Fungal Endophyte (Epichloë festucae) Alters the Nutrient Content of Festuca rubra Regardless of Water Availability

Abstract

Festuca rubra plants maintain associations with the vertically transmitted fungal endophyte Epichloë festucae. A high prevalence of infected host plants in semiarid grasslands suggests that this association could be mutualistic. We investigated if the Epichloë-endophyte affects the growth and nutrient content of F. rubra plants subjected to drought. Endophyte-infected (E+) and non-infected (E−) plants of two half-sib lines (PEN and RAB) were subjected to three water availability treatments. Shoot and root biomass, nutrient content, proline, phenolic compounds and fungal alkaloids were measured after the treatments. The effect of the endophyte on shoot and root biomass and dead leaves depended on the plant line. In the PEN line, E+ plants had a greater S:R ratio than E-, but the opposite occurred in RAB. In both plant lines and all water treatments, endophyte-infected plants had greater concentrations of N, P and Zn in shoots and Ca, Mg and Zn in roots than E- plants. On average, E+ plants contained in their shoots more P (62%), Zn (58%) and N (19%) than E- plants. While the proline in shoots increased in response to water stress, the endophyte did not affect this response. A multivariate analysis showed that endophyte status and plant line impose stronger differences in the performance of the plants than the water stress treatments. Furthermore, differences between PEN and RAB lines seemed to be greater in E- than in E+ plants, suggesting that E+ plants of both lines are more similar than those of their non-infected version. This is probably due to the endophyte producing a similar effect in both plant lines, such as the increase in N, P and Zn in shoots. The remarkable effect of the endophyte in the nutrient balance of the plants could help to explain the high prevalence of infected plants in natural grasslands.

Ecological patterns of seed microbiome diversity, transmission, and assembly

“…Fungal vertical inheritance is recognized as common mechanism of transfer across generations [39] and vertically transmitted fungal symbionts have been implicated in providing direct benefit to their host plant, such as in the case of improved drought tolerance of Festuca rubra given its fungal endophytre Epichloe¨festucae [40]. Furthermore, some studies have reported vertical transmission rates of greater than 90% for many fungal endosymbionts [41 ].…”

cAMP Signaling Regulates Synchronised Growth of Symbiotic Epichloë Fungi with the Host Grass Lolium perenne

“…Several classes of endophyte metabolites with mammalian and insect toxicity, as well as invertebrate deterrent effects, have been characterized (Schardl and Phillips, 1997; Schardl et al, 2007, 2013). Epichloë infection can also elevate the tolerance of grasses to certain abiotic stresses (Arachevaleta et al, 1989; Malinowski and Belesky, 2000; Vázquez-de-Aldana et al, 2013). Given these attributes, these fungi are often prevalent in native grass habitats, but are also essential for persistence of forage in managed pastoral farming systems where insect pressure is high, as in New Zealand, Australia, and the Americas (Johnson et al, 2013a).…”

Biomass yield, nutritive value and accumulation of minerals in Trifolium subterraneum L. as affected by fungal endophytes

“…These effects could be a consequence of the substantial benefits that endophytic fungi may confer on hosting plants, such as drought tolerance (Hall et al 2014), resistance to herbivory and pathogens (Thom et al 2013;Romeralo et al 2015), enhanced nutrient uptake (Yang et al 2014), and increased competitive ability (Vázquez-de-Aldana et al 2013). However, this influence appears to be variable and clearly dependent on the species of endophyte, the host genotype and environmental conditions (Ahlholm et al 2002).…”