Chlororespiration

The term 'chlororespiration' is used to describe the activity of a putative respiratory electron transfer chain within the thylakoid membrane of chloroplasts and was originally proposed by Bennoun in 1982 to explain effects on the redox state of the plastoquinone pool in green algae in the absence of photosynthetic electron transfer. In his original model, Bennoun suggested that the plastoquinone pool could be reduced through the action of a NAD(P)H dehydrogenase and could be oxidized by oxygen at an oxidase. At the same time an electrochemical gradient would be generated across the thylakoid membrane. This review describes the current status of the chlororespiration model in light of the recent discoveries of novel respiratory components within the chloroplast thylakoid membrane.