Context. Infecting grasses with an Epichloë endophyte contribute significantly to host plant salt tolerance. The Epichloë endophyte alkaloid peramine is primarily responsible for feeding deterrence against some herbivorous insects. Infection by an Epichloë is required for peramine production in the host grass. Limited information is available regarding the effects of salinity stress on Epichloë endophyte colonisation and associated production of peramine metabolites.
Aims and methods. In this study, we determined the effects of NaCl stress on the concentration of endophytic hyphae and peramine in wild barley (Hordeum brevisubulatum (Trin.) Link) seedlings infected with Epichloë bromicola.
Key results. Seedings dry weight at 4 weeks declined from 7.05 to 4.27 g/plant over the range, 0-300 mM NaCl. The hyphal concentration, as well as the peramine concentration, increased in response to high NaCl concentrations, hyphae and peramine concentration at 4 weeks increased from 13.29 to 264.60 copies/ng gDNA and from 26.75 to 43.19 μg/g DW, respectively. Peramine concentration was positively correlated with the concentration of hyphae (R2 = 0.4012, P < 0.001).
Conclusions and implications. It seems that peramine concentration was mostly explained by the in-planta variation in endophyte hyphae concentration in wild barley infected with Epichloë species under highly saline conditions.
