Potential use of Ecdysone in protecting wheat ( Triticum aestivum) germination under cadmium stress

The purpose of this work is to explore the potential of Ecdysone (Ecd) in protecting wheat seedlings from the toxic effects of cadmium (Cd). Various growth parameters such as germination, tolerance index, plant biomass, and vigor index were assessed. Additionally, germination metabolic parameters including soluble sugar content, soluble proteins, free amino acids, amylase, and protease activities were measured. During this study, we investigated the stress markers content, proline, chlorophyll, and antioxidant enzymes. The amount of Cd uptake and its distribution at the cellular level were evaluated. In the absence of pretreatment. The results showed that high concentrations of Cd (0.1 and 0.5 mM) caused a decrease in germination (13%-35%) and growth (24%-53%). In addition, indicators of oxidative stress were observed, suggesting an alteration of physiological processes. Key germination enzymes alpha-amylase and proteases activities decreased with increasing Cd concentration, leading to a reduction in solubles sugar (48%-64%) and amino acid (55%-64%) levels. Ecdysone pretreatment (10 mu M) significantly mitigated Cd toxicity in young plants by decreasing its absorption (71%-40% in leaf and root respectively at 0.5 mM Cd), alleviating oxidative stress (36%-43% reducing MDA), and enhancing detoxification processes. In addition, Ecd pretreatment maintained normal germination, tolerance, biomass, and metabolism in the presence of Cd. According to our results, Ecdysone ensures the preservation of oxidative balance and promotes wheat germination metabolism.