Plant use of endophytic fungi in defense

Plant use of endophytic fungi in defense occurs when endophytic fungi, which live symbiotically with the majority of plants by entering their cells, are utilized as an indirect defense against herbivores. In exchange for carbohydrate energy resources, the fungus provides benefits to the plant which can include increased water or nutrient uptake and protection from phytophagous insects, birds or mammals.

Source: Wikipedia — Plant use of endophytic fungi in defense (CC BY-SA 4.0)