Data from: Ungulate saliva inhibits a grass-endophyte mutualism

Fungal endophytes modify plant–herbivore interactions by producing toxic
alkaloids that deter herbivory. However, studies have neglected the direct
effects herbivores may have on endophytes. Antifungal properties and
signalling effectors in herbivore saliva suggest that evolutionary
pressures may select for animals that mitigate the effects of
endophyte-produced alkaloids. Here, we tested whether saliva of moose
(Alces alces) and European reindeer (Rangifer tarandus) reduced hyphal
elongation and production of ergot alkaloids by the foliar endophyte
Epichloë festucae associated with the globally distributed red fescue
Festuca rubra. Both moose and reindeer saliva reduced the growth of
isolated endophyte hyphae when compared with a treatment of distilled
water. Induction of the highly toxic alkaloid ergovaline was also
inhibited in plants from the core of F. rubra's distribution when
treated with moose saliva following simulated grazing. In genotypes from
the southern limit of the species' distribution, ergovaline was
constitutively expressed, as predicted where growth is environmentally
limited. Our results now present the first evidence, to our knowledge,
that ungulate saliva can combat plant defences produced by a
grass–endophyte mutualism.