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Professor of Biological Sciences
Molecular Genetics of Mineral Homeostasis
Increasing the ability of plants to take up essential minerals could have a
dramatic impact on both plant and human health. For example, iron
deficiency afflicts over 3 billion people worldwide and plants are the
principal source of iron in most diets. We have employed the tools
available in the model plant Arabidopsis to identify genes involved in metal
homeostasis. We have discovered that the iron reductase FRO2 and the iron
transporter IRT1 are expressed in iron deficient plant roots and are
responsible for uptake of iron from the soil. IRT1 is one of the founding
members of the ZIP family of metal transporters, with representatives in
bacteria, fungi and animals. Our lab is also currently trying to unravel
how both plant and bacterial cells perceive iron status and translate that
information into changes in gene expression. We have recently identified
a transcription factor, FIT1, that controls the iron deficiency response in
Arabidopsis.
In addition, the bacterial side of our lab is trying to decipher the early
signals that help set up the nitrogen-fixing symbiosis between bacteria of the
genus Bradyrhizobium and its host, soybeans. We are particularly
interested in the period after the bacteria have entered the host via infection
threads. We are characterizing an interesting mutant that is unable to
set up a persistent infection. This mutant no longer expresses an
iron-regulated operon that functions in free-living bacteria to take up
iron.
Visit the Guerinot Lab
website
Publications
Kim, SA, T. Punshon, A. Lanzirotti, L. Li, J. Alonso, J. Ecker, J. Kaplan
and M.L. Guerinot. 2006. Localization of iron in Arabidopsis seed requires the
vacuolar membrane transporter VIT1. Science 314: 1295-1298. (See the
accompanying Perspectives article: Gitlin, J.D. 2006. Distributing Nutrition.
314:1252-1253)
Eide, D.J., S. Clark, T.M. Nair, M. Gehl, M. Gribskov, M.L. Guerinot and
J.F. Harper. 2005. Characterization of the yeast ionome: a genome-wide analysis
of nutrient mineral and trace element homeostasis. Genome Biology 6:R77
[doi:10.1186/gb-2005-6-9-r77]
Benson, H.P., E. Boncompagni and M.L. Guerinot. 2005. An iron uptake operon
required for proper nodule development in the Bradyrhizobium japonicum/ soybean
symbiosis. Mol. Plant Microbe Interact. 18:950-959.
Colangelo, E. and M.L. Guerinot. 2004. The essential bHLH protein FIT1 is
required for the iron deficiency response. Plant Cell 16:3400-3412.
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