Effects of foliar application with salicylic acid on the biochemical parameters and redox status in two Canola plant varieties exposed to cold stress
By: Zoheir Mellouk, Ilhem Benammar, Yvan Hernandez
Key Words: Antioxidant enzymes, Cold stress, Oxidative damage, Photosynthetic Pigments, Salicylic acid.
Int. J. Agr. Agri. Res. 8(5), 77-87, May 2016.
Low temperature is an important environmental factor that limits the survival, productivity and geographical distribution of plants. Oil seeds are the second global food resources among which Brassica napus L. is the third annual oil seed in the world. In cold stress, some biochemical and physiological reactions occur in response to reactive oxygen species (ROS). Hence, the effect of foliar application of salicylic acid (SA) on total chlorophyll content, malondialdehyde, and antioxidant enzymes activity and solute protein and proline contents were assessed in two canola varieties (Brassica napus L., cv RGS and LICORD) leaves exposed to cold stress during 0, 24, and 48 hours after salicylic acid treatment. They were first grown in a controlled growth room at 22/20 °C (day/night) for one month followed by SA spraying application (100, 200 and 400µM) and then plots were transferred to a cold environment (-2 °C) for 3 days. The results showed that the total chlorophyll content was decreased in RGS cultivars related to high salicylic acid concentration during the experiment. The results of antioxidant status showed that superoxide dismutase (SOD), peroxidase (POX), and also lipid peroxidation were increased significantly after 48 hours compared first day. Catalase (CAT) activity was decreased 24 hours after salicylic acid treatment. Results showed an increase in protein content in both cultivars treated with SA, by contrast proline was greatly affected by salicylic acid treatment and its content was the highest 24 hours after treatment. According to the results of the present study indicated that application of salicylic acid has useful effects on the biochemical traits. Thereupon it may be effective for the improvement of plant growth in cold regions.