Ecological functions, inter-organismal interactions, and underlying mechanisms of fungal endophytes

Background

Plants harbor fungi within their internal tissues in mutualistic associations, interacting at the molecular level to bring about favorable changes for the host plant to reap ecological benefits, including increased growth, fitness, and stress tolerance. These fungi, known as endophytes, are universally present in all plants, with each host species harboring a specific fungal microbiome.

Scope

We are now beginning to understand the dynamics of such interactions and the molecular mechanisms that drive their ecological functions. In the present climate change scenario, to ensure food security, we need to study plants as holobionts to apply this knowledge in sustainable crop production and the cultivation of economically and medicinally important plants. In this review article, we present the current status of the role of fungal endophytes in plant growth enhancement and mitigation of environmental stresses. We thoroughly discuss the mechanisms of endophyte colonization, factors affecting their diversity and symbiosis, and the mechanisms underlying endophyte-based plant protection and host development. Further, we highlight the role of endophytes in inducing host resistance against biotic and abiotic stress factors and the functions of volatile organic compounds (VOCs) in the inter-organismal molecular talk between the symbiotic partners.

Conclusion

Understanding these mechanisms will facilitate the application of endophytes as green alternatives for replacing harmful pesticides and chemical fertilizers.