Diurnal fluctuation in the composition of chlorophyll a/b light harvesting antenna of photosystem II in young wheat leaves

We investigated the diurnal fluctuation in the composition of the light harvesting chlorophyll a/b antenna of photosystem II in young wheat (Triticum aestivum) leaves grown under periodic day/night irradiation. By means of gel electrophoresis of the polypeptides of thylakoid membranes, we determined the amount of 25 kDa and 27 kDa polypeptides, which are the main components of the peripheral and inner antenna subpopulations, respectively. Our data show a preferential fluctuation in the amount of the 25 kDa protein relative to the 27 kDa polypeptide, in parallel to the fluctuation in the amount of chlorophyll a/b antenna of photosystem II, which suggests that the peripheral antenna plays a role in the diurnal adjustment of the antenna size.