Effect of Exogenous Application of Brassinolide on Growth and Metabolic Activity of Wheat Seedlings under Normal and Salt Stress Conditions

The present study was carried out to show the effect of brassinolide on normal and salt stressed wheat plant. Grains of wheat (Triticum aestivum sakha 93) were divided into four groups: seeds supplemented with 20 ml distilled water (control); seeds treated with NaCl solutions (25, 50, 100, and 200 mM); seeds supplemented with 0.1, 0.5, 1 and 2 mgL-1brassinolide and seeds treated with a combination of 1mg.L-1brassinolide and the mentioned NaCl concentrations. Root and shoot lengths, fresh and dry weights were measured as indicators for growth and biomass assessments while carbohydrates, proteins, amylase and protease were estimated as indicator for metabolic activity. Treatment of wheat seeds with different concentrations of brassinolide particularly 1mgL-1 causes a significant increase in growth parameters, carbohydrate fractions, total soluble proteins in root and shoot and the hydrolytic enzymes amylase and protease. Gradual increase in NaCl concentrations from 25mM to 200mM sharply decreased growth compared with the control. Results of this investigation showed that 1mgL-1brassinolide counteracted the inhibitory effects of salinity.