Effect of Salicylic Acid on the Growth, Photosynthesis and Carbohydrate Metabolism in Salt Stressed Maize Plants

The effect of 10 M salicylic acid (SA) on the counteracting of the NaCl (50, 100 and 150 mM)-induced deleterious effects on maize (Zea mays L.) cultivar was studied. Effects of SA on salt tolerance of maize were determined by measuring the growth parameters: shoot and root lengths, shoot and root fresh and dry weights and leaf area. The activity of ribulose 1,5bisphosphate carboxylase (Rubisco), photosynthetic pigments (chlorophylls a, b and carotenoids) content, the rate of CO2fixation and sugars level were investigated in response to the interactive effects of SA and NaCl treatment. NaCl significantly reduced all growth parameters measured, Rubisco activity, photosynthetic efficiency and pigments, as well as sugar contents. The effects of NaCl on the previous parameters were increased with NaCl concentrations. Exogenous application (foliar spray) of SA counteracted the NaCl deleterious effects on maize cultivar. SA enhanced the maize salt tolerance in terms of improving the measured plant growth criteria. SA appears to stimulate maize salt tolerance by activating the photosynthetic process.