystem I is involved.