title: Structure and expression profile of the phosphate Pht1 transporter gene family in mycorrhizal Populus trichocarpa.
abstract: Gene networks involved in inorganic phosphate (Pi) acquisition and homeostasis in woody perennial species able to form mycorrhizal symbioses are poorly known. Here, we describe the features of the 12 genes coding for Pi transporters of the Pht1 family in poplar (Populus trichocarpa). Individual Pht1 transporters play distinct roles in acquiring and translocating Pi in different tissues of mycorrhizal and nonmycorrhizal poplar during different growth conditions and developmental stages. Pi starvation triggered the up-regulation of most members of the Pht1 family, especially PtPT9 and PtPT11. PtPT9 and PtPT12 showed a striking up-regulation in ectomycorrhizas and endomycorrhizas, whereas PtPT1 and PtPT11 were strongly down-regulated. PtPT10 transcripts were highly abundant in arbuscular mycorrhiza (AM) roots only. PtPT8 and PtPT10 are phylogenetically associated to the AM-inducible Pht1 subfamily I. The analysis of promoter sequences revealed conserved motifs similar to other AM-inducible orthologs in PtPT10 only. To gain more insight into gene regulatory mechanisms governing the AM symbiosis in woody plant species, the activation of the poplar PtPT10 promoter was investigated and detected in AM of potato (Solanum tuberosum) roots. These results indicated that the regulation of AM-inducible Pi transporter genes is conserved between perennial woody and herbaceous plant species. Moreover, poplar has developed an alternative Pi uptake pathway distinct from AM plants, allowing ectomycorrhizal poplar to recruit PtPT9 and PtPT12 to cope with limiting Pi concentrations in forest soils.
authors.affiliation: Unité Mixte de Recherche 1136 Institut National de la Recherche Agronomique/Nancy Université Interactions Arbres/Micro-organismes, Institut National de la Recherche Agronomique Nancy, 54280 Champenoux, France.
authors.forename: Verónica
authors.initials: V
authors.lastname: Loth-Pereda
authors.forename: Elena
authors.initials: E
authors.lastname: Orsini
authors.forename: Pierre-Emmanuel
authors.initials: PE
authors.lastname: Courty
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lota
authors.forename: Annegret
authors.initials: A
authors.lastname: Kohler
authors.forename: Loic
authors.initials: L
authors.lastname: Diss
authors.forename: Damien
authors.initials: D
authors.lastname: Blaudez
authors.forename: Michel
authors.initials: M
authors.lastname: Chalot
authors.forename: Uwe
authors.initials: U
authors.lastname: Nehls
authors.forename: Marcel
authors.initials: M
authors.lastname: Bucher
authors.forename: Francis
authors.initials: F
authors.lastname: Martin
mesh_terms: D015169:Colony Count, Microbial; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D005838:Genotype; D055137:Glomeromycota / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D005966:Glucuronidase / Q000378:metabolism; D058977:Molecular Sequence Annotation; D005810:Multigene Family / Q000235:genetics*; D038821:Mycorrhizae / Q000187:drug effects / Q000502:physiology*; D028061:Phosphate Transport Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D010710:Phosphates / Q000494:pharmacology; D010802:Phylogeny; D030821:Plants, Genetically Modified; D032107:Populus / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity
chemical_list: D028061:Phosphate Transport Proteins; D010710:Phosphates; D012333:RNA, Messenger; D005966:Glucuronidase