Comportamento bioquímico em mudas de castanheira-do-brasil (Berthollethia excelsa Bonpl.) Submetidas a diferentes concentrações de alumínio

Abstract

Most Brazilian soils have acidic characteristics, and one of the elements present in this soil is aluminum, which is toxic to plants, affecting the metabolism of several species. Faced with the problems limiting the phytotoxicity of aluminum to vegetables, this study aimed to investigate the biochemical behavior in seedlings of Berthollethia excelsa Bonpl. subjected to different concentrations of aluminum. The experiment was conducted in a greenhouse using a completely randomized design with five treatments (0 mg L-1, 20 mg L-1, 40 mg L-¹, 60 mg L-1 and 80 mg L-¹ of Alt3+) and seven replicates. The analyzed variables were photosynthetic pigments, nitrate reductase, electrolyte leakage, nitrate, free ammonium, N-aminosoluble, soluble proteins, total soluble sugars, reducing and non-reducing sugars, sucrose, proline and glycine betaine. According to the results, photosynthetic pigments, nitrate, nitrate reductase, ammonium, N-aminosoluble, total soluble sugars, reducing and non-reducing sugars and sucrose reduced with the highest concentration of aluminum in the medium. Electrolyte leakage showed increase as well as soluble proteins, and the osmoregulators, proline and glycine betaine, showed increases suggesting the attenuation of the stress caused by the toxicity of this metal. Despite the negative influence on the biochemical processes, brazilian chestnut, presented mechanisms of tolerance to aluminum toxicity, maintaining the biochemical activities for the vegetative development.