Consequences of iron deficiency on photosynthetic and respiratory electron transport in blue-green algae.

Growth of Aphanocapsa in low iron media resulted in a decrease of the endogenous iron pool. Below a critical concentration photosynthetic electron transfer was specifically depressed. This was caused by a strong inhibition of the synthesis of cytochromes b-559 of PSII, cytochromes b-563, f-557, and the 'Rieske' Fe-S center of the cytochrome complex and especially the Fe-S centers of PSI. The influence of iron limitation on respiration and chlorphyll formation was negligible.