The defensive role of foliar endophytic fungi for a South American tree

Fungal endophytes colonize living internal plant tissues without causing any visible symptoms of disease. Endophytic fungi associated with healthy leaves of the South American tree Embothrium coccineum (Proteaceae) appear to play an important role in host protection in nature. A recent study published in AoB PLANTS by González-Teuber showed that a few common taxa dominated the fungal endophyte community in leaves of E. coccineum, and that higher infection rates of the dominant endophyte genera correlated with lower levels of leaf damage in the host plant. Furthermore, in vitro confrontation assays indicated that foliar endophytic fungi were able to successfully reduce the growth of fungal pathogens. These results provide evidence that colonization by multiple foliar endophytic fungi confers important benefits to host plants in terms of resistance to natural enemies in the field.