Effect of salinity on the growth and peroxidase and IAA oxidase activities in canola

An experiment was conducted to find the effect of NaCl salinity on the growth and antioxidant activities in canola (Brassica napus L. cv SLM 046 ). Treatments consisted of three levels of NaCl (0, 100 and 200 mM). The experiment was arranged in a completely randomized block with four replications. Vegetative characteristics and antioxidant activities were measured during the experiment. The results revealed that salinity reduced both fresh and dry weight of leaves and roots in canola plants. The highest fresh and dry weights of roots and leaves were observed in control, while salinity at 200 mM decreased significantly both root and leaf weight during time. Both peroxidase and IAA oxidase activities were significantly increased in 200 mM treatment during time, however, at 100 mM salinity level the activity of antioxidants was unchanged. Both peroxidase and IAA oxidase activities in cytoplasm were higher than that in cell wall. It seems that the increased salinity induced the activities of peroxidase and IAA oxidase in canola.