SILICON ENHANCES THE SALT TOLERANCE OF TWO WHEAT CULTIVARS THROUGH DECREASING OXIDATIVE DAMAGE

Abstract

Using two wheat (Triticum durum) cultivars (cvs. Vitron and Simeto) hydroponic solution experiments were conducted in order to study the genotypic variation in tolerance to NaCl toxicity and to investigate effect of silicon supplied to the nutrient solution on wheat plants grown at salt stress. The experiment was a 2×2 factorial arrangement with two levels of NaCl in nutrient solution, 0 and 100 mM, and two levels of silicon (Si) in nutrient solution, 1 and 2 mM, as Na₂SiO₃.9H₂O. Silicon supplementation has an important role in alleviating salinity injury, however, the definite mechanisms stay scantily understood, and must be examined. The role of silicon application in improving growth, maintaining water status and alleviating oxidative injury of salt affected wheat plants were studied. Indeed, our results indicate salinity induced in wheat plants a notable increase in oxidative biomarkers, reduced plant growth and produced less dry matter content than those without NaCl. However, the reductions of seedling height, dry biomass, and soluble content were greatly alleviated due to Si addition to the culture solution. Thus, the beneficial effects of Si on oxidative biomarkers contents under NaCl stress were genotype-dependent. The beneficial effect of Si on alleviating oxidative stress was much more pronounced in Vitron (salt tolerant cultivar) than in Simeto (salt sensitive cultivar).