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Anthropic activities such as industries, agriculture and mining has generated public concern for its numerous irregular disposals of its waste, the incorrect deposition of heavy metals such as nickel (Ni) has caused the degradation and contamination of groundwater and water. Studies that point out cheap and efficient solutions have been an obstacle to the advancement of solutions for degraded area recovery programs. For this, a vegetable home experiment was developed, with an entirely randomized design with 5 treatments being a control (no metal) and 4 nickel concentrations (200 μM/L; 400 μM/L; 600 μM/L and 800 μM/L) with 6 repetitions. The variables analyzed were growth and biochemical activity. Plant height and diameter were not affected by increasing nickel concentrations and this response was due to the low leaf and leaflet production capacity of the species under these conditions, consequently reducing biomass production. Metabolic parameters such as sucrose, carbohydrates, proline and glycine increase under stressful conditions, which does not occur for nutritional configurations that decrease with increasing nickel stress.

The advancement and intensification of industrial and mining activities has generated a series of impacts on natural ecosystems, combined with the inappropriate use of agrochemicals and the erroneous disposal of electronic products, contributing to soil contamination with a diversity of chemical elements, including heavy metals. Due to this, this work aimed to evaluate the effect of increasing dosages of nickel on the anatomy, biochemistry and oxidative system of Brazilian mahogany (Swietenia macrophylla), a forest species from the Amazon, seeking to indicate the potential use of this species in phytoremediation programs. of soils contaminated with heavy metals. The seeds were grown under a constant temperature of 28°C, relative humidity (RH) of 90% with a 12-hour photoperiod for 43 days. The experimental design used was randomized blocks (DBC), with five treatments (0, 2, 4, 6 and 8 mg.L-1 of Nickel), with six replications. Data were subjected to analysis of variance (ANOVA) and means were tested for significant differences using the Tukey test at 5% significance. Changes in the anatomy of the different organs were observed, with differences in the cells in the central region of the leaf, the stem and the root. The concentration of total carbohydrates had no statistical differences with the application of nickel, however changes were observed in photosynthetic pigments, reducing sugars and sucrose as an adaptive form to nickel. The increase in nickel dosages was accompanied by the synthesis of ammonium, amino acids and proline in the root, while the synthesis of glycine was reduced. In the leaf, there was an increase in amino acids with an increase in metal, accompanied by a decrease in glycine. The plant antioxidant defense system was efficient in attenuating the toxic effects of ROS, with significant actions of CAT and SOD enzymes in the root, while the leaf had the main action of APX and CAT. The cultivation of mahogany plants can be advocated to mitigate Ni pollution in these areas, as this forest species has a particular characteristic of resistance to stressful conditions in contact with the heavy metal.