Expression of Ferritins ZmFer1 and ZmFer2 Genes in Shoots and Roots of S-Deprived Young Maize Plants

Abstract

A perturbation of the iron levels is observed in maize, as an early effect of sulfur deprivation. Ferritins (ferroxidase, EC 1.16.3.1), readily interact with Fe(II) inducing its oxidation and its deposition as an insoluble mineral iron core into a central enzyme cavity. Fourteen-day-old maize seedlings were subject to sulfur (−S) deprivation for 6 days, in a hydroponic culture, and the expression of ZmFer1 and ZmFer2 ferritin genes, in shoots and roots, was monitored at the indicated time intervals by means of real time RT-PCR. The response of the individual expression levels of the ferritin genes differed under sulfur deprivation. In control plants, the range of the relative expression ratio of ZmFer1 gene was higher in the shoots than that of the roots. The same was observed for the expression of the ZmFer2 gene. The relative expression of ZmFer1 was higher compared with that of ZmFer2 gene in both shoots and roots. S deprivation caused a decrease in ZmFer1 gene expression and an increase in ZmFer2. The response of both ferritin genes takes place first in the root. ZmFer1 gene expression apparently decreased because there was not an iron redundancy for storage. ZmFer2 gene expression increased in response to sulfur stress and/or in coordination to antioxidant action, which takes place under the aforementioned experimental conditions.