Effects of multiple climate change factors on the tall fescue–fungal endophyte symbiosis: infection frequency and tissue chemistry

Abstract

Summary• Climate change (altered CO 2 , warming, and precipitation) may affect plantmicrobial interactions, such as the Lolium arundinaceum-Neotyphodium coenophialum symbiosis, to alter future ecosystem structure and function.• To assess this possibility, tall fescue tillers were collected from an existing climate manipulation experiment in a constructed old-field community in Tennessee (USA). Endophyte infection frequency (EIF) was determined, and infected (E+) and uninfected (E)) tillers were analysed for tissue chemistry.• The EIF of tall fescue was higher under elevated CO 2 (91% infected) than with ambient CO 2 (81%) but was not affected by warming or precipitation treatments. Within E+ tillers, elevated CO 2 decreased alkaloid concentrations of both ergovaline and loline, by c. 30%; whereas warming increased loline concentrations 28% but had no effect on ergovaline. Independent of endophyte infection, elevated CO 2 reduced concentrations of nitrogen, cellulose, hemicellulose, and lignin.• These results suggest that elevated CO 2 , more than changes in temperature or precipitation, may promote this grass-fungal symbiosis, leading to higher EIF in tall fescue in old-field communities. However, as all three climate factors are likely to change in the future, predicting the symbiotic response and resulting ecological consequences may be difficult and dependent on the specific atmospheric and climatic conditions encountered.

Endophyte Infection of Tall Fescue and the Impact of Climatic Factors on Ergovaline Concentrations in Field Crops Cultivated in Southern France

“…This result obtained in the field agrees with data obtained in controlled conditions demonstrating the lack of effect of high temperatures on total ergot contents in tall fescue. 34 Finally, this suggests that, during this assay, the correlation observed between ergovaline content in the whole plant and cumulative degree-d is due to an effect of temperature on plant growth. Cumulative rainfall from the beginning of February to the fully ripe stage plotted against ergovaline concentrations in the whole plant showed major differences between years ( Figure 4B).…”

“…Although it has been suggested that a limited supply of water could increase alkaloid production, 23 this result in the field agrees with data obtained under controlled conditions, demonstrating the lack of effect of water availability on total ergot contents in tall fescue. 34 In conclusion, this study demonstrates for the first time that around 60% of wild tall fescue is infected with Epichloe in southern France and that most of the infected plants are able to produce very high ergovaline levels in seeds. Determination of ergovaline contents in Kentucky 31 tall fescue infected with E. coenophiala at different growth stages revealed that the levels in plant can be high and do not markedly differ from levels measured in other countries where fescue toxicosis has been reported.…”

Impacts of climate change on plant diseases—opinions and trends

“…precipitation: Hawkes et al 2011); & with multiple climate change factors (Paajanen et al 2011); & in relation to endophytes and viruses, two key factors for plant health (Jones 2009;Brosi et al 2010); & in relation to mycorrhiza diversity and productivity (Deslippe et al 2010;Egli 2011); & with long-term datasets (Hannukkala et al 2007;Fitt et al 2011 & and considering various plant disease control methods (Ghini et al 2011a). …”

Fungal Endophytic Communities in Grapevines (Vitis vinifera L.) Respond to Crop Management

“…Changes in the composition of plant-associated microbial communities have often been associated with plant physiology (9), health (14), and environmental perturbances (11). In the present study, we examined fungal endophytic communities in grapevines using both cultivation-based and cultivation-independent approaches.…”