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The Caco-2 Cell Bioassay for Measurement of Food Iron Bioavailability
Published on: April 28, 2022
Two MATE proteins play a role in iron efficiency in soybean
Elizabeth E Rogers1, Xiaolei Wu, Gary Stacey
1Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA. elizabeth.rogers@ars.usda.gov
Journal of Plant Physiology
|April 4, 2009
Summary
High expression of soybean FRD3 genes enhances iron transport from root to shoot. This is crucial for improving iron uptake and preventing yield losses in crops grown on high-pH soils.
Area of Science:
- Plant Physiology
- Molecular Biology
- Agricultural Science
Background:
- Iron is essential for plant growth, but its deficiency is common in high-pH soils, leading to chlorosis and yield reduction in soybeans.
- Efficient iron translocation from roots to shoots, likely via ferric citrate in the xylem, is critical for overcoming iron deficiency.
- The FRD3 protein in Arabidopsis thaliana facilitates citrate efflux into the xylem, a key step in iron transport.
Purpose of the Study:
- To identify and characterize soybean genes homologous to Arabidopsis FRD3.
- To investigate the role of these soybean FRD3 genes in iron uptake and translocation.
- To explore the potential of FRD3 genes for improving iron efficiency in soybean breeding.
Main Methods:
- Identification and sequencing of two soybean FRD3 homologs, GmFRD3a and GmFRD3b.
- Analysis of GmFRD3a and GmFRD3b gene expression in response to iron deficiency in different soybean cultivars.
- Measurement of xylem citrate levels and iron solubility in xylem exudates of contrasting soybean lines.
Main Results:
- Both GmFRD3a and GmFRD3b were identified and shown to be induced by iron deficiency in the Williams 82 soybean cultivar.
- GmFRD3b expression was significantly higher in the iron-efficient Clark cultivar compared to its near-isogenic, iron-inefficient line (iso-Clark).
- Higher GmFRD3b expression correlated with increased xylem citrate levels and enhanced ferric iron solubility in Clark, facilitating iron translocation.
Conclusions:
- High expression of GmFRD3b is associated with efficient root-to-shoot iron translocation in soybeans.
- Xylem citrate levels, regulated by FRD3 gene expression, are vital for solubilizing and transporting iron.
- FRD3 genes represent promising targets for breeding iron-efficient soybean varieties to mitigate yield losses on calcareous soils.
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