Growth and anti-oxidative systems changes in Elymus dahuricus is affected by Neotyphodium endophyte under contrasting water availability

Although the relationship between fungal endophyte and agronomic grass (Lolium perenne and Festuca arundinacea) in drought tolerance are well documented, the mechanisms responsible for wild grass are not well understood. In this study, we determined the biomass production and growth parameters endophyte infected (E+) and endophyte uninfected (E-) Elymus dahuricus plants under high water (HW) and low water (LW) treatment for 8 weeks in a controlled-environment condition experiment. We also determined the changes in the activities of the anti-oxidative enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX) and content of H2O2, as well as levels of proline and chlorophyll a + b were examined in the leaves of E+ and E- plants. Under low water treatment, E+ plants produced more biomass and had higher values in plant height and tiller numbers, but no influence by the fungus were observed in high water treatment. Anti-oxidative enzyme (include SOD, POD, CAT and APX) activities and contents of proline and chlorophyll a + b increased and H2O2 concentration declined in the E+ plants compared with E- plants under low water treatment. Therefore, endophyte infection was a benefit to growth and anti-oxidative affection E. dahuricus under low water treatment.