Understanding context-dependency in plant-microbe symbiosis: The influence of abiotic and biotic contexts on host fitness and the rate of symbiont transmission

▶ Here we examine interactions between a fungal endophyte and its grass host. ▶ Benefits of the symbiosis were strongest when water was limiting. ▶ Benefits appear to accrue by allowing hosts to escape from drought. ▶ The symbiosis may be costly in the presence of soil microbes. ▶ Neither the biotic nor abiotic context altered the rate of symbiont vertical transmission.