Modulating Mycorrhiza-Plant Relationships and Improving the Physiological Responses of Barley Under Drought Stress Conditions with the Application of Methyl Jasmonate

Jasmonates are believed to affect plant growth under stress conditions by improving the plant's antioxidant defense. They can also interfere in the mycorrhizal symbiosis. There is no detailed information available on the effect of methyl jasmonate (MeJ) on the physiology of barley; investigating the effect of this phytohormone on the relationships between fungus and plant, the combined effect of application of these two factors on the growth and physiology of the plant is a new perspective in sustainable agriculture. The present factorial experiment was conducted with three factors as a pot experiment. The plants were grown with inoculation with Funneliformis mosseae (AM) and application of 75 mu M MeJ under drought stress conditions. Each of the treatments alone (+ MeJ - AM and - MeJ + AM) improved the plant growth under drought by fortifying the antioxidants defense. Although + MeJ - AM was found to be the most effective treatment under stress conditions, it caused some damages by reducing chlorophylls under non-stress conditions. Meanwhile, the highest plant growth under non-stress conditions belonged to - MeJ + AM. Application of MeJ along with AM reduced the damage caused by MeJ under non-stress conditions by taking advantage of the potential of mycorrhiza and improving symbiosis. However, under stress conditions, this treatment resulted in better plant growth compared to - MeJ + AM and - MeJ - AM with the positive effects of MeJ on the antioxidant system. Generally, due to the inevitable imposition of drought stress in the period of plant growth under normal conditions, it seems as if the combination of these treatments could be considered in future.