Identification and Characterization of Three Epichloë Endophytes Isolated from Wild Barley in China

Epichloë endophytes have been found in cool-season grasses and can produce alkaloids that are toxic to vertebrates and insects. Due to their beneficial effects, Epichloë can provide plants with resistance to some abiotic and biotic stresses. The biological and physiological characteristics of the endophytic strains XJE1, XJE2, and XJE3 isolated from wild barley were measured across a range of pH, salt concentrations, and growth values. The phylogenetic position of the Epichloë isolates was examined using the tefA and actG genes. The optimal pH values for mycelial growth of XJE1, XJE2, and XJE3 were 7-8, 6-7, and 8-9, respectively. The isolates grew significantly better at 0.3 mol/L NaCl than at 0.5 mol/L and 0.1 mol/L NaCl. Based on the conidiophore and conidia morphology, growth characteristics, and phylogenetic relationships, the endophyte isolated from wild barley is likely Epichloë bromicola. These isolates exhibited differences in mating types and alkaloid biosynthesis genes. Screening for salt tolerance and alkaloid biosynthetic genes in endophytic strains will provide new insights into useful traits to breed into new forage germplasms.