Two iron-responsive promoter elements control expression of FOX1 in Chlamydomonas reinhardtii

FOX1 encodes an iron deficiency-induced ferroxidase involved in a high-affinity iron uptake system. Mutagenesis analysis of the FOX1 promoter identified two separate iron-responsive elements, FeRE1 (CACACG) and FeRE2 (CACGCG), between positions -87 and -82 and between positions -65 and -60, respectively, and both are needed for induced FOX1 expression under conditions of iron deficiency.