Effect of exogenous salicylic acid on manganese toxicity, mineral nutrients translocation and antioxidative system in polish wheat (Triticum polonicum L.)

The present study investigated the morphological and physiological effect of salicylic acid (SA) on manganese toxicity in dwarf polish wheat (Triticum polonicum L.) seedlings grown hydroponically. Our findings showed that Mn stress could decrease plant growth, cause serious chlorosis and injury the photosynthetic apparatus. An increase of Mn accumulation and the inhibition of the K and Ca absorption and the Mg, Fe and Zn translocation were observed under Mn stress. Also, there was a considerable increase in H2O2 and TBARS (thiobarbituric acid-reactive substances) content in both the roots and leaves under Mn condition. The combination of SA and Mn treatment decreased the transport of Mn, Fe and Zn from roots to shoots and increased the Ca absorption and Mg translocation. In antioxidant system, such as CAT, APX, GR, DHAR, GSH and AsA, the combined treatment significantly increased the antioxidant content and antioxidative enzyme activities compared to the Mn stress alone. The level of ROS and lipid peroxidation significantly decreased under the combination of SA and Mn. These results suggested that SA-induced Mn tolerances in polish wheat are mainly by inhibiting Mn translocation, enhancing enzymatic activities and nonenzymatic antioxidants contents, and regulating nutrient absorption and distribution in plants.