Constraints to Synergistic Fe Mobilization from Calcareous Soil by a Phytosiderophore and a Reductant

Author(s)
Stephan Krämer, Walter Schenkeveld
Abstract

Synergistic effects between ligand- and reductant-based Fe acquisition strategies can enhance the mobilization of Fe, but also of competing metals from soil. For phytosiderophores, this may alter the time and concentration window of Fe uptake during which plants can benefit from elevated Fe concentrations. We examined how the size of this window is affected by the ligand and reductant concentration and by non-simultaneous addition. To this end, a series of kinetic batch experiments was conducted with a calcareous clay soil to which the phytosiderophore 2′-deoxymugineic acid (DMA) and the reductant ascorbate were added at various concentrations, either simultaneously or with a one- or two-day lag time. Both simultaneous and non-simultaneous addition of the reductant and the phytosiderophore induced synergistic Fe mobilization. Furthermore, initial Fe mobilization rates increased with increasing reductant and phytosiderophore concentrations. However, the duration of the synergistic effect and the window of Fe uptake decreased with increasing reductant concentration due to enhanced competitive mobilization of other metals. Rate laws accurately describing synergistic mobilization of Fe and other metals from soil were parameterized. Synergistic Fe mobilization may be vital for the survival of plants and microorganisms in soils of low Fe availability. However, in order to optimally benefit from these synergistic effects, exudation of ligands and reductants in the rhizosphere need to be carefully matched.

Organisation(s)
Journal
Soil Systems
Volume
2
Pages
1-22
No. of pages
22
ISSN
2571-8789
DOI
https://doi.org/10.3390/soilsystems2040067
Publication date
12-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
105906 Environmental geosciences, 401902 Soil science
Keywords
ASJC Scopus subject areas
Earth-Surface Processes, Soil Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/6ed94c8e-25c2-47be-9435-53aba3f11380