Iron superoxide dismutase protects against chilling damage in the cyanobacterium synechococcus species PCC7942.

A strain of Synechococcus sp. PCC7942 lacking functional Fe superoxide dismutase (SOD), designated sodB-, was characterized by its growth rate, photosynthetic pigments, inhibition of photosynthetic electron transport activity, and total SOD activity at 0 degrees C, 10 degrees C, 17 degrees C, and 27 degrees C in moderate light. At 27 degrees C, the sodB- and wild-type strains had similar growth rates, chlorophyll and carotenoid contents, and cyclic photosynthetic electron transport activity.