New research from Northern Arizona University points to the idea that under some conditions plants can "curate" their microbiomes—selecting good microbes and suppressing harmful ones—to adapt to their environments. The findings have significant implications for sustainable agriculture and offer a greater understanding of how complex ecosystems adapt in a changing environment.
Regents' Professor Nancy Collins Johnson in the School of Earth and Sustainability at NAU and professor César Marín from Universidad Santo Tomás in Chile authored the paper, published in July in The ISME Journal , introducing the concept of functional team selection.
Put simply, plants have a microbiome in and around their roots that is composed of diverse communities of fungi, bacteria, viruses and other microorganisms. These communities help plants get nutrients and water from soil and protect plants from stress and disease. For decades, people have attempted to recreate these diverse communities, and their beneficial effects, commercially. However, these products often fail to provide the expected benefits to plants.
Functional team selection (FTS) can explain why. FTS offers a holistic perspective that envisions plants and their associated microbiomes as diverse systems of interacting organisms and viruses. Functional microbiome teams may evolve that help plants grow and thrive in seemingly difficult environments. When resources are low, if there's enough time and a mix of helpful microbes, then plants and fungi that naturally live together can form mutually beneficial partnerships, which helps the plants grow.
"Functional teams are unlikely to evolve in benign environments with no stress and ample resources because they lack the selection pressure that is required to curate the composition of the microbiome," Johnson said. "Evidence for FTS can be seen in studies showing that fertilization of natural vegetation often reduces mycorrhizal benefits by removing the essential selection pressure."
Functional Team Selection is based on both ecological and evolutionary theories, including the newly proposed Law of Increasing Functional Information that explains the roles of function and selection in the evolution of all types of systems in the universe. Although FTS was developed to understand the evolution and functioning of plants and their belowground microbiomes, the FTS framework could help us understand and better manage all kinds of microbiomes that provide important functions for humans.
