Photoinactivation of Photosystem II in Prochlorococcus and Synechococcus

摘要: The marine picocyanobacteria Synechococcus and Prochlorococcus numerically dominate open ocean phytoplankton. Although evolutionarily related they are ecologically distinct, with different strategies to harvest, manage exploit light. We grew representative strains of tracked their susceptibility photoinactivation Photosystem II under a range light levels. As expected blue provoked more rapid than did an equivalent level red previous growth altered the Synechococcus, but not Prochlorococcus, this photoinactivation. resolved simple linear pattern when we expressed yield on basis photons delivered photochemistry, plotted versus excitation pressure upon II, balance between downstream metabolism. A high increases generation reactive oxygen species, thus II. Blue photons, however, retained higher baseline across wide pressures. Our experiments uncovered relative influences direct by which dominates low moderate light, as side effect species pressure. enjoyed positive metabolic return repair or synthesis levels tested. In contrast only up 400 μmol m-2 s-1. These differential cost-benefits probably underlie distinct photoacclimation species.