Mutational reconstructed ferric chelate reductase confers enhanced tolerance in rice to iron deficiency in calcareous soil

• DOI: 10.1073/pnas.0610555104
• Publication Date: 2007-04-21T00:50:04Z
• Authors: Yasuhiro Ishimaru; Suyeon Kim; Takashi Tsukamoto; Hiroyuki Oki; Takanori Kobayashi; Satoshi Watanabe; Shinpei Matsuhashi; Michiko Takahashi; Hiromi Nakanishi; Satoshi Mori; Naoko K. Nishizawa
• Keywords: Genetically modified rice; Calcareous soils

Iron (Fe) deficiency is a worldwide agricultural problem on calcareous soils with low-Fe availability due to high soil pH. Rice plants use well documented phytosiderophore-based system (Strategy II) take up Fe from the and also possess direct Fe2+ transport system. are extremely susceptible supply, however, because of low phytosiderophore secretion Fe3+ reduction activity. A yeast chelate-reductase gene refre1/372, selected for better performance at pH, was fused promoter Fe-regulated transporter, OsIRT1, introduced into rice plants. The transgene expressed in response nutritional status roots transformants. Transgenic expressing refre1/372 showed higher activity Fe-uptake rate than vector controls under Fe-deficient conditions. Consequently, transgenic exhibited an enhanced tolerance 7.9x grain yield nontransformed soils. This report shows that enhancing normally have endogenous levels confers resistance deficiency.