A combination of comparative genomics and LAESI-MS facilitates the discovery of amino acid analogs produced by plant-associated bacteria
R. OKRENT (1), K. Trippe (1), V. Manning (1), E. Davis (2), C. Walsh (3) (1) USDA-ARS, U.S.A.; (2) Oregon State University, U.S.A.; (3) Protea Biosciences, Inc., U.S.A.

Non-proteinogenic amino acids produced by microbes mediate many processes in host-microbe and microbe-microbe interactions. Oxyvinylglycine metabolites from bacteria inhibit pyridoxyl phosphate-utilizing enzymes such as those involved in nitrogen metabolism and ethylene biosynthesis. The oxyvinylglycine 4-formylaminooxyvinylglycine (FVG) was originally identified in strains of Pseudomonas fluorescens isolated from the rhizosphere of wheat and other grasses. FVG arrests the germination of weedy grasses and inhibits the growth of the bacterial plant pathogen Erwinia amylovora. In the sequenced strain P. fluorescens WH6, we have previously demonstrated that a 13-kb gene cluster containing 12 genes with regulatory, biosynthetic, and transport functions is required for FVG production. Homologous clusters are present in other strains distributed throughout the Pseudomonas genus. We sequenced the genomes of seven of these strains and analyzed these and other available genomes for the presence of FVG-associated genes. In order to test the ability of strains to produce FVG, we developed a new high-throughput methodology with minimal sample processing utilizing LAESI-MS. We found that most strains containing the FVG cluster produce FVG. Analysis of gene context suggests that the cluster was introduced multiple times within the Pseudomonas lineage. In addition, clusters containing a subset of the genes required to produce FVG were identified in a broad range of bacteria, including many non-pseudomonads, and likely produce novel metabolites. This work has broadened our understanding of an understudied class of compounds that have importance in mediating host-microbe and microbe-microbe interactions.

Abstract Number: C4-5, P3-87
Session Type: Concurrent