Speciation of metals in indigenous plants growing in post-mining areas: Dihydroxynicotianamine identified as the most abundant Cu and Zn ligand in Hypericum laricifolium

Katarzyna Kińska (1) , Edith Cruzado-Tafur (2) , Maroussia Parailloux (1) , Lisard Torró , Ryszard Lobinski (1) , Joanna Szpunar (1)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
2 PUCP - Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru

Ag, As, Cu, Pb and Zn were found to be the principal metallic contaminants of a post-mining area of Peru (Hualgayoc, Cajamarca). Study of metal distribution amongst roots, stems, and leaves of four indigenous hypertolerant plant species, Arenaria digyna, Puya sp., Hypericum laricifolium, Nicotiana thyrsiflora indicated significant translocation of Zn (0.6 < TF ≤ 10.0) and Cu (0.4 < TF ≤ 6.5) into aerial plant organs and substantial water-extractable fraction (20–60%) of these metals, except for A. digyna (root and stems). A study of the metal speciation by ultrahigh-performance size-exclusion (fast-SEC) and hydrophilic ion interaction (HILIC) liquid chromatography with dual ICP (inductively coupled plasma) and electrospray (ESI) Orbitrap MS detection revealed the presence of nicotianamine and deoxymugineic acid copper and zinc complexes in roots, stem and leaves of N. thyrsiflora and Puya sp., and nicotianamine alone in A. digyna. A previously unreported compound, dihydroxy-nicotianamine was identified as the most abundant Cu and Zn ligand in H. laricifolium. The presence of arsenobetaine and an arsenosugar was confirmed by ESI MS. Ag and Pb were hardly translocated to leaves and were found as high molecular species; one of the Pb-containing species co-eluted in fast-SEC-ICP MS with rhamnogalacturonan-II-Pb complex commonly found in in the walls of plants.

Mots clés: Andean flora; Dihydroxynicotianamine; Hyphenated techniques; Low molecular complexes; Metal speciation; Post-mining areas

Domaines: Matériaux; Polymères; Chimie théorique et/ou physique; Chimie analytique

Katarzyna Kińska, Edith Cruzado-Tafur, Maroussia Parailloux, Lisard Torró, Ryszard Lobinski, et al.. Speciation of metals in indigenous plants growing in post-mining areas: Dihydroxynicotianamine identified as the most abundant Cu and Zn ligand in Hypericum laricifolium. Science of the Total Environment, 2021, pp.151090. ⟨10.1016/j.scitotenv.2021.151090⟩. ⟨hal-03418946⟩