The effect of exogenous melatonin on physiological parameters of quinoa under salt stress

This research has investigated the effect of exogenous melatonin (۰ and ۰.۵μM) on the growth, biochemical and physiological parameters of quinoa plant (Rosada), under salt stress (۰ and ۱۰۰mM). The results showed that salinity stress in the concentration of ۱۰۰ mM lead to reduction of plant growth parameters such as Shoot length, shoot diameter, root length, Shoot dry weight, Root dry weight, Shoot fresh weight and Root fresh weight. Also, stress caused increase of sodium ion and decrease of potassium ion and the ratio of potassium to sodium decrease in the plant. On the other hand, the amount of total chlorophyll and protein decreased. The amount of carotenoids has not had significant different than the control. The mount of malondialdehyde, hydrogen peroxide and lipoxygenase activity increased under salinity stress. In addition, non-enzymatic antioxidants such as total ascorbate and glutathione and the amount of soluble carbohydrates, proline, phenolic compounds, flavonoids and anthocyanins increased significantly under stress. Antioxidant enzymes such as superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase and phenylalanine ammonialyase increased. Melatonin pretreatment has led to significant increase of total chlorophyll, carotenoids, soluble carbohydrates shoot and root proline, protein, total ascorbate and total glutathione. Also, all antioxidant enzymes in this research increased in the presence of melatonin under salinity stress. Therefore, the concentrations of malondialdehyde and hydrogen peroxide decreased. Exogenous melatonin application seems to be a suitable solution to reduce oxidative stress in quinoa and improve growth parameters.

کلیدواژه ها:

Enzymatic Antioxidants ، Non-Enzymatic Antioxidant ، Oxidative Stress