Subcellular localization of iron and manganese superoxide dismutase in Chlamydomonas reinhardtii (Chlorophyceae)

Subcellular localization of superoxide dismutase (SOD) isozymes in Chlamydo monas reinhardtii Dangeard was investigated. From both biochemical and immu nological studies, Fe- containing superoxide dismutase (Fe SOD) was localiz ed in the chloroplast, and the major Mn-containing SOD (Mn SOD) was localiz ed in the mitochondria, We isolated cDNA clones, Sod1, and Sod2, which enco de Mn SOD and Fe SOD, respectively. Genomic DNA hybridization with these SO D clones demonstrated that there are two additional sequences closely relat ed to Sod1, The transcriptional levels of both genes were compared in light - and dark-gown cells, Mn SOD was higher in heterotrophically grown cells, whereas the accumulation of Fe SOD transcripts was higher under phototrophi c condition.