Methyl jasmonate (MeJA) is a naturally occurring plant growth regulator and play vital roles in plant defense and many developmental processes such as root growth and seed germination. This study was undertaken to study the possible role of using methyl jasmonate to alleviate the adverse effect of water stress on soybean genotypes (Giza 22 and 35). The results showed that water stress reduced shoot length, fresh and dry weights of shoot and root, photosynthetic pigments, relative water content and oil content in the shoots of all soybean genotypes. On the other hand, there was a considerable increase in cell wall fractionation, saturated and unsaturated fatty acids, flavonoids, phenolic acid and sugar fraction content in the shoots of the soybean genotypes in response to the water stress. Foliar spray with methyl jasmonate increased all the above parameters as compared to stressed plants. The results investigate the important role of MeJA in alleviation of water stress in soybean plants and suggest that MeJA could be used for improving plant growth under water stress as a potential growth regulator. The soybean genotypes Giza 22 was found to be more resistant to water stress than Giza 35.
Keywords: Fatty acid; Flavonoids; Phenolic; Photosynthetic pigments; Relative water content; Sugars fractions.