Localization of metals and metal ligands in rice seeds overexpressing nicotianamine synthase and/or barley nicotianamine amino transferase

1 .pdf file [5 Figs.] copy of the original from the authors. Creative Commons License Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).Biofortification of rice seeds with micronutrients has the potential to mitigate deficiencies of Fe and Zn in humans. Increasing the synthesis of the metal ligands nicotianamine (NA) and deoxymugineic acid (DMA) in rice plants leads to increases in seed Fe and Zn, and high levels of NA in rice seeds enhance intestinal Fe and Zn absorption. Since the high metal content embryo and bran parts of the rice seed are removed during processing (polishing), the localization of the accumulation of NA, DMA and metals in biofortified seeds is relevant. Laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) provides spatial localization of elements in tissues, with a resolution in the μm range, and allows for an accurate absolute elemental quantification NA and DMA have been successfully determined in plant tissues by molecular specific-MS techniques coupled to hydrophilic interaction liquid chromatography (HILIC). The aim of this work was to investigate the changes in the localization of metals and metal ligands in rice seeds induced by the overexpression of rice nicotianamine synthase (OsNAS1) and/or barley nicotianamine amino transferase (HvNAATb) genes.Supported by the Spanish Ministry of Economy and Competitiveness [project AGL2013-42175-R to JA, and BIO2014-54426-P and BIO2014-54441-P to PC), the Commission of European Communities (European Union Framework 7 European Research Council IDEAS, Advanced Grant Program-BIOFORCE and Proof of Concept Grant Multinutrient Maize, to PC) and the Aragón Government (group A03). P.D.-B. was supported by a MINECO-FPI contract.Peer reviewe