title: Nicotianamine is a major player in plant Zn homeostasis.
abstract: Nicotianamine (NA) is among the most studied plant metal chelators. A large body of evidence supports its crucial role for Fe distribution in plants and as a precursor of phytosiderophore synthesis in grasses. NA forms stable complexes in vitro not only with Fe(II) and Fe(III) but also with various other divalent metal cations including Zn(II). Early observations indicated a possible contribution of NA to Zn trafficking in plants. Numerous studies on transgenic monocot and dicot plants with modulated NA levels have since then reported Zn accumulation phenotypes. NAS genes were shown to represent promising targets for biofortification efforts. For instance, NA was found to bind Zn in rice grains in a form bioavailable for humans. Recently, additional strong support for the existence of Zn-NA complexes in planta has been obtained in rice, Arabidopsis thaliana and the Zn hyperaccumulating plant A. halleri. We review the evidence for a role of NA in the intercellular and long-distance transport of Zn in plants and discuss open questions.
authors.affiliation: Department of Plant Physiology, University of Bayreuth, Bayreuth, Germany. stephan.clemens@uni-bayreuth.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Clemens
authors.forename: Ulrich
authors.initials: U
authors.lastname: Deinlein
authors.forename: Hassan
authors.initials: H
authors.lastname: Ahmadi
authors.forename: Stephan
authors.initials: S
authors.lastname: Höreth
authors.forename: Shimpei
authors.initials: S
authors.lastname: Uraguchi
mesh_terms: D017360:Arabidopsis / Q000378:metabolism; D001383:Azetidinecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology; D010944:Plants / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: C082893:nicotianamine; D001383:Azetidinecarboxylic Acid; D015032:Zinc