Extreme environments as sources of fungal endophytes mitigating climate change impacts on crops in Mediterranean‐type ecosystems

Climate change is predicted to increase drought and soil salinity in Mediterranean‐type ecosystems (MTEs), posing a significant threat to global food security. Genetic modification of crops to counteract this threat is expensive and has not met with universal support, and alternatives are hence needed to enhance crop production in MTEs. Here, fungal endophytes from the Atacama Desert, High Andes and Antarctica inoculated onto three crops were found to alleviate the negative effects of drought and salinity on plant performance. The study concludes that extremophile endophytes might be used to enhance crop performance as the climate of MTEs changes over future decades. Climate change will curtail the ability to provide sufficient food for our rapidly expanding population. Improvements to crop production in changing environments, particularly Mediterranean‐type ecosystems (MTEs), which are increasingly subjected to drought and salinisation, are hence urgently needed. Here, we explored the possibility that fungal endophytes from extreme environments can be used to enhance crop yield, survival and tolerance to environmental stresses. Plants of lettuce, tomato and bell pepper were inoculated with up to six species of endophytic fungi isolated from the Atacama Desert, the High Andes and Antarctica. They were then exposed in the field for up to 120 days in each of three summers to current climatic conditions or to a future climate scenario simulating increased drought and soil salinisation. Compared with uninoculated plants, the yield and survival of inoculated crops were increased by up to two‐fold under the future climate scenario. These effects were in part attributable to the improved water balance of inoculated crops exposed to drought and salinisation. The inocula also increased the concentrations of total phenols and proline in leaves and decreased lipid peroxidation when plants were subjected to increased aridity and salinity. A mixed inoculum of six endophytes from the extreme environments conferred the most beneficial effects on crop performance, with a commercially available inoculum having fewer positive effects on crops. We conclude that the inoculation of crops with endophytes from extreme environments may be a viable solution to sustaining crop production in MTEs exposed to rapid climate change.