title: Transcriptome analysis of intraspecific competition in Arabidopsis thaliana reveals organ-specific signatures related to nutrient acquisition and general stress response pathways.
abstract: BACKGROUND
  Plants are sessile and therefore have to perceive and adjust to changes in their environment. The presence of neighbours leads to a competitive situation where resources and space will be limited. Complex adaptive responses to such situation are poorly understood at the molecular level.
  
  
  RESULTS
  Using microarrays, we analysed whole-genome expression changes in Arabidopsis thaliana plants subjected to intraspecific competition. The leaf and root transcriptome was strongly altered by competition. Differentially expressed genes were enriched in genes involved in nutrient deficiency (mainly N, P, K), perception of light quality, and responses to abiotic and biotic stresses. Interestingly, performance of the generalist insect Spodoptera littoralis on densely grown plants was significantly reduced, suggesting that plants under competition display enhanced resistance to herbivory.
  
  
  CONCLUSIONS
  This study provides a comprehensive list of genes whose expression is affected by intraspecific competition in Arabidopsis. The outcome is a unique response that involves genes related to light, nutrient deficiency, abiotic stress, and defence responses.
authors.affiliation: Department of Plant Molecular Biology, University of Lausanne, Lausanne 1015, Switzerland.
authors.forename: Frédéric G
authors.initials: FG
authors.lastname: Masclaux
authors.forename: Friederike
authors.initials: F
authors.lastname: Bruessow
authors.forename: Fabian
authors.initials: F
authors.lastname: Schweizer
authors.forename: Caroline
authors.initials: C
authors.lastname: Gouhier-Darimont
authors.forename: Laurent
authors.initials: L
authors.lastname: Keller
authors.forename: Philippe
authors.initials: P
authors.lastname: Reymond
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D007814:Larva / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics*; D010758:Phosphorus / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D018411:Spodoptera / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*
chemical_list: D010937:Plant Growth Regulators; D010758:Phosphorus; D009584:Nitrogen