Le Labex Dynamo
2019 Nawrocki et al.
Chlororespiration controls growth Under intermittent light.
Nawrocki et al., Plant Physiology 2019
Whereas photosynthetic function under steady-state light conditions has been well charactarised, little is known about its changes that occur in response to light fluctuations. Chlororespiration, a simplified respiratory chain, is widespread across all photosynthetic lineages, but its role remains elusive. Here, we show that chlororespiration plays a crucial role in intermittent might conditions in the green alga Chamydomonas reinhardtii. Chlororespiration, which is localized in thylakoid membranes together with the photosynthetic electron transfer chain, involves plastoquinone (PQ) reduction, and plastoquinol (PQH2) oxidase. We demonstrate that the hampered growth results from a major change in the kinetics of redox relaxation of the photosynyhetic electron transfer chain during the dark periods. This change, in turn, has a dramatic effect on the physiology of the photosynthesis during the light periods. This change, in turn, has a dramatic effect on the physiology of photosynthesis during the light periods, notably stimulatiing cyclic electron flow at the expense of the linear electron flow.
Publié le : 16/01/2019