title: Iron-dependent callose deposition adjusts root meristem maintenance to phosphate availability.
abstract: Plant root development is informed by numerous edaphic cues. Phosphate (Pi) availability impacts the root system architecture by adjusting meristem activity. However, the sensory mechanisms monitoring external Pi status are elusive. Two functionally interacting Arabidopsis genes, LPR1 (ferroxidase) and PDR2 (P5-type ATPase), are key players in root Pi sensing, which is modified by iron (Fe) availability. We show that the LPR1-PDR2 module facilitates, upon Pi limitation, cell-specific apoplastic Fe and callose deposition in the meristem and elongation zone of primary roots. Expression of cell-wall-targeted LPR1 determines the sites of Fe accumulation as well as callose production, which interferes with symplastic communication in the stem cell niche, as demonstrated by impaired SHORT-ROOT movement. Antagonistic interactions of Pi and Fe availability control primary root growth via meristem-specific callose formation, likely triggered by LPR1-dependent redox signaling. Our results link callose-regulated cell-to-cell signaling in root meristems to the perception of an abiotic cue.
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Müller
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Toev
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Heisters
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
authors.forename: Janine
authors.initials: J
authors.lastname: Teller
authors.affiliation: Department of Materials, University of Oxford, Oxford OX1 3PH, UK.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Moore
authors.affiliation: Biocenter, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Hause
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
authors.forename: Dhurvas Chandrasekaran
authors.initials: DC
authors.lastname: Dinesh
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Bürstenbinder
authors.affiliation: Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, 06120 Halle (Saale), Germany; Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; Department of Plant Sciences, University of California, Davis, Davis, CA 95616, USA. Electronic address: sabel@ipb-halle.de.
authors.forename: Steffen
authors.initials: S
authors.lastname: Abel
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D017360:Arabidopsis / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002450:Cell Communication; D018506:Gene Expression Regulation, Plant; D005936:Glucans / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D018519:Meristem / Q000254:growth & development*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D005936:Glucans; D010710:Phosphates; C048306:callose; D007501:Iron; C543910:LPR1 protein, Arabidopsis; D010088:Oxidoreductases; D000251:Adenosine Triphosphatases; C543909:PDR2 protein, Arabidopsis