Native plants as stabilisers agents for lead-contaminated environments.

MENOYO E., SALAZAR M.J., BECERRA A.G.

Congreso; XLII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2024

Pollutants can cause irreversible changes in the environment and controlling their dispersion is essential to avoid further damage. In particular, heavy metal (HM) contamination causes changes in the organisms that inhabit these areas. The study of these communities can be valuable in understanding how they survive in such environments. The objective of this work was to analyze HM accumulation and mycorrhizal associations in the dominant plant species present in lead (Pb) contaminated sites. The study area is located in Bouwer, Córdoba, where a battery recycling plant contaminated the surrounding sites with Pb. Seven sites with different Pb soil contents were selected; site I: 15μg.g-1, site II: 341μg.g-1, site III: 374μg.g-1, site IV: 248μg.g-1, site V: 979μg.g-1, site VI: 22660μg.g-1, site VII: 17198μg.g-1. In each site, 5 individuals of the most abundant plant were collected. The concentration of Pb in the shoot and root was determined by the total reflection of X-ray fluorescence. The accumulation (BCF: bioconcentration factor shoot/soil) and the translocation capacity of Pb (TF: translocation factor shoot/root) were calculated. Mycorrhizal associations were determined and quantified under the microscope. Bidens pilosa, Jarava aff. ichu, Solanum argentinum and Zinnia peruviana accumulated Pb in the root. Metal translocation capacity was low, and differences were observed between plants and sites. Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) were registered in the roots of all study plants. The proportion of fungal colonization varied between the host plants and the sites.In general, B. pilosa and Z. peruviana presented the highest AM colonization and lowest DSE colonization while in S. argentinum and J. ichu the proportion of fungal colonization was similar. According to the plant species, a positive relationship between Pb soil, Pb roots and fungal colonization was detected. These plant/AMF/DSE associations would allow the development of strategies to survive in these environments, including immobilization of the metal in the root system. Considering these strategies in the stabilization of lead-contaminated soils could be essential for the advance of environmental bioremediation practices.