Glycine betaine enhancing plant growth and antioxidant activity of fenugreek (Trigonella foenum-graecum L.) under salt stress

Pot experiment was conducted to evaluate the impact of exogenous foliar spray of GB on vegetative growth and some biochemical aspects of fenugreek (Trigonella foenum-graecum L.) in the presence of salt. GB was applied to four concentrations (0, 25, 50, and 75 mM) under salt concentration, 150 mM NaCl in addition to the control. salt stress decreases all the growth parameters and negatively affects photosynthetic pigments as well as relative water content and protein. However, the foliar spray of GB increases these parameters, especially at a concentration of 50 mM. Regarding carbohydrates, total phenolics, flavonoids and antioxidant activity increased under salt stress compared to control also GB foliar spray induced the accumulation of them. Moreover, these parameters increase by increasing the concentration of GB. More than others, GB reduces the entry of deleterious ions (Na+ and Cl-), in contrast, boosts the accumulation of Ca2+ and K+. These results suggest that foliar spray of GB can enhance the growth and tolerance of fenugreek under saline conditions.