Different strategies in higher plants in mobilization and uptake of iron

Summary

This review identifies and characterises two fundamentally different iron-deficiency response strategies in higher plants. Strategy I, present in dicots and non-grass monocots, involves enhanced reductase activity and rhizosphere acidification to solubilise iron. Strategy II, unique to grasses, relies on the release of phytosiderophores (chelating amino acids) to mobilise and uptake iron, and proves more efficient under high pH conditions where Strategy I is inhibited.

Regional applicability

The findings are directly relevant to UK agriculture, particularly for cereal production (barley, wheat, maize) which employ Strategy II. Understanding these mechanisms informs management of iron deficiency chlorosis in calcareous soils common in parts of the United Kingdom, and may guide crop selection and breeding for improved iron acquisition on alkaline soils.

Key measures

Plasma membrane reductase activity, Fe(III) reduction rates, H+ extrusion rates, rhizosphere pH, phytosiderophore release, iron uptake rates, resistance to lime chlorosis

Outcomes reported

The study describes two distinct physiological strategies that higher plants employ to mobilise and uptake iron from soils with low iron availability. Strategy I (dicots and most monocots) relies on plasma membrane reductase activity and rhizosphere acidification, whilst Strategy II (grasses) uses phytosiderophore release to complex iron.

Topic tags