Geochemical Processes Constraining Iron Uptake in Strategy II Fe Acquisition
- Author(s)
- Walter Schenkeveld, Yvonne Schindlegger, Eva Oburger, Markus Puschenreiter, Stephan Hann, Stephan Krämer
- Abstract
Phytosiderophores (PS) are natural chelating agents, exuded by graminaceous plants (grasses) for the purpose of Fe acquisition (Strategy II). They can form soluble Fe complexes with soil-Fe that can be readily taken up. PS are exuded in a diurnal pulse release, and with the start of PS release a "window of iron uptake" opens. In the present study we examined how this window is constrained in time and concentration by biogeochemical processes. For this purpose, a series of interaction experiments was done with a calcareous clay soil and the phytosiderophore 2′-deoxymugineic acid (DMA), in which metal and DMA speciation were examined as a function of time and DMA concentration. Various kinetically and thermodynamically controlled processes affected the size of the window of Fe uptake. Adsorption lowered, but did not prevent Fe mobilization by DMA. Microbial activity depleted DMA from solution, but not on time scales jeopardizing Strategy II Fe acquisition. Complexation of competing metals played an important role in constraining the window of Fe uptake, particularly at environmentally relevant PS concentrations. Our study provides a conceptual model that takes into account the chemical kinetics involved with PS-mediated Fe acquisition. The model can help to explain how success or failure of PS-mediated Fe acquisition depends on environmental conditions.
- Organisation(s)
- External organisation(s)
- University of Natural Resources and Life Sciences, acib – Austrian Centre of Industrial Biotechnology
- Journal
- Environmental Science & Technology
- Volume
- 48
- Pages
- 12662-12670
- No. of pages
- 9
- ISSN
- 0013-936X
- DOI
- https://doi.org/10.1021/es5031728
- Publication date
- 2014
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105906 Environmental geosciences
- ASJC Scopus subject areas
- General Chemistry, Environmental Chemistry
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/983016cb-bfce-4304-ac03-841a2ddeda64