Speaker
Description
All ecosystems on land rely on plants to manage nutrient balancing in soils containing variable and largely non-optimal bioavailable levels of essential and non-essential inorganic compounds. Our research aims to understand the molecular and physiological mechanisms of the underlying physiological acclimations and evolutionary adaptations in plants. Arabidopsis halleri is a characteristic member of metallophyte plant communities found on soils containing toxic levels of the heavy metals zinc, cadmium, lead, and sometimes copper. In both polluted and pristine unpolluted habitats, natural populations of A. halleri are unusual in their ability to hyperaccumulate zinc and cadmium in their above-ground tissues at concentrations that are one or more orders of magnitude above the critical toxicity thresholds of ordinary plants. We confirmed exceptionally large edaphic and ionomic ranges across European A. halleri based on a biodiversity resource of ca. 1,000 accessions collected in the field. These A. halleri individuals are edaphically and ionomically indexed, meaning that the elemental composition of leaves and rhizosphere soil is known for each genotype at its site of origin. We address natural variation within A. halleri and compare across species with the closely related well-studied reference organism A. thaliana, a non-accumulator species exhibiting merely basal heavy metal tolerance which is common to all plants. We conducted genome-wide association mapping using our A. halleri collection, and we also mapped quantitative trait loci in segregating populations of targeted crosses between phenotypically contrasting individuals. I will present exemplary results highlighting the gap of knowledge between the molecular-cellular functions of decisive protein variants and associated phenotypes at the whole-plant level, which could be bridged through the localized quantification of metals and their chemical speciation. Our results can educate the improvement of crop safety and the development of plant-based technologies such as phytomining and phytoremediation.