PRIMING EFFECT ON BROCCOLI (Brassica oleracea var. italica) SEEDLINGS WITH SELENIUM AND IODINE: ACTIVATION OF BIOCHEMICAL MECHANISMS TO MITIGATE COLD STRESS
Selenium and iodine combination, enzymatic antioxidant system, osmoprotectants, oxidative stress, beneficial elements
The present research work focused on the study of the biochemical adaptation mechanisms of broccoli cultivar Avenger when exposed to low temperatures (2ºC). The objective of this work was to investigate the priming effect of various doses of Se and I on broccoli seedlings exposed to low temperatures to improve physiological defense mechanisms. In this way, it was intended to explain the defense mechanisms activated in this crop at the seedling stage by the application of Se, I and the interaction of Se+I when exposed to stress. Because, it is in the initial stages where the crop is more prone to suffer some kind of damage, compared to a fully developed plant. Since it has not yet fully developed and lacks the mechanisms to protect itself from stress. This work was conducted in the greenhouse at the Federal University of Lavras and then the plants were transferred to a phytotron to simulate stress conditions for three days. Selenium and I were applied before stress at different doses. The leaves were then collected in liquid nitrogen and biochemical analyses were performed at the Laboratory of Physiology of Cultivated Plants of the Department of Biology (DBI)-UFLA. Biochemical analyses of the osmoprotectant content and the enzymatic antioxidant system were performed to try to explain how the broccoli crop acted to reduce lipid peroxidation through the quantification of MDA. Finally, the results indicated that indeed the application of Se, I and Se+I managed to visually decrease leaf damage and this is explained by the bitplots of the Principal Component Analysis (PCA).