title: Root tip contact with low-phosphate media reprograms plant root architecture.
abstract: Plant roots are able to sense soil nutrient availability. In order to acquire heterogeneously distributed water and minerals, they optimize their root architecture. One poorly understood plant response to soil phosphate (P(i)) deficiency is a reduction in primary root growth with an increase in the number and length of lateral roots. Here we show that physical contact of the Arabidopsis thaliana primary root tip with low-P(i) medium is necessary and sufficient to arrest root growth. We further show that loss-of-function mutations in Low Phosphate Root1 (LPR1) and its close paralog LPR2 strongly reduce this inhibition. LPR1 was previously mapped as a major quantitative trait locus (QTL); the molecular origin of this QTL is explained by the differential allelic expression of LPR1 in the root cap. These results provide strong evidence for the involvement of the root cap in sensing nutrient deficiency, responding to it, or both. LPR1 and LPR2 encode multicopper oxidases (MCOs), highlighting the essential role of MCOs for plant development.
authors.affiliation: Laboratoire de Biologie du Développement des Plantes, Département d'Ecophysiologie Végétale et de Microbiologie, Unité Mixte de Recherche 6191 Commissariat à l'Energie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), Cedex, France.
authors.forename: Sergio
authors.initials: S
authors.lastname: Svistoonoff
authors.forename: Audrey
authors.initials: A
authors.lastname: Creff
authors.forename: Matthieu
authors.initials: M
authors.lastname: Reymond
authors.forename: Cécile
authors.initials: C
authors.lastname: Sigoillot-Claude
authors.forename: Lilian
authors.initials: L
authors.lastname: Ricaud
authors.forename: Aline
authors.initials: A
authors.lastname: Blanchet
authors.forename: Laurent
authors.initials: L
authors.lastname: Nussaume
authors.forename: Thierry
authors.initials: T
authors.lastname: Desnos
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003001:Cloning, Molecular; D003300:Copper / Q000737:chemistry; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D018518:Plant Root Cap / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development*; D040641:Quantitative Trait Loci; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012987:Soil / Q000032:analysis
chemical_list: D029681:Arabidopsis Proteins; D010710:Phosphates; D012333:RNA, Messenger; D018749:RNA, Plant; D012987:Soil; D003300:Copper; D010088:Oxidoreductases; C024748:copper oxidase