Effect of salicylic acid on growth and essential elements’ content in spring canola plants under lead stress

In this research, the interactive effects of lead (Pb) and salicylic acid (SA) on canola plants were studied. 25-dayold plants were exposed to concentrations of Pb (NO3)2 (0, 250 μM ) and SA (0, 100 μM) for 10 days. This research was done in the form of factorial, in a completely randomized design at four repeats with lead and salicylic acid treatments each one at two levels. Lead toxicity symptoms, such as chlorosis and necrosis were observed on leaves of Pb-treated plants. Treatment with Pb resulted in a significant decrease in fresh and dry weight of roots and shoots (p<0.05). Mineral elements content (Mg, Fe, Ca, P, K) extremely decreased in roots and shoots of Pbstressed canola plants (p<0.05), while, the content of N in these plants significantly increased in roots and decreased in shoots (p<0.05). Pb was more accumulated in roots than in shoots. In Pb-stressed plants, application of SA improved the growth and decreased the toxicity symptoms as compared to Pb-treated plants. SA considerably reduced root-to-shoot translocation of Pb and significantly increased the content of mineral elements in roots and shoots of Pb-stressed plants. The results showed that by sequestration of Pb in roots and amelioration of mineral nutrition, SA markedly reduced the toxic effects of lead on canola plants

Keywords:

Salicylic acid , Lead toxicity , Mineral elements , Canola