Biofortified indica rice attains iron and zinc nutrition dietary targets in the field

Sci Rep. 2016 Jan 25:6:19792. doi: 10.1038/srep19792.

Abstract

More than two billion people are micronutrient deficient. Polished grains of popular rice varieties have concentration of approximately 2 μg g(-1) iron (Fe) and 16 μg g(-1) zinc (Zn). The HarvestPlus breeding programs for biofortified rice target 13 μg g(-1) Fe and 28 μg g(-1) Zn to reach approximately 30% of the estimated average requirement (EAR). Reports on engineering Fe content in rice have shown an increase up to 18 μg g(-1) in glasshouse settings; in contrast, under field conditions, 4 μg g(-1) was the highest reported concentration. Here, we report on selected transgenic events, field evaluated in two countries, showing 15 μg g(-1) Fe and 45.7 μg g(-1) Zn in polished grain. Rigorous selection was applied to 1,689 IR64 transgenic events for insert cleanliness and, trait and agronomic performances. Event NASFer-274 containing rice nicotianamine synthase (OsNAS2) and soybean ferritin (SferH-1) genes showed a single locus insertion without a yield penalty or altered grain quality. Endosperm Fe and Zn enrichment was visualized by X-ray fluorescence imaging. The Caco-2 cell assay indicated that Fe is bioavailable. No harmful heavy metals were detected in the grain. The trait remained stable in different genotype backgrounds.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Colombia
  • Edible Grain / chemistry
  • Endosperm / chemistry
  • Food, Fortified*
  • Gene Expression
  • Genotype
  • Iron*
  • Metals, Heavy / chemistry
  • Micronutrients*
  • Oryza / chemistry*
  • Oryza / genetics
  • Philippines
  • Plants, Genetically Modified
  • Quantitative Trait, Heritable
  • Seeds
  • Transgenes
  • Zinc*

Substances

  • Metals, Heavy
  • Micronutrients
  • Iron
  • Zinc