Effect of Glomus mosseae and Piriformospora indica on Growth and Antioxidant Defense Responses of Wheat Plants Under Drought Stress

Abstract

This experiment aimed to investigate the effects of arbuscular mycorrhizal (Glomus mosseae) and endophytic (Piriformospora indica) fungi on lipid peroxidation, antioxidant enzymes activity, and growth of wheat (Triticum aestivum cv. Azar2) under drought stress conditions. The plants were cultivated in a sterile mixture of soil and sand in a greenhouse. Four levels of fungi inoculations (control, G. mosseae, P. indica, and co-inoculation with both fungi) and three levels of soil moisture conditions (field capacity or FC, -5 and -10 bar) were the treatments. The results showed that with increasing in drought severity, the content of hydrogen peroxide and the activities of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), and peroxidase (POX, EC 1.11.1.7) enzymes increased, while leaf chlorophyll content, plant vegetative growth, and fungi colonization decreased. However, there was no change in lipid peroxidation. The inoculated plants with G. mosseae and P. indica (either alone or mixed) had significantly lower levels of both hydrogen peroxide and lipid peroxidation rate, whereas increased antioxidant enzymes such as CAT, APX and POD, and leaf chlorophyll content. The inoculated wheat plants in various moisture levels had better vegetative growth than the non- inoculated plants. Co-inoculated plants, however, had more root colonization than G. mosseae and P. indica inoculated at all moisture levels. The results of the present study indicate that the plant-fungi symbiosis especially co-inoculation of G. mosseae and P. indica markedly improved the defense mechanisms, drought resistance, and growth of wheat plants.