title: An Arabidopsis ABC Transporter Mediates Phosphate Deficiency-Induced Remodeling of Root Architecture by Modulating Iron Homeostasis in Roots.
abstract: The remodeling of root architecture is a major developmental response of plants to phosphate (Pi) deficiency and is thought to enhance a plant's ability to forage for the available Pi in topsoil. The underlying mechanism controlling this response, however, is poorly understood. In this study, we identified an Arabidopsis mutant, hps10 (hypersensitive to Pi starvation 10), which is morphologically normal under Pi sufficient condition but shows increased inhibition of primary root growth and enhanced production of lateral roots under Pi deficiency. hps10 is a previously identified allele (als3-3) of the ALUMINUM SENSITIVE3 (ALS3) gene, which is involved in plant tolerance to aluminum toxicity. Our results show that ALS3 and its interacting protein AtSTAR1 form an ABC transporter complex in the tonoplast. This protein complex mediates a highly electrogenic transport in Xenopus oocytes. Under Pi deficiency, als3 accumulates higher levels of Fe3+in its roots than the wild type does. In Arabidopsis, LPR1 (LOW PHOSPHATE ROOT1) and LPR2 encode ferroxidases, which when mutated, reduce Fe3+accumulation in roots and cause root growth to be insensitive to Pi deficiency. Here, we provide compelling evidence showing that ALS3 cooperates with LPR1/2 to regulate Pi deficiency-induced remodeling of root architecture by modulating Fe homeostasis in roots.
authors.affiliation: Ministry of Education Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Dong
authors.affiliation: USDA-ARS, Robert Holley Center for Agriculture and Health, Cornell University, Ithaca, NY 14580, USA.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Piñeros
authors.affiliation: Ministry of Education Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaoxuan
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Horticulture, Purdue University, West Lafayette, IN 47907-2010, USA.
authors.forename: Haibing
authors.initials: H
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA.
authors.forename: Angus S
authors.initials: AS
authors.lastname: Murphy
authors.affiliation: Global Institute for Food Security, University of Saskatchewan, Saskatoon S7N 4J8, Canada.
authors.forename: Leon V
authors.initials: LV
authors.lastname: Kochian
authors.affiliation: Ministry of Education Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China. Electronic address: liu-d@mail.tsinghua.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D006706:Homeostasis; D007501:Iron / Q000378:metabolism*; D009154:Mutation; D010088:Oxidoreductases / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*
chemical_list: C500787:ALS3 protein, Arabidopsis; D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D010710:Phosphates; D007501:Iron; C543910:LPR1 protein, Arabidopsis; D010088:Oxidoreductases
keywords: ABC transporter; ALUMINUM SENSITIVE3; AtSTAR1; iron homeostasis; phosphate deficiency; root architecture