Abstract

Barley (Hordeum vulgare) is highly consumed due to energetic and nutritional content. However, the acidic conditions of soils and the presence of toxic aluminum (Al) are important growth-limiting factors for barley plants. It has been demonstrated that silicon (Si) attenuates Al phytotoxicity, as well as it promotes the production of phenolic compounds with antioxidant or structural (e.g. lignin) function. The aim of this research was to evaluate Si and Al uptake, phenols concentration and antioxidant capacity of barley plants cultivated under Al stress conditions. A hydroponic experiment was conducted by using two barley cultivars (Scarlet and Sebastian), which were treated with Al (0 or 0.2 mM Al) and Si (0 or 2 mM) at different harvest times (2, 4, 8, 12, 24, 48 hours). At harvest, Si and Al concentration, total phenols, lipid peroxidation and lignin accumulation were determined in plants. The concentrations of Si and Al increased for the two cultivars when 2 mM Si or 0.2 mM Al was applied, respectively. Aluminium concentration decreased at all harvest times when Al was supplied in combination with Si. The highest concentration of soluble phenols was found at 2 mM Si and 0.2 mM Al addition after 8 hours in both cultivars. Lipid peroxidation decreased in Si-treated plants at all harvest times compared with non-treated plants. Finally, increased lignin accumulation was found when Si was applied in combination with Al. Acknowledgements: FONDECYT Project 1161326 And Dirección De Investigación De La Universidad De La Frontera.