(536d) Insights into Bacterial Secondary Metabolism in Plant-Associated Ecosystems

Discovery of secondary metabolites with an impact on plant-growth are of great importance to sustainable agriculture, as both the chemicals and their hosts can serve as bio-control agents in alternative to traditional agrochemicals. In this study, we aim to identify biosynthetic gene clusters (BGCs) from plant-associated bacterial genomes that can produce secondary metabolites with an impact on plant growth. To achieve this goal, we built a genome dataset with over 1,000 plant-associated bacteria and over 1,500 non-plant-associated ones. Through a comparative analysis on the BGCs predicted by antiSMASH in these genomes, we found that several classes of BGCs are enriched in plant-associated bacteria genomes, which may play a crucial role in mediating plant-microbe interactions. In search for individual BGCs producing metabolites that impact plant growth, we assembled over 100 plant-associated metagenome samples and examined the sequence abundance of BGCs in these samples. Using the result of 20 BGCs that are known to impact plant growth as positive controls, we were able to identify a list of BGCs that have potential impact on plant growth. We are experimentally validating the bioactivity of two novel secondary metabolites from the list. This study represents the first study to systematically and comprehensively analyze plant-associated secondary metabolism. By an integration of different bioinformatic tools including genome-mining, biostatistics and metagenome mapping, we expand the metabolome-based understanding of plant-microbe interactions and provide potential leads for efficient and sustainable agricultural via microbiome engineering.