Acclimation to environmentally relevant Mn concentrations rescues a cyanobacterium from the detrimental effects of iron limitation.
The functions of micronutrient transition metals in photosynthetic organisms are interconnected. So are the effects of their limitation. Here we present evidence for the effects of Mn limitation on Fe limitation responses in the cyanobacterium Synechocystis sp. PCC 6803. Low Mn acclimated cells were able to detect and respond to iron insufficiency by inducing specific Fe transporters. However, they did not bleach, lose additional photosystem I activity and did not induce isiA transcription. Induction of the isiAB operon is a hallmark of iron limitation, and the isiA protein is considered to be central to the acclimation of the photosynthetic apparatus. Our results suggest that acclimation to environmentally relevant Mn concentrations that much lower than those used in laboratory experiments reduces the detrimental effects of iron limitation and modifies iron stress responses.
Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
Eitan
E
Salomon
Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
Nir
N
Keren
D000064:Acclimatization / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism*; D000090463:Iron Deficiencies; D045342:Light-Harvesting Protein Complexes / Q000096:biosynthesis / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology; D045331:Photosystem I Protein Complex / Q000235:genetics; D046939:Synechocystis / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; C076726:chlorophyll A binding protein CP43, Cyanobacteria; D008345:Manganese