Effects of mutations and of ionophore on chlororespiration in Chlamydomonas reinhardtii

It is shown that electron‐transport elements of the photosynthetic chain located between plastoquinone and photosystem I centers are not involved in oxidation of plastoquinone in the chlororespiratory pathway. The ionophore dicyclohexyl‐18‐crown‐6 is shown to induce a reduction of the plastoquinone pool in the dark. This is interpreted as indicating the existence of a coupling site in the chlororespiratory pathway between NAD(P)H and plastoquinone.