title: Molecular speciation and tissue compartmentation of zinc in durum wheat grains with contrasting nutritional status.
abstract: Low concentration of zinc (Zn) in the endosperm of cereals is a major factor contributing to Zn deficiency in human populations. We have investigated how combined Zn and nitrogen (N) fertilization affects the speciation and localization of Zn in durum wheat (Triticum durum). Zn-binding proteins were analysed with liquid chromatography ICP-MS and Orbitrap MS(2) , respectively. Laser ablation ICP-MS with simultaneous Zn, sulphur (S) and phosphorus (P) detection was used for bioimaging of Zn and its potential ligands. Increasing the Zn and N supply had a major impact on the Zn concentration in the endosperm, reaching concentrations higher than current breeding targets. The S concentration also increased, but S was only partly co-localized with Zn. The mutual Zn and S enrichment was reflected in substantially more Zn bound to small cysteine-rich proteins (apparent size 10-30 kDa), whereas the response of larger proteins (apparent size > 50 kDa) was only modest. Most of the Zn-responsive proteins were associated with redox- and stress-related processes. This study offers a methodological platform to deepen the understanding of processes behind endosperm Zn enrichment. Novel information is provided on how the localization and speciation of Zn is modified during Zn biofortification of grains.
authors.affiliation: Plant and Soil Science Section, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, DK-1871, Denmark.
authors.forename: Daniel Pergament
authors.initials: DP
authors.lastname: Persson
authors.affiliation: Plant and Soil Science Section, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, DK-1871, Denmark.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: de Bang
authors.affiliation: Plant and Soil Science Section, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, DK-1871, Denmark.
authors.forename: Pai R
authors.initials: PR
authors.lastname: Pedas
authors.affiliation: Faculty of Engineering & Natural Science, Sabanci University, Istanbul, TR-34956, Turkey.
authors.forename: Umit Baris
authors.initials: UB
authors.lastname: Kutman
authors.affiliation: Faculty of Engineering & Natural Science, Sabanci University, Istanbul, TR-34956, Turkey.
authors.forename: Ismail
authors.initials: I
authors.lastname: Cakmak
authors.affiliation: Plant and Soil Science Section, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, DK-1871, Denmark.
authors.forename: Birgit
authors.initials: B
authors.lastname: Andersen
authors.affiliation: Agricultural and Environmental Proteomics, Department of Systems Biology, Technical University of Denmark, Building 301, Søltofts plads, Kongens Lyngby, DK-2800, Denmark.
authors.forename: Christine
authors.initials: C
authors.lastname: Finnie
authors.affiliation: Plant and Soil Science Section, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, DK-1871, Denmark.
authors.forename: Jan K
authors.initials: JK
authors.lastname: Schjoerring
authors.affiliation: Plant and Soil Science Section, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, DK-1871, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Husted
mesh_terms: D056625:Endosperm / Q000378:metabolism; D013058:Mass Spectrometry; D009584:Nitrogen / Q000378:metabolism; D009752:Nutritional Status; D009928:Organ Specificity; D010940:Plant Proteins / Q000378:metabolism; D012639:Seeds / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism; D014908:Triticum / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013455:Sulfur; D015032:Zinc; D009584:Nitrogen
keywords: durum wheat; endosperm; inductively coupled plasma-mass spectrometry (ICP-MS); laser ablation (LA); speciation; zinc (Zn) localization; zinc (Zn)-binding proteins