Geochemical Aspects of Phytosiderophore-Promoted Iron Acquisition by Plants
- Author(s)
- David Crowley, Stephan Krämer
- Abstract
Iron is an essential trace nutrient for all plants. The acquisition of iron is limited by low solubilities and slow dissolution rates of iron-bearing minerals in many soils. Therefore, iron limitation can be an important nutritional disorder in crop plants, leading to decreased yields or significant costs for iron fertilization. However, some species among the group of graminaceous plants (including wheat and barley) exhibit a rather low susceptibility to iron deficiency. These species respond to iron-limiting conditions by the exudation of ligands with a high affinity and specificity for iron complexation, the so-called phytosiderophores. Soluble iron-phytosiderophore complexes are recognized and transported across the root plasma membrane by specific transport proteins. This chapter focuses on geochemical aspects of this so-called "strategy II" iron acquisition mechanism. The coordination chemistry of phytosiderophores and their iron complexes in the soil solution are discussed and compared to other organic ligands including low-molecular weight organic acids and microbial siderophores. The properties of iron complexes and iron-bearing minerals in the rhizosphere are discussed and compared with regard to their potential as sources of plant available iron. An important focus of this chapter is the elucidation of the thermodynamics, mechanisms, and rates of iron acquisition from these sources by phytosiderophores. Thus, we hope to contribute to the understanding of iron acquisition by strategy II plants in particular and of iron cycling in the rhizosphere in general. © 2006, Elsevier Inc. © 2006 Elsevier Inc. All rights reserved.
- Organisation(s)
- External organisation(s)
- University of California, Riverside
- Journal
- Advances in Agronomy
- Volume
- 91
- Pages
- 1-46
- No. of pages
- 46
- ISSN
- 0065-2113
- Publication date
- 2006
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 106015 Geobotany
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/bbd89a9d-a756-48d6-9491-4a5d00209af3