Aarhus University Seal / Aarhus Universitets segl

Iron and ferritin accumulate in separate cellular locations in Phaseolus seeds

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

  • Cristina Cvitanich, Denmark
  • Wojciech J Przybylowicz, iThemba LABS, South Africa
  • Dorian Fabian Urbanski, Denmark
  • Anna Malgorzata Jurkiewicz, Denmark
  • Jolanta Mesjasz-Przybylowicz, iThemba LABS, South Africa
  • Matthew W. Blair, Center for Tropical Agriculture (CIAT), Cali, Colombia
  • Carolina Astudillo, Center for Tropical Agriculture (CIAT), Cali, Colombia
  • Erik Østergaard Jensen
  • Jens Stougaard
  • Department of Molecular Biology

Background

Iron is an important micronutrient for all living organisms. Almost 25% of the world's population is affected by iron deficiency, a leading cause of anemia. In plants, iron deficiency leads to chlorosis and reduced yield. Both animals and plants may suffer from iron deficiency when their diet or environment lacks bioavailable iron. A sustainable way to reduce iron malnutrition in humans is to develop staple crops with increased content of bioavailable iron. Knowledge of where and how iron accumulates in seeds of crop plants will increase the understanding of plant iron metabolism and will assist in the production of staples with increased bioavailable iron.

Results

Here we reveal the distribution of iron in seeds of three Phaseolus species including thirteen genotypes of P. vulgaris, P. coccineus, and P. lunatus. We showed that high concentrations of iron accumulate in cells surrounding the provascular tissue of P. vulgaris and P. coccineus seeds. Using the Perls' Prussian blue method, we were able to detect iron in the cytoplasm of epidermal cells, cells near the epidermis, and cells surrounding the provascular tissue. In contrast, the protein ferritin that has been suggested as the major iron storage protein in legumes was only detected in the amyloplasts of the seed embryo. Using the non-destructive micro-PIXE (Particle Induced X-ray Emission) technique we show that the tissue in the proximity of the provascular bundles holds up to 500 mg kg-1 of iron, depending on the genotype. In contrast to P. vulgaris and P. coccineus, we did not observe iron accumulation in the cells surrounding the provascular tissues of P. lunatus cotyledons. A novel iron-rich genotype, NUA35, with a high concentration of iron both in the seed coat and cotyledons was bred from a cross between an Andean and a Mesoamerican genotype.

Conclusions

The presented results emphasize the importance of complementing research in model organisms with analysis in crop plants and they suggest that iron distribution criteria should be integrated into selection strategies for bean biofortification.

Original languageEnglish
JournalB M C Plant Biology
Volume10
Issue26
ISSN1471-2229
Publication statusPublished - 2010

See relations at Aarhus University Citationformats

ID: 19277656