Epibrassinolide seed priming alleviates alkaline stress by enhancing antioxidant defense in dragonhead plants

Abstract Alkaline stress is one of the most important environmental factors limiting the production of crops. The current research was conducted in a completely randomized design to investigate the alleviative role of 24-epibrassinolide (24-EBR) seed priming on biochemical and physiological parameters of Lallemantia iberica Spp plant under 48 h of simulation with 15 mM Na2CO3 (pH = 10.84). The 24-EBR significantly moderated the harmful effects of high pH imposition through diminishing the generation of MDA (43% and 55%), H2O2 (51% and 68%), proline (41% and 22%), and soluble sugar (31% and 39%) contents in leaves and roots, respectively. The hormonal presoaking also led to the higher activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and phenylalanine ammonia-lyase (PAL) under exposure to alkaline stress. The findings provide evidence of 24-EBR as a versatile and valuable tool to improve plant resilience against alkaline stress due to the neutralization of oxygen-free radicals and improvement of antioxidant status. The study also shares information regarding biochemical insights to improve soil alkaline stress tolerance in dragonhead plants by alleviating ROS accumulation damage.