Effect of Epichloë gansuensis endophyte and transgenerational effects on the water use efficiency, nutrient and biomass accumulation of Achnatherum inebrians under soil water deficit

Abstract

This study explored the effects of Epichloe gansuensis endophyte on water use efficiency (WUE), nutrient content and biomass accumulation of Achnatherum inebrians (drunken horse grass, DHG) under varying water availability. It also examined possible transgenerational effects (TGE) on above indicators. DHG with (EI) and without endophyte (EF), from seed of plants of the same seed-line that had been grown in Yuzhong (YZ-D, relatively dry) and Xiahe (XH-W, relatively wet), were grown under limited water conditions (LWC). Plant height, leaf number and chlorophyll content were monitored dynamically. After 10 weeks, the biomass, photosynthetic indexes and C, N, P content of plants was determined. The endophyte increased plant height and chlorophyll content, but decreased plant leaf number, and the CO2 concentration, while increasing other photosynthetic indexes. The biomass, N and P content were higher in EI than EF plants of the YZ-D DHG, but not the C content and root weight. However, there were almost no significant affects on these factors between EI and EF plants of the XH-W DHG. The endophyte enhanced WUE and maintained the growth of plants under LWC by improving photosynthetic efficiency and promoting nutrient absorption. However, TGE also affected this process.