Role of Jasmonic and Salicylic Acid on Enzymatic Changes in the Root of Two Alyssum inflatum Nayr. Populations Exposed to Nickel Toxicity

Phytohormones, including salicylic acid (SA) and jasmonic acid (JA) have the potential to ameliorate plant development and tolerance to deleterious effects of toxic metals like nickel (Ni). Therefore, the current study was carried out to evaluate SA and JA's interactive effect on the root antioxidative response of two Alyssum inflatum Nyar. populations against Ni-toxicity. Two A. inflatum species under different Ni concentrations (0, 100, 200, and 400 mu M) were exposed to alone or combined levels of SA (0, 50, and 200 mu M) and JA (0, 5, and 10 mu M) treatments. Results showed that high Ni concentration (400 mu M) reduced roots fresh weight in both populations than in control. However, external application of individual SA and JA or combined SA + JA in higher doses had ameliorated roots biomass by mitigating Ni-toxicity, especially in the NM population, in comparison to 400 mu M Ni. Under Ni toxicity, SA and JA, especially their combination, induced high Ni accumulation in plants' roots. Moreover, the application of SA and JA alone, as well as combined SA + JA, was found to be effective in the scavenging of hydrogen peroxide by improving the activity of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in both populations under Ni-toxicity. Overall, our results manifest that SA and JA's external use, especially combined SA + JA treatments, ameliorate root biomass and plant tolerance by restricting Ni translocation to the shoot, accumulating in roots, and enhancing antioxidant defense systems.

Automated summary

The study shows that the external application of salicylic acid (SA) and jasmonic acid (JA) can improve the root antioxidative response of two populations of Alyssum inflatum Nyar. against nickel (Ni) toxicity. The combination of SA and JA is especially effective in restricting Ni translocation to the shoot, accumulating in roots, and enhancing antioxidant defense systems, thereby improving root biomass and plant tolerance.