title: Genetic modification of low phytic acid 1-1 maize to enhance iron content and bioavailability.
abstract: High phytate content in staple food crops is a major barrier to successful iron biofortification. We have exploited the low phytic acid 1-1 (lpa1-1) mutant of maize to generate transgenic plants with up-to 70 μg/g seed iron through the endosperm-specific overexpression of soybean ferritin, resulting in more than 2-fold improvement in iron bioavailability. The levels of bioavailable seed iron achieved in this study greatly exceed any achieved thus far and closely approach values estimated to have a nutritional impact on target populations. Gene expression studies reveal a large induction of the YS1 transporter in leaves and severe repression of an iron acquisition gene DMAS1 in roots, suggesting significant alterations in the iron homeostatic mechanisms in transgenic lpa1-1. Furthermore, preliminary tests show that the high-iron lpa1-1 seeds have higher germination rates and seedling vigor when compared to those of the nontransgenic seeds, which may help improve their value to plant breeders.
authors.affiliation: Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011, United States. maluru@iastate.edu
authors.forename: Maneesha R
authors.initials: MR
authors.lastname: Aluru
authors.forename: Steve R
authors.initials: SR
authors.lastname: Rodermel
authors.forename: Manju B
authors.initials: MB
authors.lastname: Reddy
mesh_terms: D001682:Biological Availability; D005527:Food, Fortified; D007501:Iron / Q000032:analysis* / Q000493:pharmacokinetics*; D010833:Phytic Acid / Q000032:analysis*; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010833:Phytic Acid; D007501:Iron