Endophyte-mediated salinity tolerance is largely unknown in tall fescue [Schedonorus arundinaceus (Schreb.)]. The experiment was designed to characterize growth, ion accumulation, and antioxidant metabolism of tall fescue infected by the endophyte Epichloë coenophiala to different levels of salinity stress. Endophyte-infected (E +) and endophyte-free (E−) tall fescue (cv Kentucky 31) plants were exposed to 10 d of 0 (unstressed control), 100 and 200 mM NaCl treatments in a greenhouse, respectively. Salinity stress caused reductions in plant height, leaf fresh weight (LFW), leaf dry weight (LDW), and leaf water content (LWC), and increased Na⁺ concentration, but E + plants had significantly higher LFW, LDW, and LWC under both NaCl treatments and lower Na⁺ than E− plants under 200 mM NaCl. Salinity stress decreased K⁺ and Mg²⁺ and did not alter P, and increased Ca²⁺ in E + plants and caused no change in Ca²⁺ in E− plants; however, endophyte had no effects on these elements. Chlorophyll fluorescence (Fv/Fm), malondialdehyde (MDA) concentration, and activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) remained unchanged in E + plants, but Fv/Fm was reduced and MDA level and enzyme activities were elevated in E− plants under 200 mM NaCl, where E + plants had significantly higher Fv/Fm and lower MDA, SOD, and APX activities than E− plants. Peroxidase activities increased in E + plants under 200 mM NaCl and in E− plants under both NaCl treatments. The results indicated that endophyte promoted salinity tolerance in tall fescue through maintaining higher growth and photochemical efficiency and lowering Na⁺ accumulation and lipid peroxidation. The significantly induced antioxidant enzyme activities and lipid peroxidation in E− plants suggested a possible enhanced oxidative injury in endophyte-free plants exposed to a high level of salinity stress.

在高羊茅 [ Schedonorus arundinaceus  (Schreb.)] 中，内生菌介导的耐盐性在很大程度上是未知的。该实验旨在表征被内生菌Epichloë coenophiala感染的高羊茅在不同盐度胁迫下的生长、离子积累和抗氧化代谢。内生菌感染的 (E +) 和无内生菌 (E-) 的高羊茅（cv Kentucky 31）植物分别在温室中暴露于 10 天的 0（无应激对照）、100 和 200 mM NaCl 处理。盐分胁迫导致株高、叶片鲜重（LFW）、叶片干重（LDW）和叶片含水量（LWC）降低，Na ⁺浓度增加，但 E + 植株的 LFW、LDW 和 LWC 在NaCl 处理和降低 Na⁺比 200 mM NaCl 下的 E- 植物。盐度胁迫降低ķ ⁺和Mg ²⁺和不改变P，和增加的Ca ²⁺在E +的植物和引起的Ca无变化²⁺在 E- 植物中；然而，内生菌对这些元素没有影响。E + 植物中的叶绿素荧光 (Fv/Fm)、丙二醛 (MDA) 浓度以及超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 和抗坏血酸过氧化物酶 (APX) 的活性保持不变，但 Fv/Fm 降低，MDA 水平在 200 mM NaCl 下，E- 植物的酶活性升高，其中 E+ 植物的 Fv/Fm 显着高于 E-植物，而 MDA、SOD 和 APX 活性更低。在 200 mM NaCl 下的 E + 植物和在两种 NaCl 处理下的 E- 植物中过氧化物酶活性增加。结果表明，内生菌通过保持较高的生长和光化学效率以及降低 Na ^{+ 来}促进高羊茅的耐盐性。积累和脂质过氧化。E-植物中显着诱导的抗氧化酶活性和脂质过氧化表明，暴露于高水平盐度胁迫的无内生菌植物的氧化损伤可能增强。