The multiple facets of root iron reduction
Journal
Journal of Experimental Botany
Journal Volume
68
Journal Volume
68
Journal Issue
18
Journal Issue
18
Pages
5021
Start Page
5021
End Page
5027
ISSN
00220957
Date Issued
2017-08-15
Author(s)
Schmidt, Wolfgang
Abstract
The biological significance of iron (Fe) is based on its propensity to oscillate between the ferric and ferrous forms, a transition that also affects its phyto-availability in soils. With the exception of grasses, Fe 3+ is unavailable to plants. Most angiosperms employ a reduction-based Fe uptake mechanism, which relies on enzymatic reduction of ferric iron as an obligatory, rate-limiting step prior to uptake. This system functions optimally in acidic soils. Calcicole plants are, however, exposed to environments that are alkaline and/or have suboptimal availability of phosphorous, conditions under which the enzymatic reduction mechanism ceases to work effectively. We propose that auxiliary, non-enzymatic Fe reduction can be of critical importance for conferring fitness to plants thriving in alkaline soils with low bioavailability of Fe and/or phosphorus.
Subjects
Calcicole plants
coumarins
iron
phosphate
plant nutrition
redox processes
Publisher
Oxford University Press
Type
journal article