Interaction of salicylic acid and cadmium on growth, photosynthetic pigments and ion distrubiution in arial parts of soybean plantlets

In this study, the role of salicylic acid in cadmium induced physiological changes was investigated in solid hydroponic culture in soybean plantlets. After presoaking soybean sterilized seeds in 0.5 mM SA solution for 6 hrs, seeds were transferred to pots containing perlite and then they were irrigated with Hoagland nutrient solution (full strength) containing 200 µM CdCl2 for 20 days. After harvesting the plantlets and calculation of growth parameters (root and shoot dry and fresh weight and length), photosynthetic pigments contents (chl a and b), electrolyte leakage in leaves, and cadmium content (in the roots and the shoots) as well as Ca and K content in shoots, it came to our knowledge that salicylic acid had little effect on this parameters in the absence of cadmium, but in the presence of cadmium, SA increased growth parameters, photosynthetic pigments contents, Ca and K content in shoots, against decreased electrolyte leakage in leaves and cadmium content in arial parts of plant. Therefore, SA could reduce cadmium toxicity and protect growth potential of plant by changing plant strategy in translocation of elements to aerial parts of plant and inhibition of electrolyte leakage and protection of photosynthetic pigments.