Ferreting out the secrets of plant ferritin ‐ A review

Abstract

Ferritin is present in almost all species and was detected in many cells, mainly in tissues not associated with full photosynthetic activity and throughout the plant life cycle. It is quite interesting that phytoferritin from an algal source has not been reported except soms initial short, indirect evidence on its presence in algae (Abadi and Dubois‐Tylski 1974). Unicells of algae, prokaryotic or eukaryotic. may have a great advantage in the study of ferritin synthesis. In such systems we deal with one independent cell without the involvement of any adjacent tissue, and its botanical function resembles the higher ferritin containing plant cell. Ferritin clusters deposited in plastidal stroma are classified into four categories: F‐l, amorphous, close packed particles; F‐2, scattered macromolecules; F‐3, paracrystalline and F‐4, crystalline array. The main functions of plant ferritin are: as an iron storeroom in a nontoxic form, for sequestering the cellular extra lethal iron in a safe buffered form, and the mobilization of iron to requested sites. Aspects of iron and ferritin mobilization in plant vascular tissues have been presented. There are still several open questions concerning the assembly and function of ferritin molecules in plants. It is hoped that future studies will answer some of these questions.

Key words:

• Phytoferritin iron storage
• iron transport protection from iron excess
• apoferritin