Static magnetic field-induced changes in the growth, photosynthetic pigments, antioxidative enzyme activities, and secondary metabolites of Echium amoenum seedlings

The magnetic field is an unavoidable physical factor in nature that can affect the growth and development of living organisms. In this study, magnetic field impact was studied on the growth and secondary metabolite of Echium amoenum seedlings through photosynthetic pigments, hydrogen peroxide content, and enzymatic and non-enzymatic defense systems. The disinfected seeds of E. amoenum were cultivated in Morashige and Skoog medium and then exposed to different intensities of static magnetic field (0, 4, and 8 Militesla (mT)) at 1.5 and 3 hours. After three weeks, seedlings were harvested for growth and biochemical analyses. Magnetic field at 4 mT increased dry weight, root and stem length, number of adventitious roots, chlorophyll a and b pigments, and relative water content. Hydrogen peroxide content enhanced with the rise in the intensity and duration of magnetic field, and its highest level was identified at 8 mT for 3 hours with a 2.2-fold rise compared to the control. Antioxidant enzyme activities, including superoxide dismutase, catalase, ascorbate peroxidase, and antioxidant metabolites increased under magnetic field, and the highest activity of antioxidant enzymes was observed at 4 mT for 3 hours. Increasing intensity and duration of magnetic field application (8 mT for 3 hours) showed the toxicity impact on the enzyme activities and defensive metabolites. It seems that the defensive responses to the magnetic field are related to hydrogen peroxide level and the treatment of 4 mT is the appropriate intensity to stimulate the growth and production of antioxidant metabolites in the E. amoenum seedlings.