Avaliação dos genes CYP85A2, BZR1 e CAD1 na atenuação de cádmio em mudas da espécie Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby (Paricá) em diferentes concentrações de 24-epibrassinolídeo.

Abstract

The Amazonian species paricá (Schizolobium parahyba var. amazonicum (Huber ex Ducke) Bar-neby), native to the Amazon, demonstrates bioaccumulation characteristics related to cadmium (Cd) ions. However, the lack of understanding of gene modulation in responses to interactions between Cd and phytohormonal mechanisms, which act in different parts of the plant, such as leaves and roots, represents a challenge in understanding its role and relevance in the ecological context. the rehabilitation of degraded areas. Therefore, the present study seeks to examine the expression of the CYP85A2 and BZR1 genes, precursors of endogenous 24-EBL, in the production of chelating proteins by the CAD1 gene in seedlings of the Paricá species, under different concentrations of CdCl2 and 24-EBL. The experiment was conducted in an air-conditioned growth room at the Higher Plant Biodiversity Studies Laboratory (EBPS), Universidade Federal Rural da Amazônia (UFRA), Campus-Belém-Pará, following a completely randomized experimental design (DIC), in a factorial scheme. 4x3, totaling 60 ex-perimental units containing 15 seeds per replication, 4 treatments of CdCl2 (0, 50, 100 and 150µM) and the other three consisted of different doses of 24-epibrassinolide (0, 20 and 40 nM). The data were subjected to ANOVA analysis of variance (p < 0.05) and the differences between treatments analyzed using the Tukey test (p < 0.05). Biometric variables demonstrat-ed an intense reduction in root length due to the harmful effect of CdCl2 on the substrate. Furthermore, there were losses in Chl a, Chl b and Chl a+b due to the entry of Cd2+ into the leaf tissues. Despite this reality, the relative expression levels of the CYP85A2, BZR1 and CAD1 genes were significantly higher in the aerial part at different doses of 24-EBL (0, 20 and 40 nM), compared to the root system. Likewise, a change in CAR and ACN levels was noted as a result of the increase in CdCl2. These findings suggest greater genetic adjustment in the upper part of plants, potentially increasing their biological functions by facilitating energy metabolism and maintaining cell structuring to combat Cd toxicity.