title: Iron- and ferritin-dependent reactive oxygen species distribution: impact on Arabidopsis root system architecture.
abstract: Iron (Fe) homeostasis is integrated with the production of reactive oxygen species (ROS), and distribution at the root tip participates in the control of root growth. Excess Fe increases ferritin abundance, enabling the storage of Fe, which contributes to protection of plants against Fe-induced oxidative stress. AtFer1 and AtFer3 are the two ferritin genes expressed in the meristematic zone, pericycle and endodermis of the Arabidopsis thaliana root, and it is in these regions that we observe Fe stained dots. This staining disappears in the triple fer1-3-4 ferritin mutant. Fe excess decreases primary root length in the same way in wild-type and in fer1-3-4 mutant. In contrast, the Fe-mediated decrease of lateral root (LR) length and density is enhanced in fer1-3-4 plants due to a defect in LR emergence. We observe that this interaction between excess Fe, ferritin, and root system architecture (RSA) is in part mediated by the H2O2/O2·- balance between the root cell proliferation and differentiation zones regulated by the UPB1 transcription factor. Meristem size is also decreased in response to Fe excess in ferritin mutant plants, implicating cell cycle arrest mediated by the ROS-activated SMR5/SMR7 cyclin-dependent kinase inhibitors pathway in the interaction between Fe and RSA.
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, SupAgro. Bat 7, 2 place Viala, 34060 Montpellier Cedex 1, France.
authors.forename: Guilhem
authors.initials: G
authors.lastname: Reyt
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, SupAgro. Bat 7, 2 place Viala, 34060 Montpellier Cedex 1, France.
authors.forename: Soukaina
authors.initials: S
authors.lastname: Boudouf
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, SupAgro. Bat 7, 2 place Viala, 34060 Montpellier Cedex 1, France.
authors.forename: Jossia
authors.initials: J
authors.lastname: Boucherez
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, SupAgro. Bat 7, 2 place Viala, 34060 Montpellier Cedex 1, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gaymard
authors.affiliation: Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, SupAgro. Bat 7, 2 place Viala, 34060 Montpellier Cedex 1, France. Electronic address: briat@supagro.inra.fr.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Briat
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005293:Ferritins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007501:Iron / Q000378:metabolism*; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C582321:FER1 protein, Arabidopsis; C000604914:Fer3 protein, Arabidopsis; C000604915:Fer4 protein, Arabidopsis; D017382:Reactive Oxygen Species; D005293:Ferritins; D007501:Iron
keywords: development; ferritins; iron; oxidative stress; reactive oxygen species balance; roots