Open AccessMetabolic engineering of bread wheat improves grain iron concentration and bioavailability
Author(s) -
Beasley Jesse T.,
Bonneau Julien P.,
SánchezPalacios Jose T.,
MorenoMoyano Laura T.,
Callahan Damien L.,
Tako Elad,
Glahn Raymond P.,
Lombi Enzo,
Johnson Alexander A. T.
Publication year - 2019
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13074
Subject(s) - biofortification , endosperm , bioavailability , micronutrient , oryza sativa , food science , biology , starch , zinc , agronomy , starch synthase , botany , chemistry , biochemistry , amylopectin , gene , bioinformatics , organic chemistry , amylose
Summary Bread wheat ( Triticum aestivum L.) is cultivated on more land than any other crop and produces a fifth of the calories consumed by humans. Wheat endosperm is rich in starch yet contains low concentrations of dietary iron (Fe) and zinc (Zn). Biofortification is a micronutrient intervention aimed at increasing the density and bioavailability of essential vitamins and minerals in staple crops; Fe biofortification of wheat has proved challenging. In this study we employed constitutive expression ( CE ) of the rice ( Oryza sativa L.) nicotianamine synthase 2 ( Os NAS 2 ) gene in bread wheat to up‐regulate biosynthesis of two low molecular weight metal chelators – nicotianamine ( NA ) and 2′‐deoxymugineic acid ( DMA ) – that play key roles in metal transport and nutrition. The CE ‐ Os NAS 2 plants accumulated higher concentrations of grain Fe, Zn, NA and DMA and synchrotron X‐ray fluorescence microscopy ( XFM ) revealed enhanced localization of Fe and Zn in endosperm and crease tissues, respectively. Iron bioavailability was increased in white flour milled from field‐grown CE ‐ Os NAS 2 grain and positively correlated with NA and DMA concentrations.