Co-exudation of reductants and ligands also has been observed under Fe deficient soil environments. In the presence of both a reductant and a ligand, synergistic Fe mobilizations from Fe-oxide have been shown in single Fe(III) (hydr)oxide minerals and calcareous soil. One of the proposed hypotheses of synergistic Fe mobilization is reductant-induced surface labilization catalyzes ligand-controlled Fe-oxide dissolution processes.
Recently it has been observed Fe-deficient Arabidopsis plants exudate coumarin-types compounds as root exudates which can reduce Fe(III) (low solubility) to Fe(II) (high solubility) as well as chelate both Fe(II) and Fe(III). However, identifications of coumarin-type root exudates, functional groups of the compounds regarding Fe reduction and chelation, and chemical mechanisms of Fe-oxide dissolution processes by coumarins have not been elucidated so far.
The goals of this project are identifying of coumarin-type compounds with specific Fe-related functions such as the chelation and/or reduction, and elucidating Fe-oxide dissolution mechanisms by coumarins in particular with regards to synergism between reductive and ligand-controlled dissolution.
This research is funded by the Austrian Science Fund (FWF, Grant No.: I2865-N34).