title: Iron biofortification of myanmar rice.
abstract: Iron (Fe) deficiency elevates human mortality rates, especially in developing countries. In Myanmar, the prevalence of Fe-deficient anemia in children and pregnant women are 75 and 71%, respectively. Myanmar people have one of the highest per capita rice consumption rates globally. Consequently, production of Fe-biofortified rice would likely contribute to solving the Fe-deficiency problem in this human population. To produce Fe-biofortified Myanmar rice by transgenic methods, we first analyzed callus induction and regeneration efficiencies in 15 varieties that are presently popular because of their high-yields or high-qualities. Callus formation and regeneration efficiency in each variety was strongly influenced by types of culture media containing a range of 2,4-dichlorophenoxyacetic acid concentrations. The Paw San Yin variety, which has a high-Fe content in polished seeds, performed well in callus induction and regeneration trials. Thus, we transformed this variety using a gene expression cassette that enhanced Fe transport within rice plants through overexpression of the nicotianamine synthase gene HvNAS1, Fe flow to the endosperm through the Fe(II)-nicotianamine transporter gene OsYSL2, and Fe accumulation in endosperm by the Fe storage protein gene SoyferH2. A line with a transgene insertion was successfully obtained. Enhanced expressions of the introduced genes OsYSL2, HvNAS1, and SoyferH2 occurred in immature T2 seeds. The transformants accumulated 3.4-fold higher Fe concentrations, and also 1.3-fold higher zinc concentrations in T2 polished seeds compared to levels in non-transgenic rice. This Fe-biofortified rice has the potential to reduce Fe-deficiency anemia in millions of Myanmar people without changing food habits and without introducing additional costs.
authors.affiliation: Laboratory of Plant Biotechnology, Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo , Japan ; Laboratory of Plant Cell Technology, Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University , Nonoichi, Ishikawa , Japan.
authors.forename: May Sann
authors.initials: MS
authors.lastname: Aung
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masuda
authors.forename: Takanori
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nakanishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamakawa
authors.forename: Naoko K
authors.initials: NK
authors.lastname: Nishizawa
keywords: Myanmar rice; OsYSL2; anemia; biofortification; ferritin; iron; nicotianamine; rice transformation