Genetic evidence that induction of root Fe(III) chelate reductase activity is necessary for iron uptake under iron deficiency+

Chloroplast Fe(III) chelate reductase activity is essential for seedling viability under iron limiting conditions.

Photosynthesis, heme biosynthesis, and Fe-S cluster assembly all take place in the chloroplast, and all require iron. Reduction of iron via a membrane-bound Fe(III) chelate reductase is required before iron transport across membranes in a variety of systems, but to date there has been no definitive genetic proof that chloroplasts have such a reduction system. Here we report that one of the eigh...

Nitric oxide acts downstream of auxin to trigger root ferric-chelate reductase activity in response to iron deficiency in Arabidopsis.

In response to iron (Fe) deficiency, dicots employ a reduction-based mechanism by inducing ferric-chelate reductase (FCR) at the root plasma membrane to enhance Fe uptake. However, the signal pathway leading to FCR induction is still unclear. Here, we found that the Fe-deficiency-induced increase of auxin and nitric oxide (NO) levels in wild-type Arabidopsis (Arabidopsis thaliana) was accompani...

Characterization of FRO1, a pea ferric-chelate reductase involved in root iron acquisition.

To acquire iron, many plant species reduce soil Fe(III) to Fe(II) by Fe(III)-chelate reductases embedded in the plasma membrane of root epidermal cells. The reduced product is then taken up by Fe(II) transporter proteins. These activities are induced under Fe deficiency. We describe here the FRO1 gene from pea (Pisum sativum), which encodes an Fe(III)-chelate reductase. Consistent with this pro...

[Mutational reconstructed ferric chelate reductase confers enhanced tolerance in rice to iron deficiency in calcareous soil].

Iron (Fe) deficiency is a worldwide agricultural problem on calcareous soils with low-Fe availability due to high soil pH. Rice plants use a well documented phytosiderophore-based system (Strategy II) to take up Fe from the soil and also possess a direct Fe2+ transport system. Rice plants are extremely susceptible to low-Fe supply, however, because of low phytosiderophore secretion and low Fe3+...

Effects of Rhizobacteria on iron uptake and root iron plaque formation in lowland rice under conditions of iron toxicity