The contamination of soil by potentially toxic elements (PTEs) is a problem resulting from various anthropic activities including the exploitation of mines, which determines an accumulation of metal(loid)s in the surrounding area. It is therefore necessary to use remediation techniques to prevent the potential damage to human health and the ecosystem. One of these techniques is phytoremediation, which involves the revegetation of contaminated areas in such a way as to reduce the spread of contaminants and entry into the groundwater by stabilizing the metal(loid)s in the soil, decreasing their mobility. To increase the ability of plants to grow under the extreme conditions of contaminated soils, it is necessary to use amendments, which can also intervene directly in reducing the mobility of contaminants. In this study, an open-field mesocosm was set up using a former mining technosol contaminated mainly by As. A biochar produced from hardwood was added at two different depths to evaluate the effectiveness of these application modalities for an overall observation duration of 17 months. Iron sulphate was also applied in both non-biochar and biochar amended conditions. In addition, trees of Alnus sp. were planted to examine the effectiveness of these plants for their use in soil remediation and the effect of the treatments used. The results showed an increase in soil pH induced by the biochar, which decreased over time. During the period examined, the application of biochar in the deepest layer was able to retain As more effectively. The Alnus sp. showed similar growth rates among the various treatments, resulting from its tolerance towards arsenic.

Common bean landraces, besides contributing to the preservation of the social and cultural identity of the local communities of the production area, typically display adaptability to adverse agro-climatic conditions. This adapted germplasm is a repository of the gene pool and also shows typical phytochemical profiles, representing an essential source of bioactive components. However, genetic erosion is progressively affecting this genetic material, creating serious threats to its cultivation in marginal rural areas and use as a source of biodiversity and bioproducts. In the present work, a comprehensive approach was used to characterize the seed morpho-colorimetric traits, genetic diversity, and NMR metabolomic profiles of three Italian common bean landraces. Specific physiological and biochemical features (antioxidant molecules, osmolytes, structural reorganization of photosynthetic pigment, etc.), together with the accumulation of distinctive metabolites, contribute to the description of the observed diversity among the landraces in terms of the salt stress response and antiproliferative abilities on intestinal human cancer cells. This information could be useful in establishing their value in terms of environmental and/or human health “service”, both essential to translating landraces into competitive products, a prerequisite for envisioning appropriate strategies for their conservation and a driving force for the revitalization of marginal rural areas.

To gain insight into two different plant strategies (hyperaccumulation and phytostabilization) for managing heavy metals, we conducted a network based functional enrichment analysis. Protein-protein interactions of A. halleri root and shoot were derived by weighted gene co-expression analysis. While, in the case of A. thaliana, protein-protein interactions characterizing the organs were derived from STRING database based on genes known to be expressed in root and shoot. Protein-protein interaction clusters of root and shoot networks of both species were analyzed to identify enriched pathways. Thus, we provide a first clear analysis of the biological peculiarities of different organs of both species.

In recent years, the restoration of metal(loid) polluted soils through the combined use of plants-amendments-microorganisms is a strategy that is receiving great attention. However, the molecular processes underlying this synergy are not fully understood. Thus, the aim of this work was to provide insight into the biological mechanisms used by Arabidopsis thaliana to grow in soil contaminated by arsenic and lead and amended with biochar and/or Bacillus sp. inoculum. To accomplish this goal, a pot experiment was set up and the effects of the biochar amendment and the bacterial isolate were evaluated, both alone and in combination. The effects of the plant-biochar-bacteria synergy were assessed on soil physicochemical characteristics, plant growth and ability to stabilize or accumulate metal(loid)s. In addition, a bioinformatics-assisted proteomics approach was used to understand the molecular processes underlying A. thaliana growth in the different tested conditions. Results showed that the use of biochar and/or Bacillus inoculum resulted in improvements in soil properties and plant growth. Bioinformatics-assisted proteomic analysis showed that, on the one hand, the use of biochar alone led to an over-representation of proteins involved in nutrient metabolism providing plants with essential nutrients for growth. However, biochar alone induced plant defense mechanism dysfunction and increased susceptibility to pathogen attack. On the other hand, the use of bacterial inoculation helped plants to grow thanks to the activation of molecular pathways involved in the defense against biotic stress. Only the combined use of biochar and bacteria ensured the correct balance between molecular processes associated with growth and metal(loid) stress response in Arabidopsis plants.