Effect of Silicon on the Peroxidase Gene Expression and Morphological Traits of Barley Under Drought Stress

Aim: The purpose of the present research project was evaluation of the effect of silicon on the severity of peroxidase genes expression and some morphological traits in both resistant and susceptible barley lines under drought stress.
Material and Total soluble protein content, photosynthetic pigments, and total RNA were extracted from the leaves affected by various treatments. Target gene was evaluated by Semi-quantitative RT-PCR analysis using synthesized cDNA. Both the peroxidase enzyme activity by Chance method and proline with Bates method were also evaluated under drought stress treatment. Accordingly, the experiment was analyzed in a factorial test based on the completely randomized design with three treatments of control, drought and silicon-drought (sodium silicate 2 mg / 1 Kg soil) with three replications in a greenhouse.
Silicon application caused to increase the amount of total soluble protein and photosynthetic pigments in both lines under drought stress. Semi-quantitative RT-PCR analysis of treatments observed significant differences. Maximum of peroxidase gene expression was observed in the silicon-drought treatment. Antioxidant enzyme activities were at the highest level as shown by gene expression pattern of polyacrylamide gel analysis for treated silicon samples. A further increase was exhibited for proline accumulation caused by silicon application rather than such accumulation in stress treatment compared to control.
Silicon reduces oxidative damage induced by reactive oxygen species and with the increase in antioxidant enzyme activities caused to protect plants against environmental stresses.