Searching iron sensors in plants by exploring the link among 2’-OG-dependent dioxygenases, the iron deficiency response and metabolic adjustments occurring under iron deficiency

• Main Authors: GIANPIERO eVIGANI, Piero eMorandini, IRENE eMURGIA
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2013-05-01
• Series: Frontiers in Plant Science
• Subjects: Arabidopsis thaliana; iron deficiency; gene coregulation; iron sensor; HIF (Hypoxia Inducible Factor); 2’OG-dependent dioxygenases
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fpls.2013.00169/full

Knowledge accumulated on the regulation of iron (Fe) homeostasis, its intracellular trafficking and transport across various cellular compartments and organs in plants; storage proteins, transporters and transcription factors involved in Fe metabolism have been analysed in detail in recent years. However, the key sensor(s) of cellular plant Fe status triggering the long-distance shoot-root signalling and leading to the root Fe-deficiency responses is (are) still unknown. Local Fe sensing is also a major task for roots, for adjusting the internal Fe requirements to external Fe availability: how such sensing is achieved and how it leads to metabolic adjustments in case of nutrient shortage, is mostly unknown. Two proteins belonging to the 2′-OG dependent dioxygenases family accumulate several folds in Fe-deficient Arabidopsis roots. Such proteins require Fe(II) as enzymatic cofactor; one of their subgroups, the HIF-P4H (Hypoxia Inducible Factor- Prolyl 4-Hydroxylase), is an effective oxygen sensor in animal cells. We envisage here the possibility that some members of the 2′-OG dioxygenase family may be involved in the Fe-deficiency response and in the metabolic adjustments to Fe deficiency or even in sensing Fe, in plant cells.