The Effect of Sunflower Seed Priming in Reducing Drought Stress on Antioxidant and Morphological Characteristics During the Germination Stage

Abstract Drought poses a significant risk to the cultivation of drought-sensitive crops. Consequently, it is essential to employ management strategies to mitigate the impacts of drought. Four levels of PEG (0.0, − 0.40, − 0.80, and − 1.20 MPa) and four levels of glycine betaine (GB) and gibberellic acid (0, 15, 30, and 45 mg/l) were used in a factorial form with a completely random design over three repetitions in order to assess the impact of treating sunflower seeds with these substances under experimental drought stress conditions. After soaking the seeds for 12 h in the aforementioned glycine betaine and gibberellic acid concentrations, the seeds were transferred to a Petri dish and mixed with the prepared concentrations of polyethylene glycol 6000 to be applied to every dry surface. The findings indicated that drought stress resulted in a substantial reduction in all assessed parameters across the control group and various amounts of glycine betaine and gibberellic acid. Seeds primed with glycine betaine exhibited a substantial enhancement in germination rate and power, root length, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and lipid peroxidation (MDA). 30 mg/l dosage of glycine betaine demonstrated superior efficacy in improving the protective response to stress. The PCA analysis revealed that the parameters examined could be classified into two separate categories. Consequently, glycine betaine may be regarded as a natural and environmentally benign agent for augmenting plant resilience to drought stress.