Phytostabilization potential and tolerance mechanisms of native species from the Pampa biome in vineyard soil with high levels of Cu, Zn and Mn.

Fungicides applied to grapevines can increase the levels of copper (Cu), zinc (Zn), and manganese (Mn) in soils and cause phytotoxicity to plants. However, plants native to the Pampa biome might have the potential to phytostabilize these metals. The study aimed to (a) verify whether higher levels of Cu, Zn, and Mn in the soil increase the concentrations of these elements in different organs of the native species; (b) determine which variable is most directly associated with biomass variation in the evaluated species; and (c) identify the tolerance mechanisms used by these species to tolerate high levels of Cu, Zn, and Mn in the soil, as well as their phytostabilization potential. To this end, three native species, Axonopus compressus, Paspalum notatum, and Paspalum plicatulum, were grown in vineyard soil and native field soil. The cell wall and vacuole played an important role in detoxifying the metals. The concentrations of photosynthetic pigments were lower in the A. compressus and P. notatum species grown in the vineyard soil. Metals caused oxidative stress in roots, and the activities of the antioxidant enzymes SOD and POD increased in leaves and roots. The three species showed the lowest dry mass yields in the aerial part. The species P. notatum and P. plicatulum are the most suitable to be used for the phytostabilization of Cu, Zn, and Mn in vineyards in the Pampa biome.