title: Cytoplasmic genome substitution in wheat affects the nuclear-cytoplasmic cross-talk leading to transcript and metabolite alterations.
abstract: BACKGROUND
  Alloplasmic lines provide a unique tool to study nuclear-cytoplasmic interactions. Three alloplasmic lines, with nuclear genomes from Triticum aestivum and harboring cytoplasm from Aegilops uniaristata, Aegilops tauschii and Hordeum chilense, were investigated by transcript and metabolite profiling to identify the effects of cytoplasmic substitution on nuclear-cytoplasmic signaling mechanisms.
  
  
  RESULTS
  In combining the wheat nuclear genome with a cytoplasm of H. chilense, 540 genes were significantly altered, whereas 11 and 28 genes were significantly changed in the alloplasmic lines carrying the cytoplasm of Ae. uniaristata or Ae. tauschii, respectively. We identified the RNA maturation-related process as one of the most sensitive to a perturbation of the nuclear-cytoplasmic interaction. Several key components of the ROS chloroplast retrograde signaling, together with the up-regulation of the ROS scavenging system, showed that changes in the chloroplast genome have a direct impact on nuclear-cytoplasmic cross-talk. Remarkably, the H. chilense alloplasmic line down-regulated some genes involved in the determination of cytoplasmic male sterility without expressing the male sterility phenotype. Metabolic profiling showed a comparable response of the central metabolism of the alloplasmic and euplasmic lines to light, while exposing larger metabolite alterations in the H. chilense alloplasmic line as compared with the Aegilops lines, in agreement with the transcriptomic data. Several stress-related metabolites, remarkably raffinose, were altered in content in the H. chilense alloplasmic line when exposed to high light, while amino acids, as well as organic acids were significantly decreased. Alterations in the levels of transcript, related to raffinose, and the photorespiration-related metabolisms were associated with changes in the level of related metabolites.
  
  
  CONCLUSIONS
  The replacement of a wheat cytoplasm with the cytoplasm of a related species affects the nuclear-cytoplasmic cross-talk leading to transcript and metabolite alterations. The extent of these modifications was limited in the alloplasmic lines with Aegilops cytoplasm, and more evident in the alloplasmic line with H. chilense cytoplasm. We consider that, this finding might be linked to the phylogenetic distance of the genomes.
authors: Cristina
authors: C
authors: Crosatti
authors: Lydia
authors: L
authors: Quansah
authors: Caterina
authors: C
authors: Maré
authors: Lorenzo
authors: L
authors: Giusti
authors: Enrica
authors: E
authors: Roncaglia
authors: Sergio G
authors: SG
authors: Atienza
authors: Jacob Blaustein Institutes for Desert Research, French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, 84990 Sde Boqer, Israel. luigi.cattivelli@entecra.it.
authors: Luigi
authors: L
authors: Cattivelli
authors: Aaron
authors: A
authors: Fait
mesh_terms: D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D003593:Cytoplasm / Q000235:genetics* / Q000378:metabolism*; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D055442:Metabolome; D055432:Metabolomics / Q000379:methods; D008928:Mitochondria / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics; D051479:Plant Infertility / Q000235:genetics; D015398:Signal Transduction; D014908:Triticum / Q000235:genetics* / Q000378:metabolism*
chemical_list: D045222:Electron Transport Chain Complex Proteins; D005227:Fatty Acids