Alleviating Effect of Salicylic Acid on the Cadmium Toxicity in Lettuce Seed Germination

Cadmium(Cd)was a highly toxic and persistent environmental poison,its increasing level in soil environment exerted a wild range of adverse effects on plants and even the healthy of human beings by food chains.Salicylic acid(SA),considered as a hormone-like substance,played an important role in modulation of acclimation responses for plant.The possible effects of SA on lettuce seeds germination and seedlings growth under Cd stress were studied.The results showed that the quality of seed germination and seedling growth were significantly inhibited under Cd stress,especially for root length,vigor index,etc.Moreover,Cd stress could lead to oxide stress and high level of lipid peroxidation.Different concentrations of SA had different roles on seed germination and seedling growth under Cd stress and low concentrations of SA could enhance the germination and seedlings growth,however,high concentration had a inhibition effect.Our results showed the protection role of 0.1 mmol/L SA was best for seed germination and seedling growth,respectively.Alleviating the cadmium toxicity in seed germination and seedling growth by SA was due to modulating the activities of CAT,APX,SOD and GPX.