Ferritin synthesis in response to iron in the Fe-inefficient maize mutant ys3

It was reported that in Fe-inefficient Zea mays L. mutant yellow stripe 1 (ys1), unlike other plant species, the regulation of ferritin accumulation upon iron overload is controlled at the post-transcriptional level. We conducted similar experiments with another Fe-inefficient maize mutant, yellow stripe 3 (ys3), affected in a different step of iron acquisition. Uptake of iron by roots was followed in leaves of both mutant and wild type plants using ferritin mRNA and protein accumulation. We can thus demonstrate that in maize the presence of iron controls ferritin synthesis at the transcriptional level. Because of the difference in the response of ys1 and ys3, we also postulate the presence of a second factor acting translationally, related to the level of ferrated phytosiderophore.