Are Epichloë endophytes specific to Elymus grass hosts?

Abstract

ABSTRACT. Epichloë endophytes are widely distributed mutualists of cool-season grasses and can protect their hosts against biotic and abiotic stresses. Previous studies have shown that Epichloë endophytes are specific to their grass hosts in tall Festuca and Lolium species. However, no systematic analysis exists of host specificity of asexual Epichloë endophytes and Chinese Elymus species. We analyzed the phylogenetic relationships between Chinese Elymus species and their diploid donor Hordeum species, using their corresponding Epichloë endophyte sequences. We found that 1) the maternal donor of the Chinese Elymus species was the Chinese Pseudoroegneria (St genome) or Hordeum (H genome); and 2) Chinese Hordeum species probably contained two species of Epichloë endophytes. One Epichloë endophyte was also present in a North American Elymus species. The other Epichloë endophyte was found in a Chinese Elymus species. Our results indicate that Epichloë endophytes isolated from Elymus species did not show grass-host specificity. 3) Plant hybridization could probably transform endophyte-free plants (E-) to endophyte-infected plants (E+). Based on 17463-17471 (2015) our data, we formulate hypotheses about which Epichloë endophytes were spread via plant hybridization.

The Effect of Seed-Borne Fungi and Epichloë Endophyte on Seed Germination and Biomass of Elymus sibiricus

“…isolated from H. brevisubulatum and E. tangutorum were marked as Eb and Et, and the Epichloë gansuensis was marked as Eg. The H. brevisubulatum and E. tangutorum samples were collected from Linze (E:102°54′, N:37°29′; 1,450 m) and Lanzhou (E103°56′, N36°01′; 1,714 m), Gansu Province, China in 2012 (Song and Nan, 2015 ; Song et al, 2015 ).…”

Advances in Research on Epichloë endophytes in Chinese Native Grasses

“…They suspect that migratory birds or humans might have aided the dispersal of Epichloë endophytes from Eurasia to other continents (Song and Nan, 2015). Furthermore, Song et al (2015c) analyzed Hordeum -endophytes and Elymus -endophytes and found that Chinese Hordeum species likely contain two Epichloë endophyte species. One is also found in North American Elymus species and the other endophyte is found in Chinese Elymus species, indicating that Epichloë endophytes isolated from Chinese Hordeum are not host-specific.…”

“…One is also found in North American Elymus species and the other endophyte is found in Chinese Elymus species, indicating that Epichloë endophytes isolated from Chinese Hordeum are not host-specific. They proposed that Epichloë endophytes spread among different grass hosts by plant hybridization, and this could likely transform the hybrid offspring from EF status to EI status (Song et al, 2015c). This needs to be tested in future studies, but it would add further evidence to the hypothesis that asexual Epichloë endophytes are horizontally transmitted (Tadych et al, 2012; Wiewióra et al, 2015).…”