An Epichloë endophyte affects the competitive ability of Festuca rubra against other grassland species

Abstract

Background and aims: Festuca rubra plants are asymptomatically infected by the systemic fungal endophyte Epichloë festucae and high infection rates have been found in natural grasslands. Our objective was to determine the effect of endophyte infection on the competitive ability of Festuca rubra in binary mixtures against other grassland species. Methods: In two glasshouse experiments, endophyte-infected (E+) and non-infected (E-) plants of two half-sib lines (PEN, RAB) of Festuca rubra were grown in monocultures and in binary mixtures against five grassland species: Trifolium repens, Trifolium pratense, Trifolium subterraneum, Lotus corniculatus and Plantago lanceolata. Results: Biomass production of F.rubra was affected by endophyte infection and plant line but not by competition with T.pratense. In the PEN line E+ plants produced less root biomass than E-; and in the RAB line E+ plants produced less shoot biomass than E-. In spite of these differences shoot and root biomass production of Trifolium pratense were more inhibited when growing with endophyte-infected plants of Festuca rubra than with E-plants, regardless of the plant line. In both F.rubra lines, the endophyte increased the phosphorus concentration in shoots. Regardless of F.rubra plant line, root biomass of the five target species was more inhibited when growing with endophyte-infected than with endophyte-free plants. Conclusions: Irrespective of F.rubra line, endophyte-infected plants had a better competitive ability than non-infected plants, as indicated by the lower relative yield of companion plants when growing in mixture with E+ plants. We suggest an allelopathic effect of E+ red fescue on other grassland species.

Fungal endophyte symbiosis alters nitrogen source of tall fescue host, but not nitrogen fixation in co-occurring red clover

“…In contrast, three genotypic strains of Epichloë lolii (previously Neotyphodium lolii Leuchtmann et al 2014), another asexual fungal endophyte species, infecting perennial ryegrass decreased growth of white clover when grown in mixture, but differences between endophyte strains were not attributed to strain-specific alkaloid profiles (Sutherland et al 1999). Root and leaf extracts of red fescue infected with Epichloë festucae reduced seed germination of both red and white clover (Vázquez-de-Aldana et al 2011), and E. festucae-infected red fescue has also been shown to inhibit red clover biomass production and reduce growth of other legumes when grown in mixture (Vázquez-de-Aldana et al 2013). Furthermore, in tall fescue, Peters and Mohammed Zam (1981) found reduced germination and root growth of red clover and birdsfoot trefoil when subjected to tall fescue extracts of unknown endophyte status, and Springer (1996) later found that extracts from both E-and CTE+ tall fescue reduced red clover germination and root growth.…”

Plant endophytes and arbuscular mycorrhizal fungi alter plant competition

“…() and Vázquez‐de‐Aldana et al. () who found positive effects of endophyte infection on the interspecific competitive ability of host plants. Our results further suggest that endophytes facilitate coexistence between a subordinate plant species ( A .…”

“…grandis , which lacks endophytes. So far, few studies have tested the effects of endophyte infection on the competitive ability of native grasses (Brem & Leuchtmann, ; Craig et al., ; Faeth et al., ; Vázquez‐de‐Aldana et al., ). Our results show that endophyte infection can increase the competitive ability of the host plant A. sibiricum , with higher biomass and aggressivity index than the endophyte‐free plants.…”

Fungal endophytes of Festuca rubra increase in frequency following long-term exclusion of rabbits

“…Epichloë festucae can have highly variable effects on F. rubra growth and biomass production, ranging from no effect (Zabalgogeazcoa et al 2006) to negative (Vázquez-de-Aldana et al 2012) or positive (Wäli et al 2009) effects. Variation in these effects has been linked to plant genotype and habitat of origin (e.g., Vázquez-de-Aldana et al 2012;Wäli et al 2009). Similar to a previous study (Wäli et al 2009), we found that endophyte-infected plants invested more in root over shoot tissues than uninfected plants (Supplementary text, Supplementary Fig.…”

“…Specifically, they can alter host resource allocation to increase their own transmission, which sometimes reduces allocation to plant reproduction (Faeth 2009;Gorischek et al 2013;but see Faeth 2010;Rudgers et al 2010). Conversely, the positive effects of endophytes range from increased competitive ability (Vázquez-de-Aldana et al 2012) and allelopathy (Vázquez-de-Aldana et al 2011) to decreased preference and performance of herbivores on infected grasses (Crawford et al 2010). However, these effects on herbivores can depend on herbivore identity (Afkhami and Rudgers 2009) and endophyte reproductive strategy (i.e., sexual or asexual) (Tintjer and Rudgers 2006).…”