title: Bypassing Iron Storage in Endodermal Vacuoles Rescues the Iron Mobilization Defect in the natural resistance associated-macrophage protein3natural resistance associated-macrophage protein4 Double Mutant.
abstract: To improve seed iron (Fe) content and bioavailability, it is crucial to decipher the mechanisms that control Fe storage during seed development. In Arabidopsis (Arabidopsis thaliana) seeds, most Fe is concentrated in insoluble precipitates, with phytate in the vacuoles of cells surrounding the vasculature of the embryo. NATURAL RESISTANCE ASSOCIATED-MACROPHAGE PROTEIN3 (AtNRAMP3) and AtNRAMP4 function redundantly in Fe retrieval from vacuoles during germination. When germinated under Fe-deficient conditions, development of the nramp3nramp4 double mutant is arrested as a consequence of impaired Fe mobilization. To identify novel genes involved in seed Fe homeostasis, we screened an ethyl methanesulfonate-mutagenized population of nramp3nramp4 seedlings for mutations suppressing their phenotypes on low Fe. Here, we report that, among the suppressors, two independent mutations in the VACUOLAR IRON TRANSPORTER1 (AtVIT1) gene caused the suppressor phenotype. The AtVIT1 transporter is involved in Fe influx into vacuoles of endodermal and bundle sheath cells. This result establishes a functional link between Fe loading in vacuoles by AtVIT1 and its remobilization by AtNRAMP3 and AtNRAMP4. Moreover, analysis of subcellular Fe localization indicates that simultaneous disruption of AtVIT1, AtNRAMP3, and AtNRAMP4 limits Fe accumulation in vacuolar globoids.
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Viviane
authors.initials: V
authors.lastname: Mary
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Magali
authors.initials: M
authors.lastname: Schnell Ramos
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Cynthia
authors.initials: C
authors.lastname: Gillet
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Socha
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Jérôme
authors.initials: J
authors.lastname: Giraudat
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Astrid
authors.identifier: http://orcid.org/0000-0001-9603-7710
authors.initials: A
authors.lastname: Agorio
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Sylvain
authors.initials: S
authors.lastname: Merlot
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Colin
authors.initials: C
authors.lastname: Clairet
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Sun A
authors.initials: SA
authors.lastname: Kim
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Tracy
authors.initials: T
authors.lastname: Punshon
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.).
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Guerinot
authors.affiliation: Institute for Integrative Biology of the Cell, Saclay Plant Sciences, Université Paris-Saclay, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Paris-Sud, F-91198 Gif-sur-Yvette, France (V.M., M.S.R., C.G., J.G., A.A., S.M., C.C., S.T.); andDepartment of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755 (A.L.S., S.A.K., T.P., M.L.G.) sebastien.thomine@i2bc.paris-saclay.fr.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Thomine
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001692:Biological Transport; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism; D018548:Cotyledon / Q000187:drug effects / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D017343:Genes, Plant; D016153:Genes, Suppressor; D018525:Germination / Q000187:drug effects; D007501:Iron / Q000378:metabolism* / Q000494:pharmacology; D008954:Models, Biological; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D019441:Plant Epidermis / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D013052:Spectrometry, X-Ray Emission; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D027682:Cation Transport Proteins; C408073:NRAMP4 protein, Arabidopsis; C408072:Nramp3 protein, Arabidopsis; D012333:RNA, Messenger; D007501:Iron