Effects of iron deficiency on iron superoxide dismutase expression in Nicotiana tabacum

Abstract

Some dicotyledonous species, including Nicotiana tabacum, have four isozymic forms of superoxide dismutase (SOD, EC 1.15.1.1) one of which, FeSOD, contains iron at its active site. Here we analyze the effects of iron deficiency on the expression of the nuclear gene sodB that encodes FeSOD. We show that in iron-deficient plants the level of active enzyme as well as the apoprotein is reduced. This decrease is a result of a lower sodB transcript level. iron-regulated transcriptional and post-transcriptional control of sodB is discussed.