Can the defensive mutualism between grasses and fungal endophytes protect non-symbiotic neighbours from soil pathogens?

PÉREZ, L.I. ; GUNDEL, P.E. ; OMACINI, M.

PLANT AND SOIL

SPRINGER

Lugar: Berlin; Año: 2016 vol. 405 p. 289 - 298

0032-079X

Background andaims Itis proposed that Epichloë endophytes have arole protecting host grasses against pathogens. However, it is unclear whetherthis protection is extended to other non-symbiotic plants. Here we explored theeffect of the asexual fungal symbiont, Epichloëoccultans,on the interaction between Lolium multiflorum hostplants and soil pathogens, and its potential positive side-effect onneighbouring plants. Methods We conducted twomicrocosm experiments to assess the endophyte effect on seedling establishmentof the host grass and other non-symbiotic grasses in the presence of soilpathogens.With an in-vitro experiment, we tested whether the endophyteinhibits, during seed germination, the growth of these pathogens. Results Independently of pathogen identity, theendophyte improved host establishment (6 %). The endophyte also enhanced theestablishment of the neighbouring grass Bromuscatharticus (≈20 %) only in soilwith Rhizoctonia solani. The endophyte in seed reduced thegrowth (≈20 %) of two out offour pathogens (Fusarium acuminatum andR. solani). Conclusions Weconclude that asexual endophytes could protect host grasses against pathogensbut most importantly, that they can have protective effects beyond their hosts.Since effects depended on pathogen and plant identity, more experiments areneeded in order understand the ecological meaning of these positive side-effects.