DOI: 10.5061/dryad.06hn6
title: Data from: Ungulate saliva inhibits a grass-endophyte mutualism

description: 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.
description: Ergovaline
 concentrations in simulated herbivory experimentData are from an
 experiment simulating herbivory and saliva application on 32 Festuca rubra
 plants infected with Epichloë festucae. We used two simulated herbivory
 treatments consisting of fortnightly and monthly clipping and a control of
 no herbivory. Clipped plants received either distilled water or moose
 saliva. The 32 plants represented 22 isolates (putatively different
 genets), originating from either the core of F. rubra’s distribution in
 Europe, mainly Sweden, or its natural southern limit in southern Ontario,
 Canada. Plants were harvested after growing in a greenhouse for eight
 weeks and measured for ergovaline concentrations using high-performance
 liquid chromatography at the Endophyte Service Laboratory, Oregon State
 University.ErgoExpt_TanentzapDryad.csvRadii of Epichloë festucae colonies treated with saliva or water measured every 12 hoursWe tested whether application of reindeer and moose saliva reduced in vitro growth of Epichloë festucae colonies relative to a control treatment of distilled water. We isolated E. festucae from Festuca rubra, grown from natural populations in northern Sweden, by cutting the base of the youngest fully-extended leaf in each plant. Sections were surface sterilized and embedded in potato dextrose medium with 60 mg/L of penicillin G and streptomycin. Plates were stored in the dark at 24°C for 2 weeks. We then assigned 22-25 colonies per treatment, with 5-9 replicates of three plant genotypes, and recorded the initial radius of each plate. Saliva was applied and we measured colony radius relative to the baseline every 12 hours over 2 days.ColonyExpt1_TanentzapDryad.csvRadii of Epichloë festucae colonies treated with saliva or water measured every 8 hoursWe tested whether application of reindeer and moose saliva reduced in vitro growth of Epichloë festucae colonies relative to a control treatment of distilled water. We isolated E. festucae from Festuca rubra, grown from natural populations in northern Sweden, by cutting the base of the youngest fully-extended leaf in each plant. Sections were surface sterilized and embedded in potato dextrose medium with 60 mg/L of penicillin G and streptomycin. Plates were stored in the dark at 24°C for 2 weeks. We then assigned 22-25 colonies per treatment, with 5-9 replicates of three plant genotypes, and recorded the initial radius of each plate. Saliva was applied and we measured colony radius relative to the baseline every 8 hours over 2 days.ColonyExpt2_Dryad.csv