Alpha-tocopherol reinforce selenium efficiency to ameliorates salt stress in maize plants through carbon metabolism, enhanced photosynthetic pigments and ion uptake

Abstract

Individually selenium and α-tocopherol showed a pivotal role in combating abiotic stresses in plants. However, there is no report on how selenium behaves in the presence or absence of α-tocopherol under salt stress in crop plants. With this view, the present study was undertaken to dissect the interaction between selenium and α-tocopherol on growth performance, carbon metabolism, and uptake of different ions in maize plants grown under salt stress. This study was conducted with surface-sterilized seeds of maize that were soaked in deionized water (control), selenium (0.5 µM), and/or α-tocopherol (200 ppm) for 12 h before sowing and different salt levels (0, 100, 150, and 200 mM) in the form of NaCl was created in soil. A sample of maize plants from each treatment was collected 40 days after sowing. The results revealed that salinity lowered the growth performance, chlorophyll content, insoluble sugar, carbohydrate, phenolic, flavonoid content, and different ions uptake in concentration dependent manner whereas, soluble sugar, α-amylase activity, and sodium ion increased in comparison to control plants. Moreover, selenium and/or α-tocopherol treated plants without stress significantly amplified the growth performance, chlorophyll and carotenoid content, carbohydrate, phenolic, and flavonoid content, and improved the uptake of different concentrations ions (K+, Ca+2, K+/Na+, Ca+2/Na+, and Mg+2) over the control plants. Interestingly, treatment of combined selenium and α-tocopherol to the salt-stressed plants successfully recover the loss caused by increasing salt levels in maize plants through altered carbon metabolism and ions uptake reflected in improved growth performance and bigger growth leaf area of maize plants under salt stress. Selenium and α-tocopherol in combination also enhance the antioxidative defensive mechanism through the production of phenolics and flavonoids content in maize plants under salt stress. This approach could be an effective measure to lower salt stress and enhance the crop productivity of maize plants.