Avaliação nutricional de mudas de Tento carolina (Adenanthera pavonina L.) submetidas a diferentes concentrações de cádmio e brassinosteroide.

Abstract

Adenanthera pavonina L. is a pioneer species belonging to the Fabaceae family. It is fast-growing, has dark, compact wood and is used in luxury carpentry and reforestation, as well as having ornamental and fodder characteristics. Cadmium (Cd2+) is a non-essential element for plants, causing toxicity even in small concentrations. However, brassinosteroids are proving to be a viable solution to Cd contamination in plants, as they have the potential to provide tolerance to biotic and abiotic stresses. The aim of this study was to evaluate the nutritional status of young A. pavonina L. plants subjected to different concentrations of cadmium and 24-epibrassinolide and to examine how the heavy metal and the hormone affect the nutrient status of N, P, K, Mg and Ca in leaves and roots. The experiment was completely randomized in a 3x2 factorial design, with three cadmium levels (0, 15 and 30 mg/L Cd) and two concentrations of 24-epibrassinolide (0, 100 nM EBR). There were five replicates in each of the six treatments, totaling 30 experimental units, with one plant in each unit. Cd2+ generally decreased the concentrations of all the nutrients in both parts of the plant (roots and leaves). It was found that the EBR was able to briefly mitigate the levels of metal toxicity, possibly through the absorption and regulation of ions in the cells.