A Friend in Need (of Nutrients) Is a….

Endophytic fungi are found within the roots of healthy plants, but their function is poorly understood. In this issue, Hiruma et al. demonstrate that, under phosphate-limiting conditions, the endophytic fungus, Colletotrichum tofieldiae, provides growth-promoting and fitness benefits to Arabidopsis, but the plant must restrict fungal growth or risk pathogenesis.