نقش دوگانه متیل جاسمونات بر عملکردهای فیزیولوژیک در گیاه سویا (Glycine max L.)

Abstract: Jasmonic acid and its methyl ester, methyl jasmonate (MeJA), are naturally occurring plant growth regulators, which can affect many physiological and biochemical processes in plants. In present investigation, the effects of methyl jasmonate (0, 1, 10, 100 and 500µM) on some physiological and antioxidative responses in soybean (Glycine max L.) plants were studied. Under MeJA (1 and 10 µM) treatments, shoot dry weight and chlorophyll content increased and lipid peroxidation decreased. Treatment of plants with methyl jasmonate, especially at 100 and 500 µM concentrations reduced shoot dry weight and total chlorophyll content and increased lipid peroxidation. All concentrations of MeJA increased the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POD) and also increased the content of ascorbate pool, phenolic compound and anthocyanins as well. Based on our results, it seemed that the application of methyl assonate at low concentrations enhanced the antioxidant defence system, at the same time, decreased lipid peroxidation and improved growth parameter. The higher concentrations of methyl jasmonate increased lipid peroxidation and reduced plants growth, so that increasing the antioxidant capacity of plants did not decrease the oxidative stress and did not improve plants growth.