Photosynthesis regulation impacts carbon and nitrogen assimilation in the diazotrophic cyanobacterium Anabaena sp. PCC 7120

fixation activity mainly relied on the C supply. Upon diazotrophic conditions, the total photosynthetic electron transport increased, with a modified contribution of different electron pathways. A mutant strain affected in the vehiculation of fixed N between cell types showed that the modulation of photosynthesis depended on the metabolic connection between assimilation pathways. Overall, data showed that the regulation of photosynthetic electron fluxes is a major component of the synergic metabolic relationship between C and N assimilation pathways upon dynamic environmental conditions.