Role of silicon foliar application in promoting salt stress tolerance and enhanced antioxidant capacity of Hordeum vulgare L. (cv. saida)
Abstract
A. Alayat*, Z. Boumedris, S. Benosmane, A. Atailia, O. Moumeni and N. Hacini
Barley production under salinity stress is a critical challenge facing many countries, particularly those in arid and semi-arid regions. Various methods were used for inducing salinity tolerance including application of stress tolerance-inducing substances. Silicon (Si) supplementation is considered one of the promising methods to improve plant resilience under salt stress. The aim of this study was to determine the imperative roles of silicon foliar application methods, in improving growth, malondialdehyde (MDA) superoxide (O2·-) and hydrogen peroxide (H2O2) contents and activating antioxidant system of salt affected barley plants. For this purpose, we investigated the effects of salinity (NaCl; 100 mM) stress on barley seedlings (Hordeum vulgare cv. saida) during silicon (Si; 1 mM and 2 mM) applications. The results showed that salinity had deleterious effects on plant growth. Salt-stressed plant shoots exhibited a greater activity of ascorbate peroxidase (APX), peroxidase (POD), but a lower activity of catalase (CAT) when compared to the control. Conversely, exogenous application of Si by spraying leaves led to improvements vegetative growth and caused significant increases in antioxidant defense systems of barley seedlings. Furthermore, lipid peroxidation, levels of superoxide, and hydrogen peroxide were decreased with silicon treatments. This results provides evidence of the positive influence of Si on alleviating the toxicity of NaCl in barley plants and can be further extended for field trials in salinity affected areas.