The Effect of Mycorrhiza-Like Fungus Piriformospora indica on Some Physiological and Biochemical Responses of Alfalfa (Medicago sativa L.) under Water Deficit Stress

The root endophyte Piriformospora indica is plant growth promoting and induces tolerance to biotic and abiotic stresses in plants. To assess the effect of P. indicainoculation onMedicago sativaL. plantsunder water deficit stress, a trial was conducted in a factorial experiment based on completely randomized design with combination of two factors, soil moisture levels (100% AW (Available Water) and 30% AW) and fungi (inoculated with P. indica and non-inoculated) in three replications. The M. sativa seedlings (inoculated or non-inoculated ) were exposed to water deficit stress for the 45 days. The plant shoot and root biomass were increased by fungal inoculation that indicated growth promoting effect of P. indica. A significant decrease in plant biomass, leaf relative water content and mineral content were observed under water deficit stress. In this study fungal inoculation caused a significant increase in P, Zn, proline and protein contents in shoot and root, root phenol and Fe contents as well as chlorophyll and carotenoid contents at 30% AW in comparison with those in non-inoculated plants. Also, malondialdehyde in inoculated plants was lower than that in non-inoculated plants under both moisture levels. Generally, our results showed that the P. indica inoculation counteracted water deficit stress conditions in M. sativa and it could be proposed as a useful tool for alleviating the adverse effects of water deficit stress in host plant.