Characterisation of natural populations of arabidopsis thaliana differing in tolerance to carbonate soil

• Autores: Joana Terés Gelabert
• Directores de la Tesis: Charlotte Poschenrieder (dir. tes.), David Salt (codir. tes.), Roser Tolrà Pérez (codir. tes.)
• Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2017
• Idioma: español
• Tribunal Calificador de la Tesis: Juan Barceló Coll (presid.), Maria Anunciacion Abadia Bayona (secret.), Mark G. M. Aarts (voc.)
• Programa de doctorado: Programa de Doctorado en Biología y Biotecnología Vegetal por la Universidad Autónoma de Barcelona
• Materias:
  • Ciencias de la vida
    • Biología vegetal (botánica)
      • Fisiología vegetal
• Enlaces
  • Tesis en acceso abierto en:  TESEO  TDX 
• Resumen

  • Abstract Natural populations of Arabidopsis thaliana from Catalonia were investigated to identify mechanisms of local adaptation to carbonate soils. After characterizing the chemical properties of the native soils of multiple small stands of A. thaliana (called “demes”), multi-year common garden experiments, based on contrasting soil carbonate levels, were performed to identify differential fitness among demes. Progenies from these demes performed better on control soil without carbonate. However, fitness differences among demes on carbonate soils were associated with the percentage of CaCO3 in the native soils. This confirms that the soil carbonate level is a driving factor for local adaptation.

    Contrasting demes A1 (moderately tolerant) and T6 (sensitive) were selected for analyzing physiological traits. When growing either with carbonate or under iron deficiency both demes differed in chlorophyll content, SOD activity, and the profile of phenolic compounds in root exudates.

    Tolerant deme A1 has the AtFPN2 allele like the reference genotype Col.0. Contrastingly, in sensitive deme T6 the allele sequence is as in Ts-1. The presence of the weak allele of AtFPN2 of Ts-1 could justify the higher accumulation of divalent metals in the leaf of deme T6.

    Crosses between tolerant and sensitive demes revealed heritability of these traits. In F3, tolerant and sensitive families were selected for bulk segregation analysis, which is still under progress.

    For further identifying candidate genes for adaptation to carbonate soil, a Hap-Map collection from NASK was used. Different accessions were grown in carbonate and control soils. Growth and shoot ionome was compared to plants growing on non-carbonate soil. Genome wide association analysis (GWAS) provided a list of genes potentially related with plant tolerance to carbonate soils.

    In conclusion, our results demonstrate that A. thaliana plants naturally adapted to soil with moderate-low carbonate concentrations are more carbonate tolerant than plants from soils without carbonate. This tolerance is inheritable and GWAS revealed multiple candidate genes responsible for tolerance to carbonate soil. BSA-seq results will provide further useful information for the identification of the key genes involved.