Synthetic Microbial Communities—A New Frontier in Plant Microbiology

Plants have coevolved with microbes for nearly 500 million years; however, their interrelationship is not well understood. Plant roots have an intricate relationship with soil microbes. Such relationships mold the growth, development, immunity and physiology of plants and thus are of immense interest to agriculture and the environment. Technological advancements in sequencing, imaging, omics, synthetic biology and artificial intelligence have allowed scientists to dissect such relationships to a higher resolution. Thus, these advances have facilitated a deeper understanding of plant–microbe interactions and their role in the life cycle of plants and the environment. However, factors such as microbial diversity, microbial abundance, heterogeneity of soil and plasticity of the environment have precluded a clear in situ understanding of microbial community structure. Thus, constructing synthetic microbial communities or SynComs and investigating their effect on plants in a controlled environment offers a reductionist and manageable approach to understand plant–microbe relationships. This approach reduces the confounding variables present in the natural environment and facilitates the understanding of such complex interactions. Members of such communities are identified using 16S rRNA sequencing and are constructed using few microorganisms; often fungal strains are added for cross-kingdom SynComs. Metabolic modeling, metabolic cross-feeding along with ecological and evolutionary principles, can be used while choosing candidates for SynComs. Scalability, transferability, reproducibility, predictability and stability are the major bottlenecks in SynCom research. This emerging area of science may have transformative impact in agriculture, environment and space colonization. In this article, we present our perspective on the latest advancements, challenges and future potential of this technology.