The effect of Rhizophagus irregularis on salt stress tolerance of Elaeagnus angustifolia roots

We assessed the effects of arbuscular mycorrhizal fungi (AMF) Rhizophagus irregularis inoculation on salt stress tolerance in roots of the drought-tolerant plant Elaeagnus angustifolia. We studied a plant growth index, spore density and hyphal length density of AMF, the Na+ contents and ultrastructure of root cells, as well as rhizosphere soil enzyme activities of mycorrhizal and non-mycorrhizal E. angustifolia seedlings under different salt stress. Under salt stress, growth of E. angustifolia with mycorrhizal inoculation was higher than that of non-inoculated treatments. The spore density and hyphal length density decreased significantly under salt stress in rhizosphere soil of mycorrhizal E. angustifolia seedlings (p < 0.05). The root cells of E. angustifolia seedlings inoculated with R. irregularis at 300 mmol L−1 salt had more organelles, greater integrity, and lower root Na+ contents than those of non-inoculated seedlings. In addition, the results showed notably higher activities of catalase, phosphatase, urease and saccharase in rhizosphere soil of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Therefore, AMF inoculation could enhance salt stress tolerance in roots of E. angustifolia.