In vitro and in silico study of salt stress resilience in Brassica rapa through selenium seed priming

Horticultural crops are usually very susceptible to salinity stress during germination and plant growth. The current research work describes the potential of selenium (Se), an antioxidative element to alleviate salinity stress in Brassica rapa. For this purpose, 50,75 and 100mmolL-1 Na2SeO4 were used as seed priming solutions. Effects of Na2SeO4 seed priming were observed on the growth, stress biomarkers, mineral nutrition, and antioxidative defense machinery of B. rapa var. purple top white globe subjected to 200 mM sodium chloride (NaCl) stress. Salt toxicity reduced root growth, shoot growth, biomass production, chlorophyll content, nutrition, and gas exchange parameters in seedlings. Moreover, NaCl-induced oxidative injury enhanced the biosynthesis of hydrogen peroxide and lipid peroxidation in treated plants. Conversely, Se-2 treatment alleviated NaCl stress by modulating the biosynthesis of total soluble sugar, and proline, and improving the activity of antioxidative enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD) and catalase (CAT). Likewise, changes in the expression level of CAT, POD, SOD, and APX genes augmented ROS scavenging capacity in Se-treated plants. Additionally, Se treatment diminished Na+ content and enhanced Se content responsive for the higher defensive role in the treated seedlings. The in-silico data obtained through molecular docking of Na2SeO4, NaCl, and antioxidant macromolecules cytochrome P450 (CYP), lipoxygenase (LOX), and xanthine oxidase (XO) also confirmed the salt stress ameliorative potential of Se in B. rapa. Invitro and in silico results demonstrated that seed priming with optimum Se-2 concentration effectively mitigates salt toxicity and improves the growth and nutrition of B. rapa plants. The findings of the present study provide integration of conventional physiochemical and molecular techniques besides a novel computational modelling system to assess salt stress ameliorative efficacy of Se seed priming in B. rapa plants seedlings.