Effects of Epichloë endophyte on antioxidant enzymes activities, photosynthesis and growth of three ecotypes of Elymus dahuricus

Abstract

Fungal endophytes of some cultivated grasses can increase plant performance and competitive abilities, especially under stress. Far less is known about the influence of Epichloë infections in wild populations of wild grasses. In this study, plants of three Elymus dahuricus ecotypes (WLS, QY and WTS) either infected with Epichloë endophyte (E+) or uninfected (E-) were grown in the field. The activities of the antioxidant enzymes ascorbate peroxidase, catalase, peroxidase and superoxide dismutase, and concentrations of H2O2 and malondialdehyde were examined in the leaves of E+ and E-plants. We also determined photosynthesis parameters, leaf blade and sheath carbohydrate concentration and plant growth parameters of both E+ and E-plants. E+ plants from the WLS and QYpopulations had significantly higher antioxidant enzyme activities and photosynthetic capability (P<0.05), superior growth characteristics including more abundant carbohydrate concentration than E-plants. In contrast, in plants from the WTS population, the endophyte had no significant effect on reactive oxygen species scavenging capability and growth performance (P>0.05), and even displayed some negative effects on plant photosynthetic capability. Thus, endophyte infection significantly affected E. dahuricus antioxidant enzyme activities (P<0.05), photosynthesis and growth capability, although, the effects varied with plant ecotypes.