Interactive Effects of Epichloe Endophytes and Arbuscular Mycorrhizal Fungi on Saline-Alkali Stress Tolerance in Tall Fescue

Epichloe endophytes and arbuscular mycorrhizal fungi (AMFs) are two important symbiotic microorganisms of tall fescue (Lolium arundinaceum). Our research explores the combined effects of endophytes and AMF on saline-alkali stress. The finding revealed that a significant interaction between Epichloe endophytes and AMF, and saline-alkali stress occurred in the growth and physiological parameters of tall fescue. Endophyte infection significantly enhanced tall fescue resistance to saline-alkali stress by increasing shoot and root biomass and nutrient uptake (organic carbon, total nitrogen, and total phosphorus concentration), and accumulating K+ while decreasing Na+ concentration. Furthermore, the beneficial effect of endophytes was enhanced by the beneficial AMF, Claroideoglomus etunicatum (CE) but was reduced by the detrimental AMF, Funneliformis mosseae (FM). Our findings highlight the importance of interactions among multiple microorganisms for plant performance under saline-alkali stress.