Project description:Bacteria in the genus Pantoea (family Enterobacteriales) are metabolically diverse, cosmopolitan, and form a wide range of interactions with eukaryotic hosts including plants, fungi, insects and humans. Several Pantoea species have pathogenic interactions with plants. Strains of at least four Pantoea species (P. ananatis, P. allii, P. stewartii subsp. indologenes and P. agglomerans) are known to cause onion center rot disease. P. ananatis is very unusual among characterized bacterial plant pathogens. Virulence factors that distinguish onion-virulent and non-virulent P. ananatis have only recently been described. Most bacterial plant pathogens are dependent on specialized virulence protein secretion systems for pathogenicity. However, to cause plant cell death, P. ananatis instead requires the HiVir (High Virulence) proposed secondary metabolite synthetic cluster for an as of yet undescribed phosphonate compound. P. allii is also pathogenic on onion but, surprisingly, lacks the HiVir gene cluster associated with onion-virulent P. ananatis. P. allii carries a completely distinct predicted phosphonate compound synthetic cluster which has, interestingly, also been identified in P. stewartiii subsp indologenes that have expanded their host range from millet onto onions. We obtained the cell pellet metabolite profiles of P. ananatis PNA 97-1, the P. allii type strain LMG 24248, and the two corresponding biosynthetic mutant strains lacking a key gene (pepM) for the synthesis of phosphonate compounds. Understanding the unique chemistry of onion-virulent Pantoea will yield important insights into novel frameworks for plant- pathogen interactions.
The work (proposal:https://doi.org/10.46936/10.25585/60001193) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
