Comparative analyses of heavy metal responses in Arabidopsis thaliana and hypertolerant facultative metallophyte Arabidopsis halleri

The contamination of soil with heavy metals (HMs) due to anthropogenic activities such as mining, agricultural practices, and industrial operations poses significant environmental challenges. This thesis explores the comparative responses to heavy metal stress in two plant species: Arabidopsis thaliana, a model organism for phytostabilization, and Arabidopsis halleri, known for its hyperaccumulation capabilities. The first part of the thesis comprises comprehensive reviews of arsenic (As) and lead (Pb) toxicity and tolerance in plants, exploring recent advancements in omics technologies. These comprehensive studies highlight significant discoveries in genomics, transcriptomics, proteomics, and metabolomics that have identified key genes, proteins, and metabolites involved in the response to heavy metal stress. The findings highlight the importance of understanding molecular mechanisms to develop plants with enhanced tolerance and phytoremediation capabilities. The experimental section of the thesis focuses on practical applications and detailed molecular analyses. In a study examining the effects of soil amendments, combined applications of 6% biochar and 80% compost were found to significantly enhance soil properties, improve plant growth and metal uptake, thus selected for the subsequent proteomic analysis. Comparative proteomic profiling of these species revealed the distinct mechanisms of A. thaliana and A. halleri to support metal tolerance and accumulation. Furthermore, the identification of key proteins possibly involved in heavy metal stress responses, offering valuable insights into the molecular mechanisms underpinning hyperaccumulation and phytostabilization. Overall, this thesis advances our understanding of the molecular basis of heavy metal responses, providing a foundation for the development of effective and sustainable strategies to remediate contaminated soils. The integration of omics technologies and biotechnological interventions promises to enhance the efficiency of phytoremediation, contributing to environmental sustainability and agricultural resilience.