Effects of Epichloë Endophyte and Transgenerational Effects on Physiology of Achnatherum inebrians under Drought Stress

Abstract

The present study explored the effects of an Epichloë endophyte on growth and physiology parameters of drunken horse grass (DHG, Achnatherum inebrians) under four different soil water content. The possible transgenerational effects (TGE) on the above-mentioned indicators were examined. DHG plants with (EI) and without (EF) this Epichloë endophyte, grown from seed of plants from the same seed line, were used. The seeds had originated in the relatively dry site at Yuzhong [YZ(D)], and also used were seed of plants from this original seed-line grown at the relatively wet site Xiahe [XH(W)]. The growth, photosynthesis, phytohormones, and elements were measured. This study showed that the endophyte increased the aboveground biomass and chlorophyll content, with the increasing of photosynthetic parameters. The presence of endophyte also significantly promoted abscisic acid and indolE−3-acetic acid content but decreased the cytokinin content. The nitrogen and phosphorus content of EI plants was significantly higher than that of EF plants, but the endophyte decreased ratios of C:N and C:P at drought condition. In addition, TGE were present, affecting host growth and the above-mentioned parameters, and which indicated that the plants grown from the seeds in YZ(D) site are more competitive than those in the XH(W) site under water deficiency conditions.