title: Diversity in expression of phosphorus (P) responsive genes in Cucumis melo L.
abstract: BACKGROUND
  Phosphorus (P) is a major limiting nutrient for plant growth in many soils. Studies in model species have identified genes involved in plant adaptations to low soil P availability. However, little information is available on the genetic bases of these adaptations in vegetable crops. In this respect, sequence data for melon now makes it possible to identify melon orthologues of candidate P responsive genes, and the expression of these genes can be used to explain the diversity in the root system adaptation to low P availability, recently observed in this species.
  
  
  RESULTS
  Transcriptional responses to P starvation were studied in nine diverse melon accessions by comparing the expression of eight candidate genes (Cm-PAP10.1, Cm-PAP10.2, Cm-RNS1, Cm-PPCK1, Cm-transferase, Cm-SQD1, Cm-DGD1 and Cm-SPX2) under P replete and P starved conditions. Differences among melon accessions were observed in response to P starvation, including differences in plant morphology, P uptake, P use efficiency (PUE) and gene expression. All studied genes were up regulated under P starvation conditions. Differences in the expression of genes involved in P mobilization and remobilization (Cm-PAP10.1, Cm-PAP10.2 and Cm-RNS1) under P starvation conditions explained part of the differences in P uptake and PUE among melon accessions. The levels of expression of the other studied genes were diverse among melon accessions, but contributed less to the phenotypical response of the accessions.
  
  
  CONCLUSIONS
  This is the first time that these genes have been described in the context of P starvation responses in melon. There exists significant diversity in gene expression levels and P use efficiency among melon accessions as well as significant correlations between gene expression levels and phenotypical measurements.
authors.affiliation: Centro de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Valencia, Spain. anfifer@btc.upv.es
authors.forename: Ana
authors.initials: A
authors.lastname: Fita
authors.forename: Helen C
authors.initials: HC
authors.lastname: Bowen
authors.forename: Rory M
authors.initials: RM
authors.lastname: Hayden
authors.forename: Fernando
authors.initials: F
authors.lastname: Nuez
authors.forename: Belén
authors.initials: B
authors.lastname: Picó
authors.forename: John P
authors.initials: JP
authors.lastname: Hammond
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D018533:Biomass; D028463:Cucumis melo / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D050356:Lipid Metabolism / Q000235:genetics; D008563:Membrane Lipids / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D054647:Nutrigenomics; D010641:Phenotype; D010758:Phosphorus / Q000172:deficiency* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics
chemical_list: D008563:Membrane Lipids; D010940:Plant Proteins; D010758:Phosphorus