Conserved plant growth promotion via decomposition by ecologically distinct microbiomes

In this study, we explore the relationship between ecologically distinct soil microbiomes and their role in plant growth promotion through organic matter (OM) decomposition. Using a controlled experimental system, we tested whether living microbiomes from geographically and ecologically distinct environments, including agricultural fields, city waste compost, desert, and pine-oak forest, impact plant biomass when provided with organic matter in the form of dried and ground leaves. Results showed a consistent threefold increase in plant biomass when a living microbiome and organic matter were present, regardless of the microbiome's origin. Analyses of 16S rDNA sequencing data indicated that specific genera, such as Massilia, are associated with decomposition and subsequent plant growth promotion. This suggests a conserved functional capacity for organic matter decomposition across diverse microbiomes, likely due to evolutionary pressures to efficiently break down plant material for nutrient acquisition as well as create more substrate to consume. The study provides a framework for further investigation into microbial consortia that enhance plant growth via decomposition, offering a robust experimental system to identify microbes and microbial processes that would be useful in improving nutrient uptake from inputs such as cover crops.