Role of Epichloe Endophytes in Improving Host Grass Resistance Ability and Soil Properties

The past decade has witnessed significant advances in understanding the interaction between grasses and systemic fungal endophytes of the genus Epichloe, with evidence that plants have evolved multiple strategies to cope with abiotic stresses by reprogramming physiological responses. Soil nutrients directly affect plant growth, while soil microbes are also closely connected to plant growth and health. Epichloe endophytes could affect soil fertility by modifying soil nutrient contents and soil microbial diversity. Therefore, we analyze recent advances in our understanding of the role of Epichloe endophytes under the various abiotic stresses and the role of grass-Epichloe symbiosis on soil fertility. Various cool-season grasses are infected by Epichloe species, which contribute to health, growth, persistence, and seed survival of host grasses by regulating key systems, including photosynthesis, osmotic regulation, and antioxidants and activity of key enzymes of host physiology processes under abiotic stresses. The Epichloe endophyte offers significant prospects to magnify the crop yield, plant resistance, and food safety in ecological systems by modulating soil physiochemical properties and soil microbes. The enhancing resistance of host grasses to abiotic stresses by an Epichloe endophyte is a complex manifestation of different physiological and biochemical events through regulating soil properties and soil microbes by the fungal endophyte. The Epichloe-mediated mechanisms underlying regulation of abiotic stress responses are involved in osmotic adjustment, antioxidant machinery, photosynthetic system, and activity of key enzymes critical in developing plant adaptation strategies to abiotic stress. Therefore, the Epichloe endophytes are an attractive choice in increasing resistance of plants to abiotic stresses and are also a good candidate for improving soil fertility and regulating microbial diversity to improve plant growth.