Effect of Epichloe gansuensis endophyte on the activity of enzymes of nitrogen metabolism, nitrogen use efficiency and photosynthetic ability of Achnatherum inebrians under various NaCl concentrations

Background and aimsThis study explored the effects of Epichloe gansuensis endophyte on photosynthetic ability, the activity of nitrogen metabolism enzymes, nitrogen use efficiency, and biomass accumulation of Achnatherum inebrians growing under five NaCl concentrations.MethodsA. inebrians plants with (E+) and without E. gansuensis (E-) were grown under different NaCl concentrations. Photosynthetic indexes, NO3- and NH4+ content, nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) activity, nitrogen use efficiency and nitrogen content were determined.ResultsThe plant total biomass, NO3- and N content, NR, NiR and GS activity, total N accumulation (TNA), nitrogen utilization efficiency (NUtE) and nitrogen uptake efficiency (NUpE) were higher in leaves and roots of E+ than of E- plants under 300 and 400mM NaCl concentrations, but NH4+ content was lower in leaves and roots of E+ than of E- plants under 100, 200, 300 and 400mM NaCl concentrations. However, there were almost no significant effects on these factors between E+ and E- plants under the 0mM NaCl concentration.ConclusionsThe endophyte improved the growth of plants under high NaCl concentration by improving photosynthetic ability, increasing the activity of nitrogen metabolism enzymes and nitrogen use efficiency.