THE COOPERATION BETWEEN METHYL JASMONATE AND SALICYLIC ACID TO PROTECT SOYBEAN (GLYCINE MAX L.) FROM SALINITY

Methyl jasmonate (MeJA), a methyl ester of jasmonic acid, is a naturally produced phytohormone that regulates plant growth and development by maintaining the morphologic, physiological, and biochemical development of plants. The purpose of this study was to determine the effect of methyl jasmonate and endogenous salicylic acid on the stimulation and scavenging of reactive oxygen species (ROS) under salt stress in soybean roots and leaves. Soybean leaves were sprayed with 0.5 mu M methyl jasmonate for 4 days, followed by exposure to 200 mM NaCl. Foliar application of MeJA did not change the leaf area; however, it increased the relative water content (RWC), chlorophyll content, relative electrolyte leakage (REL), and root and shoot fresh weight, and it lessened the stress-induced oxidative damage by decreasing the levels of hydrogen peroxide (H2O2), malondialdehyde (MDA). Curiously, catalase (CAT) enzyme and isoenzyme activity, and also endogenous salicylic acid (SA) were decreased by MeJA treatment. As a result, this study firstly determined that MeJA treatment improved the soybean performance under salinity by acting role as an antioxidant and cooperating with SA.