title: ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12) Interacts with FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT) Linking Iron Deficiency and Oxidative Stress Responses.
abstract: Plants grown under iron (Fe)-deficient conditions induce a set of genes that enhance the efficiency of Fe uptake by the roots. In Arabidopsis (Arabidopsis thaliana), the central regulator of this response is the basic helix-loop-helix transcription factor FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT). FIT activity is regulated by protein-protein interactions, which also serve to integrate external signals that stimulate and possibly inhibit Fe uptake. In the search of signaling components regulating FIT function, we identified ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12), an abiotic stress-induced transcription factor. ZAT12 interacted with FIT, dependent on the presence of the ethylene-responsive element-binding factor-associated amphiphilic repression motif. ZAT12 protein was found expressed in the root early differentiation zone, where its abundance was modulated in a root layer-specific manner. In the absence of ZAT12, FIT expression was upregulated, suggesting a negative effect of ZAT12 on Fe uptake. Consistently, zat12 loss-of-function mutants had higher Fe content than the wild type at sufficient Fe. We found that under Fe deficiency, hydrogen peroxide (H2O2) levels were enhanced in a FIT-dependent manner. FIT protein, in turn, was stabilized by H2O2 but only in the presence of ZAT12, showing that H2O2 serves as a signal for Fe deficiency responses. We propose that oxidative stress-induced ZAT12 functions as a negative regulator of Fe acquisition. A model where H2O2 mediates the negative regulation of plant responses to prolonged stress might be applicable to a variety of stress conditions.
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Cham Thi Tuyet
authors.initials: CT
authors.lastname: Le
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Tzvetina
authors.initials: T
authors.lastname: Brumbarova
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Rumen
authors.initials: R
authors.lastname: Ivanov
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Claudia
authors.initials: C
authors.lastname: Stoof
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Eva
authors.identifier: http://orcid.org/0000-0001-8703-8439
authors.initials: E
authors.lastname: Weber
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Julia
authors.initials: J
authors.lastname: Mohrbacher
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.).
authors.forename: Claudia
authors.initials: C
authors.lastname: Fink-Straube
authors.affiliation: Department of Biosciences-Plant Biology, Saarland University, D-66123 Saarbruecken, Germany (C.T.T., T.B., R.I., E.W., J.M., P.B.);Institute of Botany (T.B., R.I., C.S., P.B.) and Cluster of Excellence on Plant Sciences (P.B.), Heinrich-Heine University, D-40225 Duesseldorf, Germany; andLeibniz Institute for New Materials, D-66123 Saarbruecken, Germany (C.F.-S.) petra.bauer@uni-duesseldorf.de.
authors.forename: Petra
authors.initials: P
authors.lastname: Bauer
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D007501:Iron / Q000378:metabolism*; D007976:Leupeptins / Q000494:pharmacology; D009154:Mutation; D018384:Oxidative Stress / Q000502:physiology*; D030821:Plants, Genetically Modified; D054730:Protein Interaction Domains and Motifs; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D006861:Hydrogen Peroxide; D007501:Iron; D007976:Leupeptins; D014157:Transcription Factors; C501411:FIT1 protein, Arabidopsis; C502133:ZAT12 protein, Arabidopsis; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde